Academic literature on the topic 'Chromosome. eng'
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Journal articles on the topic "Chromosome. eng"
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Yan, Wenzhong, and Lei Bai. "Algorithms for Chromosome Classification." Engineering 05, no. 10 (2013): 400–403. http://dx.doi.org/10.4236/eng.2013.510b081.
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Qureshi, Salman T., Philippe Gros, Michelle Letarte, and Danielle Malo. "The murine endoglin gene (Eng) maps to chromosome 2." Genomics 26, no. 1 (March 1995): 165–66. http://dx.doi.org/10.1016/0888-7543(95)80099-8.
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Corinaldesi, Giorgio. "Hereditary Haemorrhagic Telangiectasia Spectrum of ALK1/ENG Mutation." Blood 116, no. 21 (November 19, 2010): 5066. http://dx.doi.org/10.1182/blood.v116.21.5066.5066.
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Abstract Abstract 5066 Hereditary hemorrhagic telangiectasia (HHT) is an autosomal dominant disease characterized by two common criteria: angiodysplastic mucocutaneous telangiectasies, and epistaxis; hematemesis, melena, hemoptysis, stroke and visceral artero-venous malformation (AVMv) have also been associated with a significant risk of morbidity and mortality; HHT is divided into two forms: HHT-1 which is caused by a mutation in ENG (endoglin) gene mapping on chromosome 9q33–34, and HHT-2 which is caused by a mutation in ALK1 (activin receptor-like kinase 1) gene mapping on the pericentromeric region of chromosome 12q12–13. Endoglin is an homodimeric disulphide-linked integral membrane glycoprotein (CD105) expressed on endothelial cells of all vessels; it binds TGF-beta 1 and 3, and it is very important to mediate vascular remodelling, the increase of blood flow, cellular migration and adhesion, extracellular matrix synthesis, through the modulation on endothelial cells, smooth muscle cells, fibroblasts and pericytes. ALK1 increases in response to vessel wall stress or injury, and has a specific role in the differentiation of new vessels. The majority of mutations in both genes are null, nonsense or splite-site and are non coding; the spectrum of mutations that have been reported of the two genes are short insertions, deletions, or missense and are present with a high level of consanguinity; homozygous patients with these mutations have severe haemorrhages. We have identified on chromosome 12 a large deletion in exon 7, (8.4 kbp long fragment) of ALK1 encoding for the extracellular ligand-bindig domain involved in the TGF-beta/kinase activity signalling pathway, and in exon 8 (6.4 kbp long fragment) of ALK1 encoding serine-threonine kinase activity. The latter was a 28-year-old woman showing skin telangiectasies, recurrent and significant nosebleeds; the typical puntiform telangiectasies were evident since the age of 16, she also demonstrated with gastrointestinal endoscopy numerous gastric telangiectasies; abdominal and thoracic CT were performed and pulmonary involvement was present with a single artero-venous malformation and minimal respiratory symptoms (dyspnea, cyanosis); on the other hand, MRN did not revealed any cerebrovascular damage. Mutations that disrupt ALK1 affect endothelial cells development and the process of angiogenesis; they are associated with mild clinical manifestation, and it has been observed that pulmonary arteriovenous malformations occur less frequently. Disclosures: No relevant conflicts of interest to declare.
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Shabaldin, A. V., A. V. Tsepokina, O. V. Dolgikh, E. V. Shabaldina, and A. V. Ponasenko. "Combination of HLA-DRB1 alleles as a factor causing risks of sporadic congenital heart defects and congenital malformations without chromosome diseases." Health Risk Analysis, no. 1 (March 2021): 133–42. http://dx.doi.org/10.21668/health.risk/2021.1.14.eng.
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Congenital heart defects are anomalies that are becoming more and more frequent every year. Their specific weight is the highest among all the defects and malformations in fetus. Besides, children with sporadic congenital heart defects and malformations are still born rather frequently. We made an assumption that congenital heart defects (CHD) and congenital malformations (CM) were formed due to inflammatory process decompensation within «mother – fetus» system occurring in case of a conflict as per HLA between a semi-allogenic fetus and its mother’s microenvironment. A risk of such a conflict might be associated with certain HLA combinations in parents’ genotypes. Our research goal was to reveal peculiarities of HLA-DRB1 alleles combinations in married couples who had children with sporadic CHD and CM without any chromosome diseases and to determine whether such peculiarities could cause risks of congenital anomalies. We determined frequency of 14 alleles in HLA-DRB1 gene in all people who took part in the research. Our research allowed establishing that parents whose children suffered from CHD more frequently had common HLA-DRB104, female HLA-DRB107 with male HLA-DRB113, HLA-DRB117 and female HLA-DRB113 with male HLA-DRB114. Children who suffered from CM more frequently had parents who were homologous as per HLA-DRB112, as well as with female HLA-DRB112 and male HLA-DRB101, HLA-DRB104, HLA-DRB113, and HLA-DRB115; this greater frequency was statistically significant. We also detected an authentic increase in frequency of HLA-DRB112 allele in children against their parents. Children with CM also had HLA-DRB112 allele statistically significantly more frequently than healthy children. Peculiarities related to HLA-DRB1 alleles combination are genetic predictors of CHD and CM occurrence; their determination will allow minimizing risks of such disorders due to early diagnostics and timely prevention.
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Lo, Anthony W. I., Carl N. Sprung, Bijan Fouladi, Mehrdad Pedram, Laure Sabatier, Michelle Ricoul, Gloria E. Reynolds, and John P. Murnane. "Chromosome Instability as a Result of Double-Strand Breaks near Telomeres in Mouse Embryonic Stem Cells." Molecular and Cellular Biology 22, no. 13 (July 1, 2002): 4836–50. http://dx.doi.org/10.1128/mcb.22.13.4836-4850.2002.
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ABSTRACT Telomeres are essential for protecting the ends of chromosomes and preventing chromosome fusion. Telomere loss has been proposed to play an important role in the chromosomal rearrangements associated with tumorigenesis. To determine the relationship between telomere loss and chromosome instability in mammalian cells, we investigated the events resulting from the introduction of a double-strand break near a telomere with I-SceI endonuclease in mouse embryonic stem cells. The inactivation of a selectable marker gene adjacent to a telomere as a result of the I-SceI-induced double-strand break involved either the addition of a telomere at the site of the break or the formation of inverted repeats and large tandem duplications on the end of the chromosome. Nucleotide sequence analysis demonstrated large deletions and little or no complementarity at the recombination sites involved in the formation of the inverted repeats. The formation of inverted repeats was followed by a period of chromosome instability, characterized by amplification of the subtelomeric region, translocation of chromosomal fragments onto the end of the chromosome, and the formation of dicentric chromosomes. Despite this heterogeneity, the rearranged chromosomes eventually acquired telomeres and were stable in most of the cells in the population at the time of analysis. Our observations are consistent with a model in which broken chromosomes that do not regain a telomere undergo sister chromatid fusion involving nonhomologous end joining. Sister chromatid fusion is followed by chromosome instability resulting from breakage-fusion-bridge cycles involving the sister chromatids and rearrangements with other chromosomes. This process results in highly rearranged chromosomes that eventually become stable through the addition of a telomere onto the broken end. We have observed similar events after spontaneous telomere loss in a human tumor cell line, suggesting that chromosome instability resulting from telomere loss plays a role in chromosomal rearrangements associated with tumor cell progression.
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Spell, R. M., and C. Holm. "Nature and distribution of chromosomal intertwinings in Saccharomyces cerevisiae." Molecular and Cellular Biology 14, no. 2 (February 1994): 1465–76. http://dx.doi.org/10.1128/mcb.14.2.1465.
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To elucidate yeast chromosome structure and behavior, we examined the breakage of entangled chromosomes in DNA topoisomerase II mutants by hybridization to chromosomal DNA resolved by pulsed-field gel electrophoresis. Our study reveals that large and small chromosomes differ in the nature and distribution of their intertwinings. Probes to large chromosomes (450 kb or larger) detect chromosome breakage, but probes to small chromosomes (380 kb or smaller) reveal no breakage products. Examination of chromosomes with one small arm and one large arm suggests that the two arms behave independently. The acrocentric chromosome XIV breaks only on the long arm, and its preferred region of breakage is approximately 200 kb from the centromere. When the centromere of chromosome XIV is relocated, the preferred region of breakage shifts accordingly. These results suggest that large chromosomes break because they have long arms and small chromosomes do not break because they have small arms. Indeed, a small metacentric chromosome can be made to break if it is rearranged to form a telocentric chromosome with one long arm or a ring with an "infinitely" long arm. These results suggest a model of chromosomal intertwining in which the length of the chromosome arm prevents intertwinings from passively resolving off the end of the arm during chromosome segregation.
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Spell, R. M., and C. Holm. "Nature and distribution of chromosomal intertwinings in Saccharomyces cerevisiae." Molecular and Cellular Biology 14, no. 2 (February 1994): 1465–76. http://dx.doi.org/10.1128/mcb.14.2.1465-1476.1994.
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To elucidate yeast chromosome structure and behavior, we examined the breakage of entangled chromosomes in DNA topoisomerase II mutants by hybridization to chromosomal DNA resolved by pulsed-field gel electrophoresis. Our study reveals that large and small chromosomes differ in the nature and distribution of their intertwinings. Probes to large chromosomes (450 kb or larger) detect chromosome breakage, but probes to small chromosomes (380 kb or smaller) reveal no breakage products. Examination of chromosomes with one small arm and one large arm suggests that the two arms behave independently. The acrocentric chromosome XIV breaks only on the long arm, and its preferred region of breakage is approximately 200 kb from the centromere. When the centromere of chromosome XIV is relocated, the preferred region of breakage shifts accordingly. These results suggest that large chromosomes break because they have long arms and small chromosomes do not break because they have small arms. Indeed, a small metacentric chromosome can be made to break if it is rearranged to form a telocentric chromosome with one long arm or a ring with an "infinitely" long arm. These results suggest a model of chromosomal intertwining in which the length of the chromosome arm prevents intertwinings from passively resolving off the end of the arm during chromosome segregation.
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Gonzalez de la Rosa, Pablo Manuel, Marian Thomson, Urmi Trivedi, Alan Tracey, Sophie Tandonnet, and Mark Blaxter. "A telomere-to-telomere assembly ofOscheius tipulaeand the evolution of rhabditid nematode chromosomes." G3 Genes|Genomes|Genetics 11, no. 1 (December 8, 2020): 1–17. http://dx.doi.org/10.1093/g3journal/jkaa020.
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AbstractEukaryotic chromosomes have phylogenetic persistence. In many taxa, each chromosome has a single functional centromere with essential roles in spindle attachment and segregation. Fusion and fission can generate chromosomes with no or multiple centromeres, leading to genome instability. Groups with holocentric chromosomes (where centromeric function is distributed along each chromosome) might be expected to show karyotypic instability. This is generally not the case, and in Caenorhabditis elegans, it has been proposed that the role of maintenance of a stable karyotype has been transferred to the meiotic pairing centers, which are found at one end of each chromosome. Here, we explore the phylogenetic stability of nematode chromosomes using a new telomere-to-telomere assembly of the rhabditine nematode Oscheius tipulae generated from nanopore long reads. The 60-Mb O. tipulae genome is resolved into six chromosomal molecules. We find the evidence of specific chromatin diminution at all telomeres. Comparing this chromosomal O. tipulae assembly with chromosomal assemblies of diverse rhabditid nematodes, we identify seven ancestral chromosomal elements (Nigon elements) and present a model for the evolution of nematode chromosomes through rearrangement and fusion of these elements. We identify frequent fusion events involving NigonX, the element associated with the rhabditid X chromosome, and thus sex chromosome-associated gene sets differ markedly between species. Despite the karyotypic stability, gene order within chromosomes defined by Nigon elements is not conserved. Our model for nematode chromosome evolution provides a platform for investigation of the tensions between local genome rearrangement and karyotypic evolution in generating extant genome architectures.
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Lukhtanov, Vladimir A., Vlad Dincă, Magne Friberg, Jindra Šíchová, Martin Olofsson, Roger Vila, František Marec, and Christer Wiklund. "Versatility of multivalent orientation, inverted meiosis, and rescued fitness in holocentric chromosomal hybrids." Proceedings of the National Academy of Sciences 115, no. 41 (September 28, 2018): E9610—E9619. http://dx.doi.org/10.1073/pnas.1802610115.
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Chromosomal rearrangements (e.g., fusions/fissions) have the potential to drive speciation. However, their accumulation in a population is generally viewed as unlikely, because chromosomal heterozygosity should lead to meiotic problems and aneuploid gametes. Canonical meiosis involves segregation of homologous chromosomes in meiosis I and sister chromatid segregation during meiosis II. In organisms with holocentric chromosomes, which are characterized by kinetic activity distributed along almost the entire chromosome length, this order may be inverted depending on their metaphase I orientation. Here we analyzed the evolutionary role of this intrinsic versatility of holocentric chromosomes, which is not available to monocentric ones, by studying F1 to F4 hybrids between two chromosomal races of the Wood White butterfly (Leptidea sinapis), separated by at least 24 chromosomal fusions/fissions. We found that these chromosomal rearrangements resulted in multiple meiotic multivalents, and, contrary to the theoretical prediction, the hybrids displayed relatively high reproductive fitness (42% of that of the control lines) and regular behavior of meiotic chromosomes. In the hybrids, we also discovered inverted meiosis, in which the first and critical stage of chromosome number reduction was replaced by the less risky stage of sister chromatid separation. We hypothesize that the ability to invert the order of the main meiotic events facilitates proper chromosome segregation and hence rescues fertility and viability in chromosomal hybrids, potentially promoting dynamic karyotype evolution and chromosomal speciation.
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Röpke, Albrecht, and Frank Tüttelmann. "MECHANISMS IN ENDOCRINOLOGY: Aberrations of the X chromosome as cause of male infertility." European Journal of Endocrinology 177, no. 5 (November 2017): R249—R259. http://dx.doi.org/10.1530/eje-17-0246.
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Male infertility is most commonly caused by spermatogenetic failure, clinically noted as oligo- or a-zoospermia. Today, in approximately 20% of azoospermic patients, a causal genetic defect can be identified. The most frequent genetic causes of azoospermia (or severe oligozoospermia) are Klinefelter syndrome (47,XXY), structural chromosomal abnormalities and Y-chromosomal microdeletions. Consistent with Ohno’s law, the human X chromosome is the most stable of all the chromosomes, but contrary to Ohno’s law, the X chromosome is loaded with regions of acquired, rapidly evolving genes, which are of special interest because they are predominantly expressed in the testis. Therefore, it is not surprising that the X chromosome, considered as the female counterpart of the male-associated Y chromosome, may actually play an essential role in male infertility and sperm production. This is supported by the recent description of a significantly increased copy number variation (CNV) burden on both sex chromosomes in infertile men and point mutations in X-chromosomal genes responsible for male infertility. Thus, the X chromosome seems to be frequently affected in infertile male patients. Four principal X-chromosomal aberrations have been identified so far: (1) aneuploidy of the X chromosome as found in Klinefelter syndrome (47,XXY or mosaicism for additional X chromosomes). (2) Translocations involving the X chromosome, e.g. nonsyndromic 46,XX testicular disorders of sex development (XX-male syndrome) or X-autosome translocations. (3) CNVs affecting the X chromosome. (4) Point mutations disrupting X-chromosomal genes. All these are reviewed herein and assessed concerning their importance for the clinical routine diagnostic workup of the infertile male as well as their potential to shape research on spermatogenic failure in the next years.
Dissertations / Theses on the topic "Chromosome. eng"
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Maziviero, Guilherme Thiago. "Avaliação do potencial citotóxico, genotóxico e mutagênico de esgoto por meio dos sistemas-teste Allium cepa e Tradescantia pallida /." Rio Claro : [s.n.], 2011. http://hdl.handle.net/11449/87700.
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Orientador: Carmem Silvia Fontanetti ChristofolettiBanca: Tatiana da Silva Souza
Banca: Ana Cristina Mielli
Resumo: O lodo de esgoto pode conter substâncias tóxicas, estar contaminado com metais pesados e até mesmo por compostos químicos persistentes, sendo assim, a disposição inadequada desse resíduo pode fazer tais poluentes retornarem ao ambiente e, eventualmente, entrar na cadeia alimentar, caso sejam absorvidos pelas plantas. O conhecimento dos agentes químicos presentes no lodo permite avaliar o risco de contaminação alimentar e ambiental decorrente da utilização de lodos como fertilizantes agrícolas, também chamados de biossólidos. Logo, o presente estudo teve por objetivo avaliar o potencial genotóxico, citotóxico e mutagênico do lodo gerado por uma Estação de Tratamento de Esgoto (ETE), por meio dos sistemas-teste Allium cepa e Tradescantia pallida. As coletas foram realizadas em abril de 2009 e maio de 2010 e os organismos foram expostos ao lodo bruto e seu solubilizado. Quando comparados os resultados obtidos nos bioensaios com as análises físico-químicas, não é possível estabelecer relação de causa e efeito com nenhum composto em específico, uma vez que todos os parâmetros avaliados se encontram dentro dos limites estabelecidos pela Resolução CONAMA 375; no entanto, em ambos os organismos, o lodo apresentou-se genotóxico e mutagênico, alertando sobre a necessidade de cuidado na disponibilização deste tipo de resíduo em solos. Dessa forma é possível concluir que os ensaios de toxicidade genética são capazes de identificar os efeitos diretos do lodo de esgoto e poderiam ser contemplados pela legislação como ferramenta complementar à bateria de testes já estabelecida devido à simplicidade dos testes e custo relativamente reduzido. O trabalho traz ainda uma revisão de literatura sobre a utilização da espécie Tradescantia, suas bases e aplicações das técnicas do pêlo estaminal (Trad-SHM) e teste o do micronúcleo (Trad- MCN), apontando suas... (Resumo completo, clicar acesso eletrônico abaixo)
Abstract: Sewage sludge can contain toxic substances, may be contaminated with heavy metals and persistent chemicals, so the improper disposal of this waste can return such pollutants to the environment and possibly return to the food chain if absorbed by plants. The knowledge of chemical agents present in the sludge can assess the risk of food contamination and environmental arising from the use of sludge as agricultural fertilizer, also called biosolids. Therefore, this study aimed to evaluate the potential genotoxic, cytotoxic and mutagenic of sludge generated from a Wastewater Treatment Plant (WTP) by the Allium cepa and Tradescantia pallida tests-systems. Samples were collected in April 2009 and May 2010 and the organisms were exposed to raw sludge and its solublilizated samples. Comparing the results obtained in bioassays with the physico-chemical properties, its cannot establish cause and effect relationship with any compound in particular, since all parameters are within limits set by CONAMA Resolution 375, however, in both organisms, the sludge showed genotoxic and mutagenic, and warns about caution in providing this type of waste in soils. Thus, we conclude that the genetic toxicity tests are able to identify the direct effects of sewage sludge and could be provided by the law as a complementary tool to the battery of tests previously established, due to the simplicity of the tests and relatively low cost. The work also contains a review on the use of Tradescantia species, their bases and applications of the techniques of stamen hair (Trad-SHM) and the micronucleus test (Trad-MCN), pointing out its advantages as a tool for monitoring of environmental health
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Boschiero, Clarissa 1979. "Mapeamento fino de qtls e polimorfismos de genes candidatos associados ao crescimento no cromossomo 1 da galinha /." Botucatu : [s.n.], 2009. http://hdl.handle.net/11449/104869.
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Orientador: Ana Silvia Alves Meira Tavares MouraBanca: Luiz Lehmann Coutinho
Banca: Mônica Corrêa Ledur
Banca: Millor Fernandes do Rosário
Banca: José Roberto Sartori
Resumo: A partir de resultados de um estudo anterior, no qual foram mapeados QTLs para características de peso vivo, peso do coração e pulmões no GGA1, foi definida uma região no intervalo entre os marcadores ADL0234 e LEI0071, abrangendo 82,3 cM. Foram avaliadas três famílias de meios-irmãos paternos que compreendiam sete famílias de irmãos completos, num total de 652 F2 para as características: peso vivo aos 35 e 41 dias de idade, pesos do coração e pulmões e rendimentos de coração e pulmões. Os genótipos de seis marcadores microssatélites foram adicionados aos dez utilizados anteriormente. O mapa de ligação obtido da região compreendeu 110,8 cM com espaçamento médio entre os marcadores de 7,4 cM. Na análise de F2, em um único intervalo (LEI0146-LEI0174), compreendendo 28,8 cM, foram mapeados QTLs para todas as características estudadas, com exceção dos rendimentos de coração e pulmões. Neste intervalo estão localizados o gene IGF1 e o centrômero do cromossomo. A adição de seis marcadores confirmou os QTLs mapeados anteriormente, porém alguns em diferentes posições. A análise de meios-irmãos paternos indicou que os principais QTLs estavam segregando em apenas uma das famílias (7716), na qual cinco QTLs foram mapeados. Na análise de meios-irmãos maternos, duas famílias segregaram QTLs tanto na análise Individual como na Conjunta (7810 e 7971). As diferentes análises permitiram selecionar dois casais F1, que devem ser o alvo dos próximos estudos. Este estudo restringiu a busca por genes candidatos responsáveis pelas características de interesse a uma região de 28,8 cM (9,82 Mb) no GGA1.
Abstract: Based on the results from a previous study, in which QTL for body weight, heart and lungs weights and heart and lungs percentages were mapped to GGA1, a region was defined between markers ADL0234 and LEI0071, spanning 82.3 cM. Three paternal half-sib families, comprising seven full-sib families, totaling 652 F2 were evaluated for body weight at 35 and 41 days of age, heart and lungs weights and heart and lungs yields. Genotypes of six microsatellite markers were added to those of ten previously used. The linkage map of this region spanned 110.8 cM, with average spacing of 7.4 cM between markers. In a single interval (LEI0146-LEI0174), comprising 28.8 cM, QTLs for all traits, except for heart and lungs yields were mapped in the F2 analysis. In this same interval the IGF1 gene, and the chromosome centromere, are located. The use of six additional markers confirmed the same QTLs mapped previously, but some of them, in different positions. The paternal half-sib analysis indicated that the main QTLs were segregating in one of the families only (7716), in which five QTLs were mapped. In the maternal half-sib analysis, two families segregated QTLs both, in the across and within families analyses (7810 and 7971). These analyses allowed the selection of two F1 couples to be the target for future studies. This study restricted the search for candidate genes responsible for the traits of interest to a region of 28.8 cM (9.82 Mb) in GGA1.
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Abril, Vanessa Veltrini. "Evolução cromossômica no veado-mateiro - Mazama americana (Mammalia; Cervidae) /." Jaboticabal : [s.n.], 2009. http://hdl.handle.net/11449/102780.
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Orientador: José Maurício Barbanti DuarteBanca: Fausto Foresti
Banca: Cláudio de Oliveira
Banca: Orlando Moreira Filho
Banca: Vera Fernanda Martins Hossepian de Lima
Resumo: Estudos com veado-mateiro (Mazama americana) mostram que há muitas controvérsias quanto ao número de subespécies ou até quanto ao desdobramento destas em espécies. Em estudo citotaxonômico foram encontradas variações cromossômicas intra e interpopulacionais em populações de M. americana geograficamente distantes, com número diplóide de 48 a 53 e número fundamental de 46 a 57. Com base nisto, o presente estudo visou compreender como ocorreu a reorganização cromossômica dentro das variantes encontradas durante a evolução do grupo. Para isto, estrutura e organização dos cromossomos de M. americana foram analisadas para identificar os rearranjos que originaram a variação intraespecífica através das técnicas de bandamento cromossômico (bandas G, C, Ag-NOR), hibridação in situ (FISH) com sondas teloméricas e pintura cromossômica com o uso de sondas cromossômicas da espécie Mazama gouazoubira. Foram identificados seis citótipos distribrídos em 12 cariótipos diferentes: Rondônia (2n=42 ou 43 e NF=46; 2n=42 e NF=49), Juína (2n= 43, 44 ou 45 e NF=48; 2n=44 e NF=46), Jarí (2n=49; NF=56, Carajás (2n=50 e NF=54), Santarém (2n=51 e NF=56) e Paraná (2n=51,52 ou 53 e NF=56). O cariótipo básico do citótipo Paraná foi utilizado como base comparativa para os demais. Os rearranjos que originaram essas diferenças foram fusões cêntricas, em tandem e inversões pericêntricas. A análise de complexo sinaptonêmico confirmou a existência de um sistema sexual múltiplo do tipo XX/XY1Y2 através da detecção de uma trivalente sexual. Sítios teloméricos intersticiais evidenciam que a ocorrência de eventos de fusões em tandem foi essencial para a evolução cariotípica desta espécie e a homologia de sondas cromossomo-específicas de M. gouazoubira corroboram que o caminho da reorganização cromossômica entre estas espécies foi principalmente através de fusões.
Abstract: Studies with the red brocket deer (Mazama americana) shown that there are a lot of controversies about the number of subspecies or about the unfolding of these in new species. Citotaxonomic studies found intra and interpopulational chromosomal variations, with diploid number varing from 48 to 53 and fundamental number from 46 to 57. Based on these studies, the aim of the present study was understood how the chromosomal reorganization occurred between this variants during the evolution process. For that, we analyzed the chromosomal structure and organization of M. americana, identifying the rearrangements responsible for the intraspecific variation through chromosome banding (G and C-banding, Ag-NOR), in situ hybridization of telomeric probes and chromosome painting using probes of M. gouazoubira species. It were found six different variants: Rondônia (2n=42 or 43 and FN=46; 2n=42 and FN=49), Juína (2n= 43, 44 or 45 and FN=48; 2n=44 and FN=46), Jarí (2n=49 and FN=56), Carajás (2n=50 and FN=54), Santarém (2n=51 and FN=56) and Paraná (2n=51,52 or 53 and FN=56). The basic karyotype of Paraná variant was choosing for comparative analysis. The rearrangements responsible for these chromosomal differences were centric and tandem fusions and pericentric inversions. The synaptonemal analysis sustained the existence of a multiple sexual system (XX/XY1Y2) with detection of a sexual trivalent. Intersticial telomeric sites shown the occurrence of tandem fusions was essential for the karyotype evolution of this species and the homology with the probes of M. gouazoubira corroborated that the way of chromosomal reorganization between these species was mainly through chromosome fusions.
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Melloni, Maria Natália Guindalini. "Determinação do número cromossômico de espécies arbóreas nativas com potencial madeireiro /." Jaboticabal : [s.n.], 2010. http://hdl.handle.net/11449/92687.
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Orientador: José Roberto MoroBanca: Herberte Pereira da Silva
Banca: Luciana Rossini Pinto
Resumo: O Brasil tem uma flora nativa exuberante, muito explorada e pouco estudada. A economia florestal brasileira tem importante papel na qualidade de vida do país sendo necessárias informações que possibilitem uma exploração mais consciente e sustentável das espécies nativas. Uma das formas de se obter esclarecimentos relevantes a respeito das espécies arbóreas do Brasil é por meio de estudos citogenéticos. Esses estudos cromossômicos podem fornecer informações importantes na taxonomia, evolução, genética, melhoramento de plantas e na preservação dos sistemas florestais. Por meio de técnicas de citogenética convencional estabeleceu-se o número cromossômico diplóide de: Balfourodendron riedelianum, 2n = 58 cromossomos, com tamanho médio dos cromossomos de 1,877μm ± 0,44, Cedrela fissilis, 2n = 56 cromossomos, com tamanho médio dos cromossomos de 1,01μm ± 0,26; Hymenaea courbaril var. stilbocarpa, 2n = 24 cromossomos, com tamanho médio dos cromossomos de 3,52μm ± 0,68 ; Myroxylon peruiferum, 2n=26 cromossomos, com tamanho médio dos cromossomos de 1,25μm ± 0,30; Pterogyne nitens, 2n=20 cromossomos, com tamanho médio dos cromossomos de 1,13μm ± 0,27; Tabebuia aurea, 2n = 40 cromossomos, com tamanho médio dos cromossomos de 1,05μm ± 0,23; T. ochracea , 2n=80 cromossomos, com tamanho médio dos cromossomos de 1,02μm ± 0,22 e C. odorata com variação cromossômica de 2n = 42 a 2n = 104 cromossomos. Os resultados obtidos neste trabalho poderão fornecer suporte para futuras pesquisas de manipulação dos cromossomos, comparação em estudos taxonômicos, estudos evolutivos, produção de progênies híbridas para fins comerciais e melhoramento genético de espécies madeireiras
Abstract: Brazil has a lush native flora, much exploited and little studied. The Brazilian forestry economy has an important role in the life quality of the country being necessary information to enable a more conscious and sustainable exploitation of native species. One way to obtain relevant details about the tree species in Brazil is through cytogenetic studies. These chromosome studies may provide important information on taxonomy, evolution, genetics and plant breeding as also as on the conservation of forest systems. Using conventional cytogenetics techniques the diploid chromosome number was established: Balfourodendron riedelianum, 2n = 58 chromosomes, with the average size of chromosomes 1, 877μm ± 0.44, Cedrela fissilis, 2n = 56 chromosomes, with the average size of chromosomes 1, 01μm ± 0.26; Hymenaea courbaril var. stilbocarpa, 2n = 24 chromosomes, with an average size of the chromosomes of 3.52 μm ± 0.68; Myroxylon peruiferum, 2n = 26 chromosomes, with the average size of chromosomes 1, 25μm ± 0.30; Pterogyne nitens, 2n = 20 chromosomes with average size of chromosomes 1, 13μm ± 0.27, Tabebuia aurea, 2n = 40 chromosomes, with an average size of the chromosomes of 1.05 μm ± 0.23; T. ochracea, 2n = 80 chromosomes, with an average size of the chromosomes of 1.02 ± 0.22 μm and Cedrela odorata with chromosome variation of 2n = 42 to 2n = 104 chromosomes. The results of this study may provide support for future research in chromosome manipulation, comparative taxonomy, evolutionary studies, commercial hybrid seed production and breeding timber species
Mestre
5
Christofoletti, Cintya Aparecida. "Avaliação dos potenciais citotóxico, genotóxico e mutagênico das águas de um ambiente lêntico, por meio dos sistemas-teste de Allium cepa e Oreochromis niloticus /." Rio Claro : [s.n.], 2008. http://hdl.handle.net/11449/87679.
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Orientador: Carmem Silvia Fontanetti ChristofolettiBanca: Maria Aparecida Marin Morales
Banca: Silvia Tamie Matsumoto
Resumo: A degradação dos recursos hídricos, como os ambientes lênticos, dentre eles, os lagos, é uma das maiores preocupações atualmente, visto que esta pode causar danos diretos ou indiretos à saúde e à sobrevivência dos organismos expostos. Um dos fatores que contribui para a alteração da qualidade das águas de ambientes lênticos é o despejo de efluentes, principalmente àqueles de origem doméstica, portadores de substâncias que chegam a ser tóxicas para o meio aquático. Por meio dos testes citogenéticos, utilizando os mais diversificados organismos-teste, é possível biomonitorar a extensão da poluição e avaliar os efeitos dessas substâncias presentes no ambiente natural. Com esse intuito, o presente trabalho tomou por modelo de estudo, um lago urbano artificial (Lago Azul, Rio Claro-SP) e objetivou avaliar o potencial citotóxico, genotóxico e mutagênico das águas desse ambiente, por meio dos testes de aberrações cromossômicas e micronúcleos, em células meristemáticas de Allium cepa (cebola), em dois tratamentos: o contínuo e o período de recuperação, em água ultra pura; e, pelo teste do micronúcleo associado às anormalidades nucleares e do ensaio do cometa, aplicados em eritrócitos de Oreochromis niloticus (tilápia). Coletas de águas sazonais foram realizadas na estação seca (agosto/2006 e agosto/2007) e na estação chuvosa (março/2007 e fevereiro/2008). Análises físico-químicas foram feitas para uma coleta de cada estação. A partir dos dados obtidos, pode-se inferir que as águas desse ambiente lêntico apresentam potencial citotóxico, genotóxico e mutagênico, nas duas estações de coletas, para os dois organismos-teste empregados. As análises de metais revelaram concentrações acima do permitido pela legislação de Ag, Cd2+, Cu e Fe3+, em ambas as estações. Embora os... (Resumo completo, clicar acesso eletrônico abaixo)
Abstract: The degradation of water resources, as the lentics environments, among them, the lakes, is a major concern now, because it can cause direct or indirect damages to health and to the survival of the exposed organisms. One factor that can contribute to change the water quality of lentics environments is the dumping of effluents, mainly those of domestic origin, carriers of substances that come to be toxic to the aquatic environment. Through the cytogenetic tests, using the most diverse systems-test, it is possible monitoring the extent of pollution and assess the effects of substances on the natural environment. To that end, this work has taken a model of study, an urban artificial lake (Lago Azul, Rio Claro-SP) and aimed to evaluate the cytotoxic, genotoxic and mutagenic potentials of waters that environment, through tests of chromosome aberrations and micronuclei in meristematic cells of Allium cepa (onion) in two treatments: the continued and the period of recovery, in ultra pure water, and by the micronucleus and nuclear abnormalities test and of the comet assay, applied in erythrocytes of Oreochromis niloticus (tilapia). Seasonal collections of waters were held in the dry season (august/2006 and august/2007) and the rainy season (march/2007 and february/2008). Physical and chemical analyses were made for a collection of each season. From the data obtained, it can be infered that the waters of this lentic environment had cytotoxic, genotoxic and mutagenic potentials in two seasons of collections for the two systems-test employed. Analyses of metals detected high concentrations of Ag, Cd2+, Cu, Fe3+, whose values are higher than permitted by law, in both seasons. Although the cytotoxic, genotoxic and mutagenic potentials have been detected in two seasons, the dry season is that presented the highest risk... (Complete abstract click electronic access below)
Mestre
6
Pedro, Janaina. "Detecção da citotoxicidade, genotoxicidade e mutagenicidade do inseticida fipronil no organismo teste Allium cepa /." Rio Claro : [s.n.], 2008. http://hdl.handle.net/11449/87704.
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Orientador: Maria Aparecida Marin MoralesBanca: Carmem Silvia Fontanetti Christofoletti
Banca: Mateus Mondin
Resumo: Os agrotóxicos constituem uma importante estratégia da agricultura, para a obtenção de uma produtividade economicamente viável, pois são substâncias utilizadas no combate de organismos indesejáveis. Os inseticidas são agentes que têm ação de combater insetos, tanto na fase adulta como larval. O fipronil é um composto do grupo fenil-pirazol, toxicologicamente classificado como altamente tóxico, amplamente utilizado em campos agrícolas do estado de São Paulo, bem como nas residências, para combater insetos pragas. A ação deste inseticida se dá pela sua ligação ao canal de cloro, promovendo o bloqueio da ativação da condução dos estímulos nervosos, pelo ácido gama-aminobutírico (GABA), uma substância que controla o fluxo de íons cloro, através da membrana da célula nervosa. Em pequenas concentrações, apresenta uma eficiente ação nos organismos alvos. Esta característica também pode causar problemas ao meio ambiente, muitas vezes, longe até dos lugares onde foi aplicado. O fipronil, em temperaturas moderadas, é estável no ambiente por cerca de um ano. Estudos mostram que esse inseticida pode ser degradado em diversos metabólitos, que são ainda mais tóxicos que ele. Quanto a sua persistência no ambiente, o fipronil apresenta variações decorrentes da sua formulação, mas os seus metabólicos podem ser mais persistentes que o próprio inseticida. Resíduos de fipronil podem ser bioacumulado no tecido adiposo, indicando uma potencialidade de transferência via cadeia trófica. No presente trabalho, foram avaliadas as potencilidades tóxicas, citotóxicas, genotóxicas e mutagênicas do inseticida fipronil, por meio de bioensaios com Allium cepa, cujas sementes foram expostas à germinação em fipronil.
Abstract: The pesticides are an important strategy for agriculture, to obtain productivity economically viable, because they are substances used to eliminate pest organisms. Insecticides are agents which have action to combat insects, in both the adult and larval stage. The fipronil is a group composed of phenyl-pyrazole, toxicologically classified as highly toxic, and it is widely used in agricultural fields in Sao Paulo State, as well as in homes, to combat insect pests. This insecticide acts through its connection to the channel chlorine, promoting blockade in the activation of the conduct of nervous stimuli, the gamma-aminobutyric acid (GABA), a substance that controls the flow of chloride ions through the cell membrane of nerve. In small concentrations, presents an efficient action in the organism targets. This feature can also cause problems to the environment, often far to the places where it is applied. In moderate temperatures, the fipronil is stable in the environment for about a year. Studies show that this insecticide can be degraded in various metabolites, which are even more toxic than the fipronil. Relative to its persistence in the environment, the fipronil presents variations resulting from its formula, but their metabolites may be more persistent than the insecticide. Residues of fipronil can be bioacumulated in adipose tissue, indicating a potential of transference by the food chain. In the present research, it had been evaluated the toxic, cytotoxic, genotoxic and mutagenic potentials of the fipronil insecticide through bioassays with Allium cepa, whose seeds were exposed to germination in this insecticide. The results indicate that the insecticide presented no toxic and cytotoxic effects for the A. cepa species, when we compared the data resulting from the tests performed with the insecticide and with the negative control.
Mestre
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Figueiredo, Raquel de Freitas. "Estudo de SNPs do cromossomo Y na população do Estado do Espirito Santo, Brasil /." Araraquara : [s.n.], 2012. http://hdl.handle.net/11449/87818.
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Orientador: Regina Maria Barretto CicarelliBanca: Greiciane Gaburro Paneto
Banca: Raquel Mantuaneli Scarel Caminaga
Resumo: A identificação humana pela análise de DNA utiliza o perfil genético de um indivíduo baseado no estudo de uma combinação de marcadores que são herdados de seus progenitores. Os marcadores genéticos mais utilizados na rotina forense estão presentes nos cromossomos autossomos, porém, os marcadores presentes nos cromossomos sexuais (X e Y) e no DNA mitocondrial auxiliam as análises de forma eficiente. Assim, os marcadores do cromossomo Y têm sido muito estudados, pois além do campo forense, estes possuem várias aplicações no campo evolucionário, como na compreensão da genética populacional e exploração da história da evolução humana. Duas categorias principais são atualmente utilizadas para examinar o cromossomo Y: loci bialélico (polimorfismos de nucleotídeo único - SNPs - e inserção Alu) e loci multialélico (minissatélites e microssatélites - STRs). SNPs possuem várias vantagens em relação aos STRs, principalmente com amostras degradadas ou em pequena quantidade, devido a sua alta frequência, simplicidade, menor tamanho e baixa taxa de mutação. Assim, visando à ampliação dos dados da população brasileira em relação aos marcadores genéticos, este estudo teve por objetivo identificar os maiores haplogrupos existentes na população do Estado do Espírito Santo e avaliar as contribuições de Africanos, Ameríndios e Europeus na sua formação, uma vez que esse estado recebeu imigrantes de várias origens. Para isso, foram estudados 35 Y-SNPs em 255 amostras de indivíduos do sexo masculino nascidos no Estado do Espírito Santo - Brasil. A genotipagem foi realizada por PCR seguida por minisequenciamento (SNaPshot Multiplex) e detecção por eletroforese capilar no analisador genético ABI3500 (Applied Biosystems by Life Technologies). Dos 38 haplogrupos possíveis de serem classificados... (Resumo completo, clicar acesso eletrônico abaixo)
Abstract: Human identification by DNA analysis uses the genetic profile of an individual studying a combination of markers inherited from their parents. The genetic markers most widely used in routine forensic are present in the autosomes, however, the markers present in sex chromosomes (X and Y) and mitochondrial DNA helps analysis efficiently. Thus, the Y chromosome markers have been widely studied because beyond the forensic field, they have several applications in the field of evolution, such as in the understanding of population genetics and exploitation of human evolutionary history. Two main categories are currently used to examine the Y chromosome: biallelic loci (single nucleotide polymorphisms - SNPs - and Alu insertion) and multiallelic loci (minisatellites and microsatellites - STRs). SNPs have several advantages over STRs, especially with degraded or in small quantities samples, due to its high frequency, simplicity, small size and low mutation rate. Thus, aiming to increase the data of the brazilian population related to genetic markers, the objective of this study was to identify the major haplogroups existing in the population of Espirito Santo and evaluate the contribution of Africans, Amerindians and Europeans in their formation, since this state has received immigrants from various origins. For this purpose, 35 Y-SNPs in 255 blood samples from male individuals born in Espirito Santo State-Brazil. Genotyping was performed by PCR followed by minisequencing reaction (SNaPshot Multiplex) and detection by capillary electrophoresis on ABI3500 genetic analyzer (Applied Biosystems by Life Technologies). Of the 38 possible haplogroups to be classified with the 35 SNPs studied, only 19 were detected in this sample. The haplogroup diversity was 0.7794±0.0229 and the most frequent haplogroup was... (Complete abstract click electronic access below)
Mestre
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Boschiero, Clarissa. "Mapeamento de locos de características quantitativas associados a desempenho e carcaça nos cromossomos 11 e 13 de Gallus gallus /." Botucatu : [s.n.], 2006. http://hdl.handle.net/11449/94757.
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Orientador: Ana Sílvia Alves Meira Tavares MouraBanca: Heraldo César Gonçalves
Banca: Mônica Corrêa Ledur
Resumo: O objetivo deste trabalho foi identificar locos controladores de características quantitativas (QTLs) nos cromossomos 11 e 13 de galinhas (Gallus gallus) para características de desempenho e carcaça. A partir do cruzamento entre uma linhagem de corte e uma de postura, foi gerada a população experimental F2 na Embrapa Suínos e Aves. Foram avaliadas as seguintes informações fenotípicas: peso ao nascer, peso aos 35, 41 e 42 dias, ganho de peso, consumo de ração, eficiência e conversão alimentar dos 35 aos 41 dias e valores de hematócrito. As carcaças foram evisceradas e avaliados: o comprimento do intestino, peso dos pulmões, do fígado, do coração e da moela. Foram obtidos após quatro horas de resfriamento: peso da carcaça, gordura abdominal, peso de partes: peito, coxas, dorso, asas, cabeça e pés. Quatro e cinco marcadores microssatélites dos cromossomos 11 e 13, respectivamente, foram genotipados num total aproximado de 330 animais F2 em quatro famílias de irmãos-completos. Os mapas de ligação para ambos os cromossomos foram construídos e a análise de mapeamento de QTLs baseada no modelo genético de F2 foi realizada. No cromossomo 11 foram mapeados dois QTLs sugestivos: para peso de pés e de moela, ambos posicionados no intervalo entre ADL0123 e ADL0210. No cromossomo 13 foi mapeado um QTL sugestivo para peso de coração posicionado no intervalo entre MCW0110 e MCW0104.
Abstract: The objective of this study was to identify quantitative trait loci (QTLs) for performance and carcass traits in chicken (Gallus gallus) chromosomes 11 and 13. From the crossbreeding of a broiler and a layer line, an F2 experimental population was generated at the Embrapa Suínos e Aves. The following phenotypic data were recorded: body weights at birth, 35, 41 and 42 d; weight gain, feed consumption and feed conversion from 35 to 41 d; weights of carcass, carcass parts, organs and abdominal fat, hematocrit and length of intestine. Four and five microsatellite markers from chromosomes 11 and 13, respectively, were genotyped in approximately 330 F2 chickens from four full-sib families. The linkage maps for both chromosomes were constructed and the QTL mapping analyses were carried out based on an F2 genetic model. Two suggestive QTLs were mapped to chromosome 11: for feet and gizzard weights, both located in the interval between ADL0123 and ADL0210. On chromosome 13 one suggestive QTL for heart weight was detected in the interval between MCW0110 and MCW0104.
Mestre
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Ventura, Bruna de Campos. "Investigação da mutagenicidade do azocorante comercial BDCP (Black Dye Commercial Product), antes e após tratamento microbiano, utilizando o sistema teste de Allium cepa /." Rio Claro : [s.n.], 2009. http://hdl.handle.net/11449/100573.
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Orientador: Maria Aparecida Marin-MoralesBanca: Maria Luiza Silveira Mello
Banca: Cláudia Bueno dos Reis Martinez
Banca: Maria Angélica Maciel Martinho Ferreira
Banca: Edson Luis Maístro
Resumo: Os azocorantes são substâncias químicas extremamente utilizadas em indústrias têxteis que podem induzir mudanças no material genético de organismos expostos, mesmo que essas alterações no DNA não se expressem de imediato. Foram avaliadas as citotoxicidade, genotoxicidade e mutagenicidade de diferentes concentrações (1, 10, 100 e 1000 mg/L - na ausência dos microorganismos - e 50 e 200 mg/L - na presença dos microorganismos) do azocorante Black Dye Commercial Product (BDCP), antes e após tratamentos de biodegradação por diversos microrganismos (1. "Pool" de bactérias heterotróficas provenientes de uma estação de tratamento biológico de efluentes, 2. Levedura Candida viswanathii, e 3. Fungo Basidiomiceto Phanerochaete chrysosporium), por meio de diferentes técnicas citogenéticas (coloração convencional, bandamento C, bandamento RON, bandamento por fluorocromos base-específicos CMA/DAPI e hibridação in situ fluorescente - FISH) aplicadas sobre o organismo teste Allium cepa. Pela técnica citogenética de coloração convencional, foi possível verificar que o corante, com e sem ação microbiana, induziu apoptose, necrose, células micronucleadas, aberrações cromossômicas e alterações nucleares. As aberrações cromossômicas e alterações nucleares foram visualizadas em todos os estágios do ciclo celular: na intérfase foram observados brotos nucleares e células poliplóides; na prófase, perdas de material genético; na metáfase, aderências cromossômicas, perdas cromossômicas, C-metáfases e poliploidias; na anáfase e telófase, multipolaridades, pontes e perdas cromossômicas. Os brotos nucleares apareceram com maior freqüência nas células submetidas aos testes do azocorante tratado com microorganismos, sendo que esse tipo de alteração deve estar associado à presença dos metabólitos do corante. As freqüências de micronúcleos... (Resumo completo, clicar acesso eletrônico abaixo)
Abstract: Azo dyes are chemical substances extremely used by textile industries that may induce changes in the genetic material of exposed organisms, even if these changes in the DNA do not express themselves immediately. Cytotoxicity, genotoxicity and mutagenicity evaluations of the different azo dye (BDCP) concentrations were performed (1, 10, 100 e 1000 mg/L - without microorganisms - and 50 and 200 mg/L - with microorganisms), before and after biodegradation tests, using different microorganisms (1. Heterotrofic bacteria "pool" proceeding from an effluent biological treatment station, 2. Candida viswanathii - Yeast, and 3. Phanerochaete chrysosporium - Basidiomicet Fungi), by means the different cytogenetical assays (conventional staining, C-banding, RON-banding, CMA/DAPI banding and fluorescent in situ fluorescent hybridization), using Allium cepa as test organism. By the conventional staining cytogenetic assay, it was possible to verify that the azo dye induced apoptosis, necrosis, micronuclei, chromosome aberrations and nuclear alterations. The chromosome aberrations and nuclear alterations were visualized in all phases of the cell cycle: in the interphase were observed nuclear buds and polyploidizated cells; in the prophase were observed genetic material losses; in the metaphase were observed chromosome adherences, chromosome losses, C-metaphases and polyploid cells; and in the anaphase and telophase were observed multipolar cells, chromosome bridges and chromosome losses. The frequencies of nuclear buds were the higher when the cells had been submitted to the azodye treated with microorganisms, suggesting that this kind of alteration must be associated to the presence of the azodye metabolites. The micronuclei and chromosome breaks frequencies... (Complete abstract click electronic access below)
Doutor
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Santana, André Marcos. "Contribuição ao mapeamento do cromossomo 9 do búfalo de rio (Bubalus bubalis) utilizando painel de células somáticas híbridas irradiadas /." Jaboticabal : [s.n.], 2008. http://hdl.handle.net/11449/98196.
Full textAbstract:
Resumo: O búfalo de rio (Bubalus bubalis) é uma espécie de interesse econômico pertencente à família Bovidae, utilizado para a produção de carne e leite, além de força de trabalho no campo, constituindo-se em um animal de tripla aptidão. Recentemente, a construção de um painel de células somáticas híbridas irradiadas (linhagens celulares) contendo fragmentos do genoma do búfalo de rio, incorporado ao genoma de hamster (BBURH5000), está permitindo, pela primeira vez, o mapeamento de todos os cromossomos bubalinos. A utilização desse painel de células associado a análises estatísticas, está gerando mapas genômicos de alta resolução contendo diferentes tipos de marcadores moleculares. O presente trabalho teve por objetivo utilizar este painel de células para gerar grupos de ligação com os marcadores mapeados no cromossomo 9 bubalino e assim comparar a organização dos grupos de ligação obtidos com aqueles já descritos para o cromossomo 7 bovino. Para tal, foram testados com DNA bubalino, seqüências de "primers" para PCR de 26 marcadores moleculares previamente mapeados no cromossomo 7 bovino, o qual foi descrito na literatura como o homólogo ao cromossomo 9 de búfalo. Do total de marcadores testados, 18 geraram produtos de PCR adequados ao mapeamento utilizando o painel BBURH5000, sendo que destes 18, foi possível a genotipagem final de 10 marcadores. A partir das análises de ligação com os 10 marcadores genotipados, foi possível distribuir os mesmos em três grupos de ligação no BBU9. A análise comparativa entre os grupos de ligação do BBU9 e do BTA7 revelou a presença dos mesmos grupos de ligação nos cromossomos de ambas espécies, evidenciando conservação de sintenia.Abstract: The river buffalo (Bubalus bubalis), a member of the Bovidae family, is an economically important livestock specie useful to produce milk and meat, as well as source of labor, comprising an animal of triple aptness. The recent construction of a whole-genome 5000-rad radiation hybrid somatic cell panel for the river buffalo genome (BBURH5000), is allowing for the first time the mapping of all chromosomes from the specie. The use of BBURH5000 panel associated with statistical analyses is generating high-resolution RH maps integrating different types of molecular markers. The goal of this study was to genarate linkage groups with the markers mapped on the river buffalo chromosome 9 (BBU9), using the BBURH5000 panel, and then compare these groups with those already described in BTA7. Previous studies have identified bovine chromosome 7 as homologous to BBU9. Cattle derived PCR primers from 26 markers, previously mapped in cattle, were tested with buffalo DNA. A total of 18 of the 26 markers amplified PCR products suitable for RH mapping. From these 18 markers, it was possible the genotyping of 10. The analyses of linkage with the 10 markers genotyped turned possible to distribute them in three linkage groups on the BBU9. The comparative analyses between the linkage groups of BBU9 and BTA7 revealed the presence of the same linkage groups on the chromosome of both species, revealing conservation of synteny between them.
Orientadora: Maria Elisabete Jorge Amaral
Coorientadora: Vera Fernanda Martins H. de Lima
Banca: Humberto Tonhati
Banca: Simone Cristina Méo Niciura
Mestre
Books on the topic "Chromosome. eng"
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Iwao, Nishiya, Cram L. Scott, and Gray Joe W, eds. Flow cytometry and image analysis for clinical applications: Proceedings of the International Symposium on Flow Cytometry and Image Analysis for Clinical Applications, Morioka and Hanamaki, Iwate, Japan, July 1-3, 1990. Amsterdam: Excerpta Medica, 1991.
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Peter, Copeland, ed. The science of desire: The search for the gay gene and the biology of behavior. New York: Simon & Schuster, 1995.
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1957-, Copeland Peter, ed. The science of desire: The search for the gay gene and the biology of behavior. New York: Simon & Schuster, 1994.
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4
McKinlay Gardner, R. J., and David J. Amor. Autosomal Ring Chromosomes. Edited by R. J. McKinlay Gardner and David J. Amor. Oxford University Press, 2018. http://dx.doi.org/10.1093/med/9780199329007.003.0011.
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Ring chromosomes are uncommon. The typical physical phenotype comprises major dysmorphogenesis and intellectual deficiency, and reproduction is not usually a relevant issue. A ring chromosome is formed due to an end-to-end fusion of chromosome tips. Almost always, the end result is an imbalance and significant phenotypic abnormality. Rarely, however, this is not the case. In this chapter, genetic risks for ring carriers for whom procreation is a realistic likelihood are considered. This chapter distinguishes between those with a normal 46 chromosome count, one being a ring, and those with a 47 chromosome count, the additional chromosome being a (necessarily small) ring.
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Larramendy, Marcelo L., ed. Telomere - A Complex End of a Chromosome. InTech, 2016. http://dx.doi.org/10.5772/60625.
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McKinlay Gardner, R. J., and David J. Amor. Gonadal Cytogenetic Damage from Exposure to Extrinsic Agents. Edited by R. J. McKinlay Gardner and David J. Amor. Oxford University Press, 2018. http://dx.doi.org/10.1093/med/9780199329007.003.0024.
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This chapter is a compendium of what is known about the susceptibility, or resistance, of the gonad to agents that might seem candidates for possibly causing damage, and with particular reference to chromosomal status of gametes. A main focus is on cancer treatments. A majority of children and young adults who receive modern cancer treatment survive. Some treatments cause sterility, but in quite a number, fertility is unscathed, or at any rate, subsequently recovers. The chapter also references industrial, environmental, and recreational factors. A notable and substantially reassuring conclusion from these data is the apparent dearth of instances of an extrinsic factor having caused a chromosome abnormality in the sperm or egg of an exposed person.
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Powell, Craig M. PTEN and Autism With Macrocepaly. Oxford University Press, 2013. http://dx.doi.org/10.1093/med/9780199744312.003.0010.
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Phosphatase and Tensin homolog deleted on chromosome 10 (PTEN) is a gene encoding an intracellular signaling molecule. PTEN was originally discovered as the gene responsible for a subset of familial hamartoma (tumor) syndromes associated with increased risk for certain cancers (Nelen et al., 1997) and as a gene often mutated in human cancers and tumor cell lines (Li et al., 1997; Steck et al., 1997). More recently, mutations in PTEN have been linked genetically to the clinical phenotype of autism or developmental delay with macrocephaly (Boccone et al., 2006; Butler et al., 2005; Buxbaum et al., 2007; Goffin, Hoefsloot, Bosgoed, Swillen, & Fryns, 2001; Herman, Butter, et al., 2007; McBride et al., 2010; Orrico et al., 2009; Stein, Elias, Saenz, Pickler, & Reynolds, 2010; Varga, Pastore, Prior, Herman, & McBride, 2009; Zori, Marsh, Graham, Marliss, & Eng, 1998). This chapter examines the role of PTEN in intracellular signaling, the link between PTEN signaling pathways and other autism-related genes and signaling pathways, the genetic relationship between PTEN and autism, model systems in which effects of Pten deletion on the brain have been studied, and promising preclinical data identifying therapeutic targets for patients with autism/macrocephaly associated with PTEN mutations.
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McKinlay Gardner, R. J., and David J. Amor. Insertions. Edited by R. J. McKinlay Gardner and David J. Amor. Oxford University Press, 2018. http://dx.doi.org/10.1093/med/9780199329007.003.0008.
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Insertions are a type of translocation, and indeed they are sometimes referred to as “insertional translocation,” “interstitial translocation,” or “nonreciprocal translocation.” Here, a segment of one chromosome is removed and inserted within another chromosome (in contradistinction to the usual translocation, in which the translocated segment is attached to the end of a recipient chromosome). It is, essentially, a one-way translocation; that is, there is no reciprocal movement back to the originating chromosome. Insertions are rare rearrangements, at the level of detection according to classical cytogenetics. Insertions have their own specific qualities that influence risk assessment, and these are discussed in this chapter.
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Chambers, Professor Robert. Egg Maturation, Chromosomes, and Spermatogenesis in Cyclops (Classic Reprint). Forgotten Books, 2018.
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Test No. 483: Mammalian Spermatogonial Chromosome Aberration Test. OECD Publishing, 1997. http://dx.doi.org/10.1787/9789264071469-en.
Full textBook chapters on the topic "Chromosome. eng"
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Cech, Thomas R., and Joachim Lingner. "Telomerase and the Chromosome end Replication Problem." In Novartis Foundation Symposia, 20–40. Chichester, UK: John Wiley & Sons, Ltd., 2007. http://dx.doi.org/10.1002/9780470515433.ch3.
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Zhang, J., M. Baens, M. Chaffanet, J. Aerssens, J. J. Cassiman, and P. Marynen. "Isolation and Characterisation of NotI-end Cosmids Mapping to Human Chromosome 12p." In Chromosome 12 Aberrations in Human Solid Tumors, 173–80. Berlin, Heidelberg: Springer Berlin Heidelberg, 1994. http://dx.doi.org/10.1007/978-3-662-06255-5_17.
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Huppi, K., B. A. Mock, P. Schricker, L. A. D’Hoostelaere, and M. Potter. "Organization of the Distal End of Mouse Chromosome 4." In Genetics of Immunological Diseases, 276–88. Berlin, Heidelberg: Springer Berlin Heidelberg, 1988. http://dx.doi.org/10.1007/978-3-642-50059-6_42.
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Laskey, Ronald A., Richard M. Harland, and Marcel Méchali. "Induction of Chromosome Replication During Maturation of Amphibian Oocytes." In Ciba Foundation Symposium 98 - Molecular Biology of Egg Maturation, 25–43. Chichester, UK: John Wiley & Sons, Ltd, 2008. http://dx.doi.org/10.1002/9780470720790.ch3.
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Maresca, Thomas J., and Rebecca Heald. "Methods for Studying Spindle Assembly and Chromosome Condensation in Xenopus Egg Extracts." In Xenopus Protocols, 459–74. Totowa, NJ: Humana Press, 2006. http://dx.doi.org/10.1007/978-1-59745-000-3_33.
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Pajkrt, E. "Chromosomale afwijkingen en andere genetische syndromen." In Echoscopie in de verloskunde en gynaecologie, 289–304. Houten: Bohn Stafleu van Loghum, 2016. http://dx.doi.org/10.1007/978-90-368-1451-5_21.
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Lieber, Michael R., Jiafeng Gu, Haihui Lu, Noriko Shimazaki, and Albert G. Tsai. "Nonhomologous DNA End Joining (NHEJ) and Chromosomal Translocations in Humans." In Subcellular Biochemistry, 279–96. Dordrecht: Springer Netherlands, 2009. http://dx.doi.org/10.1007/978-90-481-3471-7_14.
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Petitpierre, Eduard, and Carlos Juan. "Genome size, chromosomes, and egg-chorion ultrastructure in the evolution of Chrysomelinae." In Novel aspects of the biology of Chrysomelidae, 213–25. Dordrecht: Springer Netherlands, 1994. http://dx.doi.org/10.1007/978-94-011-1781-4_14.
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Niu, Xiangli, Yanping Lao, Yan Sun, and Weihua Wang. "Next-Generation Sequencing Revealed that High Proportion of Human Embryos Resulted from Donor Eggs Are Segmental Chromosome Abnormal." In Cytogenetics [Working Title]. IntechOpen, 2020. http://dx.doi.org/10.5772/intechopen.95457.
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High proportion of human embryos produced by in vitro fertilization (IVF) are aneuploidy or have segmental chromosomal errors. Not only a whole chromosome aneuploidy, but also small errors in a chromosome, such as microdeletion can be detected by current next-generation sequencing (NGS) for preimplantation genetic testing (PGT). The prevalence of aneuploidy in donor egg IVF was significantly different between fertility clinics. In the present study, we examined whether different embryo biopsy procedures affect embryonic aneuploidies in donor egg IVF. We did not find significant differences in the samples with abnormal chromosomes between two biopsy methods. When we further analyzed the samples with abnormal chromosomes, we found that 64.0–80.7% of the abnormalities were whole chromosome aneuploidies while 19.3–36.0% were segmental chromosome abnormalities. High embryo implantation rates were obtained after transferring screened euploid blastocysts. These results indicate that blastocyst biopsy procedures may not significantly affect embryo’s chromosomal status, but PGT by high-resolution NGS revealed that high proportions of human embryos derived from donor eggs are not only aneuploidy, but also segmental chromosome abnormal, and screening of small chromosomal errors by NGS is beneficial to patients who use donated eggs for infertility treatment.
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Niu, Xiangli, Yanping Lao, Yan Sun, and Weihua Wang. "Next-Generation Sequencing Revealed that High Proportion of Human Embryos Resulted from Donor Eggs Are Segmental Chromosome Abnormal." In Cytogenetics - Classical and Molecular Strategies for Analysing Heredity Material. IntechOpen, 2021. http://dx.doi.org/10.5772/intechopen.95457.
Full textAbstract:
High proportion of human embryos produced by in vitro fertilization (IVF) are aneuploidy or have segmental chromosomal errors. Not only a whole chromosome aneuploidy, but also small errors in a chromosome, such as microdeletion can be detected by current next-generation sequencing (NGS) for preimplantation genetic testing (PGT). The prevalence of aneuploidy in donor egg IVF was significantly different between fertility clinics. In the present study, we examined whether different embryo biopsy procedures affect embryonic aneuploidies in donor egg IVF. We did not find significant differences in the samples with abnormal chromosomes between two biopsy methods. When we further analyzed the samples with abnormal chromosomes, we found that 64.0–80.7% of the abnormalities were whole chromosome aneuploidies while 19.3–36.0% were segmental chromosome abnormalities. High embryo implantation rates were obtained after transferring screened euploid blastocysts. These results indicate that blastocyst biopsy procedures may not significantly affect embryo’s chromosomal status, but PGT by high-resolution NGS revealed that high proportions of human embryos derived from donor eggs are not only aneuploidy, but also segmental chromosome abnormal, and screening of small chromosomal errors by NGS is beneficial to patients who use donated eggs for infertility treatment.
Conference papers on the topic "Chromosome. eng"
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Bosma, P. J., E. A. van den Berg, and T. Kooistra. "ISOLATION OF THE GENE CODING FOR HUMAN PLASMINOGEN ACTIVATOR INHIBITOR TYPE 1 (PAI-1)." In XIth International Congress on Thrombosis and Haemostasis. Schattauer GmbH, 1987. http://dx.doi.org/10.1055/s-0038-1644440.
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A human placenta genomic DNA cosmid library was screened for the presence of the PAI-1 gene using a cDNA probe coding for PAI-1. Two overlapping recombinant cosmids were obtained that contain human DNA spanning 55 kb. The cosmids were mapped using 3' and 5' end probes isolated from an almost full-length cDNA clone of 2.5 kb. The two cosmids were found to contain the entire structural PAI-1 gene (approximately 15 kb) and also included 25 kb 5' flanking sequences. The transcription initiation site was identified by SI nuclease protection experiments and the promotor region was sequenced. Further experiments will be directed at characterizing the regulatory elements of the PAI-1 gene.In order to determine the chromosomal localization of the PAI-1 gene we have hybridized our genomic clones in situ to metaphase chromosomes of a human blood cell culture. Preliminary experiments show a specific hybridization signal which will enable us to sublocalize the chromosomal position of the PAI-1 gene.
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Wu, Yirui, Yisheng Yue, Xiao Tan, Wei Wang, and Tong Lu. "End-To-End Chromosome Karyotyping with Data Augmentation Using GAN." In 2018 25th IEEE International Conference on Image Processing (ICIP). IEEE, 2018. http://dx.doi.org/10.1109/icip.2018.8451041.
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Lafont, J., J. H. Catherine, M. Lejeune, U. Ordioni, R. Lan, and F. Campana. "Manifestations buccales de la sclérose tubéreuse de Bourneville." In 66ème Congrès de la SFCO. Les Ulis, France: EDP Sciences, 2020. http://dx.doi.org/10.1051/sfco/20206603014.
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L’objectif de ce travail est de faire le point sur les manifestations buccales de la sclérose tubéreuse de Bourneville (STB) à travers le cas d’un jeune patient. Un jeune homme de 15 ans était adressée pour la mise en place de minivis orthodontique afin de fermer des espaces d’agénésies de 35 et 45. L’interrogatoire retrouvait une STB dont les manifestations épileptiques étaient traitées par de la lamotrigine 75mg/j et de la carbamazépine LP 200mg/j. L’examen clinique exo-buccal retrouvait des macules hypochromiques sur le membre inférieur droit, des angiofibromes faciaux et une malformation vasculaire jugale gauche. L’examen endo-buccal retrouvait de multiples lésions buccales sur les papilles interdentaires pouvant évoquer des fibromes ou des hamartomes. Une biopsie était réalisée et retrouvait un revêtement malpighien, discrètement hyperplasique et sans atypie cellulaire. Les faisceaux collagènes du conjonctif étaient mêlés à de nombreux fibroblastes aux noyaux réguliers, sans mitose visible. Les cellules inflammatoires, essentiellement mononuclées, étaient dispersées mais tendaient à se regrouper autour de vaisseaux nombreux et hyperplasiques. L’examen concluait à un fibrome. Aucun traitement buccal n’était proposé devant l’absence de symptôme et de demande esthétique. La STB est une maladie génétique autosomique dominante avec une incidence de 1/10 000. Elle est liée à une mutation du gène TSC1 sur le chromosome 9 ou du gène TSC2 sur le chromosome 16 qui perturbe la sécrétion d’une protéine régulant la voie mTOR. C’est une maladie multisystème avec une expression clinique variable. Les principaux symptômes sont l’épilepsie, le retard mental et la présence d’adénomes sébacés, mais la maladie est associée à un polymorphisme clinique rendant le diagnostic difficile. La conférence de consensus de 2012 a ainsi défini des critères diagnostiques majeurs (lésions cutanées, oculaires, cérébrales, cardiaques, pulmonaires, rénales,..) et mineurs dont deux sont bucco-dentaires. Le diagnostic est retenu devant deux critères majeurs ou un critères majeur et deux critères mineurs. Les signes oraux sont la présence de trois ou plus puits d’émail et deux ou plus fibromes gingivaux. Les fibromes gingivaux atteindraient 50 à 70% des patients. La région antérieure maxillaire semble la plus touchée. L’exérèse est indiquée en cas de gêne esthétique ou de saignements associés. Actuellement, les inhibiteurs de mTOR représentent une option thérapeutique proposée dans la prise en charge des patients atteints de STB. La STB est une pathologie rare. La présence de lésions buccales fait partie des critères diagnostiques.
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Liddell, M. B., D. S. Anson, D. P. Lillicrap, and I. R. Peake. "SEARCH FOR AND USE OF RESTRICTION FRAGMENT LENGTH POLYMORPHISMS (RFLPs) IN AND AROUND THE HUMAN FACTOR IX GENE." In XIth International Congress on Thrombosis and Haemostasis. Schattauer GmbH, 1987. http://dx.doi.org/10.1055/s-0038-1644078.
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5 previously described RFLPs within the factor IX gene have been used for family studies (carrier detection) in 10 haemophilia B kindred. In all DNA from 91 individuals, including 25 obligate or possible carriers, was analysed by digestion with TaqI and XmnI and probing with the intragenomic probe VIII (all probes were provided by Professor G. G. Brownlee, Oxford). When noninformative, additional RFLPs (DdeI;probe XIII and MspI;probe II) were used. Of 12 possible carriers, 11 were diagnosed (6 as carriers, 5 normal). Of the confirmed carriers (6 diagnosed, 13 obligate) 15 were informative (heterozygous and phase known), and the overall incidence of heterozygosity was 72%. The recently reported BamHI RFLP was not found to be useful ( <1.0% frequency).Further RFLPs in and flanking the factor IX gene were sought by two procedures. Firstly cosmid pCHIXα, containing a 40kb insert including the 3' end of the factor IX gene and stretching some 35kb 3' to the gene was used as a large probe, with repetitive sequences being blocked by preannealing the probe with an excess of sonicated, denatured human DNA (Litt and White, PNAS 82, 6206). Results with 25 restriction enzymes (covering an estimated 1038 nucleotides) and DNA from 7 unrelated females were obtained, but only one low frequency PvuII RFLP (frequency about 1%) was identified. Similar experiments with further cosmid probes 3' to the gene are underway. The second technique was developed to analyse small DNA fragments (<1.0kb) generated by frequently cutting restriction enzymes. These fragments were separated on 3.5% polyacrylamide/0.5% agarose composite gels and then electroblotted onto hybond-N. Fragments of 150bp were readily visualised by this procedure. 3 frequently cutting enzymes have been used (Hinfl, Rsal and Mbol), and the blots probed with a factor IX c-DNA probe, or a unique sequence subclone of cosmid pCHIXα. To date no RFLPs have been identified. This search for further useful RFLP has illustrated the paucity of detectable sequence variation within this region of the X-chromosome.
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Oujdad, S., S. Zafad, H. El Attar, and I. Ben Yahya. "Histiocytose langerhansienne de l’adulte : à propos d’un cas." In 66ème Congrès de la SFCO. Les Ulis, France: EDP Sciences, 2020. http://dx.doi.org/10.1051/sfco/20206603013.
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L’histiocytose langerhansienne est une maladie rare causée par la prolifération et l’infiltration d’un ou plusieurs organes, par des cellules dendritiques de type Langerhans. Elle s’exprime par des manifestations cliniques extrêmement polymorphes et peut toucher l’os, la peau, l’hypophyse, les poumons, le système nerveux central, et plus rarement le foie et le système digestif. Elle a été initialement décrite chez les enfants. L’histiocytose langerhansienne de l’adulte présente une entité particulière tant par ses manifestations cliniques que par sa prise en charge. Le cas présenté est celui d’un patient âgé de 53ans, en bon état de santé apparent et non fumeur, qui s’est présenté à la consultation pour des lésions nécrotiques et douloureuses des muqueuses gingivales mandibulaires et maxillaires, associées à des mobilités dentaires sévères. L’examen exobuccal ne révélait aucune asymétrie faciale ni adénopathies. L’examen endobuccal confirmait la présence de lésions nécrotiques gingivales et une parodontite sévère au niveau mandibulaire antérieur et maxillaire postérieur. Le secteur maxillaire antérieur présentait un parodonte sain. L’examen radiologique panoramique et Cone Beam CT , révélaient des lyses osseuses moyennes à terminales s’étendant de la 44 à la 38 et au niveau des molaires maxillaires droites et gauches. Les dents antérieures ne présentaient quant à elles pas de lyse. Par ailleurs des images lacunaires à l’emporte pièce siégeaient au niveau du secteur mandibulaire édenté. Ces manifestations évoquaient un lymphome ou une manifestation orale d’une infection virale type VIH. L’examen biologique révélait une légère hyperleucocytose et une augmentation de la vitesse de sédimentation à la première heure. L’examen anatomopathologique des lésions muqueuses, a rapporté la présence d’éléments histiocytaires se regroupant en nodules, concluant en une histiocytose langerhasienne de l’adulte. Le bilan d’extension ne révélait aucune atteinte associée, concluant en une histiocytose localisée. L’étude moléculaire a montré la présence d’une mutation V600E du gène BRAF (Facchetti et al, European journal of pathology, 471(4); 2017). Ce dernier est situé sur le chromosome 7, et il est impliqué dans l’envoi des signaux qui déterminent la croissance cellulaire. L’évolution et le pronostic de cette maladie sont étroitement liés à l’âge et aux organes atteints. Les régressions spontanées ont été rapportées, et peuvent être induites par un curetage ou par une simple biopsie. (Goncalves et al, Biomedical research notes,9(19); 2016) Pour notre cas, les extractions des dents mobiles avec curetage des lésions ont permis une cicatrisation complète. La thérapeutique médicamenteuse peut comprendre une corticothérapie locale ou systémique, des bisphosphonates, voire même une radiothérapie. Par ailleurs la confirmation de la mutation BRAF permet d’oser un traitement spécifique par inhibition de l’enzyme produite par ce gène. (Martıénez et al, Revisita Odontologica Mexicana, 16(2 ); 2012)
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Edenbrandt, C.-M., S. Gershagen, P. Femlund, R. Wydro, J. Stenflo, and Å. Lundwall. "GENE STRUCTURE OF VITAMIN K-DEPENDENT PROTEIN S; A REGION HOMOLOGOUS TO SEX HORMONE BINDING GLOBULIN (SHBG) REPLACES THE SERINE PROTEASE REGION OF FACTORS IX, X AND PROTEIN C." In XIth International Congress on Thrombosis and Haemostasis. Schattauer GmbH, 1987. http://dx.doi.org/10.1055/s-0038-1644640.
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It has recently been shown that the similarity between coagulation factors IX, X and protein C in the protein sequence is also evident in the organization of their genes. To further elucidate the relation of protein S to the other vitamin K-dependent clotting factors, we are now characterizing the human protein S gene. The size of the gene was estimated to be more than 45 kb, by hybridization of a cDNA for human protein S with chromosomal DNA in a Southern blot.We have isolated three overlapping clones from a human genomic DNA library in bacteriophage λ Charon 4A, which cover approximately 40 kb of the gene. The clones have been mapped by single- and double restriction enzyme digestion. Genomic subclones in pUC 18 which hybridize with cDNA probes for protein S have been isolated and sequenced to establish the intron/exon structure of the gene. The 5’- part of the human protein S gene closely resembles the corresponding part of the genes for factors IX, X and protein C. However, the thrombin sensitive region (amino acids 46-75), which is unique for protein S among the vitamin K-dependent clotting factors, is coded for by a separate exon. The 3'- end of the protein S gene, coding for amino acids 247-635, is not homologous to the catalytic region of the vitamin K-dependent serine proteases but shows a significant homology to human sex hormone binding globulin (SHBG).
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Menon, Shankar, Luis Valencia, and Lucien Teunckens. "The Nuclear Decommissioner and the Regulation of Low Dose Radiation." In ASME 2003 9th International Conference on Radioactive Waste Management and Environmental Remediation. ASMEDC, 2003. http://dx.doi.org/10.1115/icem2003-4665.
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The management of the large quantities of very low level radioactive material that arise during the decommissioning of the increasing numbers of nuclear power stations reaching the end of their commercially useful lives, has become a major subject of discussion. This has very significant economic implications for the nuclear decommissioner. Much larger quantities — 2–3 orders of magnitude larger — of material, radiologically similar to the candidate material for recycling from the nuclear industry, arise in non-nuclear industries like coal, fertiliser, oil and gas, mining, etc. In such industries, naturally occurring radioactivity is artificially concentrated in products, by-products or waste to form TENORM (Technologically Enhanced Naturally Occurring Radioactive Material). It is only in the last decade that the international community has become aware of the prevalence of TENORM, specially the activity levels and quantities arising in so many non-nuclear industries. The first reaction of international organisations seems to have been to propose different standards for the nuclear and non-nuclear industries, with very stringent release criteria for radioactive material from the regulated nuclear industry and up to thirty to a hundred times more liberal criteria for the release/exemption of TENORM from the as yet unregulated non-nuclear industries. The radiological effects of these TENORM releases have recently been dramatically highlighted by the Marina II study, which showed that over 90% of the total exposures of the European population from discharges into the North European marine waters are from radioactive discharges from non-nuclear industries. The results of an international project to validate, by actual measurement, dose calculation codes RESRAD-RECYCLE (USA) and CERISE (France) for recycling, have indicated an overestimation of doses by the codes by an order of magnitude. For the nuclear decommissioner and other producers of large volumes of slightly radioactively contaminated material, clearance levels determined on the basis of such a degree of conservatism in calculations can lead to huge volumes of material unnecessarily being condemned to burial as radioactive waste. Earlier estimates of the quantitative risk levels of exposure to ionising radiation have almost exclusively been based on doses taken by exposed populations of Hiroshima and Nagasaki (ICRP 60). The populations studied have been exposed to over 200 mSv at a dose rate of 6 Sv/s. The effects of such high dose/dose-rate exposure are being used as the basis for risk judgment at doses/dose-rates lower by a factor 1012–1015. The validity of such an extrapolation in risk judgement is an area of prime interest for discussion. In this connection, an interesting development, for both the nuclear and non-nuclear industries, is the increased scientific scrutiny that the populations of naturally high background dose level areas of the world are being subject to. Preliminary biological studies have indicated that the inhabitants of such areas, exposed to many times the permitted occupational doses for nuclear workers, have not shown any differences in cancer mortality, life expectancy, chromosome aberrations or immune function, in comparison with those living in normal background areas. The paper discusses these and other strategic issues regarding the management of redundant low radiation material from both the nuclear and non-nuclear industries, underlining the need for consistency in regulatory treatment.
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Pannekoek, H., M. Linders, J. Keijer, H. Veerman, H. Van Heerikhuizen, and D. J. Loskutoff. "THE STRUCTURE OF THE HUMAN ENDOTHELIAL PLASMINOGEN ACTIVATOR INHIBITOR (PAI-1) GENE: NON-RANDOM POSITIONING OF INTRONS." In XIth International Congress on Thrombosis and Haemostasis. Schattauer GmbH, 1987. http://dx.doi.org/10.1055/s-0038-1644767.
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The endothelium plays a crucial role in the regulation of the fibrinolytic process, since it synthesizes and secretes tissue-type plasminogen activator (t-PA) as well as the fast-acting plasminogen activator inhibitor (PAI-1). Molecular cloning of full-length PAI-1 cDNA, employing a human endothelial cDNA expression library, and a subsequent determination of the complete nucleotide sequence, allowed a prediction of the amino-acid sequence of the PAI-1 glycoprotein. It was observed that the amino-acid sequence is significantly homologous to those of members of the serine protease inhibitor ("Serpin") family, e.g. αl-antitrypsin and antithrombin III. Serpins are regulators of various processes, such as coagulation, inflammatory reactions, complement activation and share a common functional principle and a similar structure, indicative for a common primordial gene. The intron-exon arrangement of Serpin genes may provide a record for the structure of a primordial gene. A comparison of the location of introns among members of the Serpin family reveals that some introns are indeed present at identical or almost identical positions, however in many other cases there is no correspondence between the intron positions among different Serpin genes.Obviously, more data on the chromosomal gene structure of members of this family are required to formulate a scheme for the evolutionary creation of the Serpins. To that end, we have established the number and the precise location of the introns in the PAI-1 gene and have compared these data with those reported on other Serpin genes. For that purpose a human genomic cosmid DNA library of about 340.000 independent colonies was screened with radiolabelled full-length PAI-1 cDNA as probe. Two clones were found which contain the entire PAI-1 gene. Restriction site mapping, electron microscopic inspection of heteroduplexes and nucleotide sequence analysis demonstrate that the PAI-1 gene comprises about 12.2kilo basepairs and consists of nine exons and eight introns. Intron-exon boundaries are all in accord with the "GT-AG" rule, including a cryptic acceptor splice site found in intron 7. Furthermore, it is observed that intron 3 of the PAI-1 gene occupies an identical position as intron E of chicken ovalbumin and intron E of the ovalbumin-related gene Y. The location of the other seven introns is unrelated to the known location of introns in the genes encoding the Serpins, rat angiotensin, chicken ovalbumin (and gene Y), human antithrombin III and human al-antitrypsin. The 3' untranslated region of the PAI-1 gene is devoid of introns, indicating that the two mRNA species detected in cultured endothelial cells which share an identical 5' untranslated segment and codogenic region, but differ in the length of the 3' untranslated region, arise by alternative polyadenylation. An extrapolation of the position of the introns to the amino-acid sequence of PAI-1, and adaption of the view that the subdomain structure of the Serpins is analogous, shows that the introns of PAI-1 are non-randomly distributed. Except for intron 7, the position of the other seven introns corresponds with randon-coil regions of the protein or with the borders of β-sheets and a-helices. Extrapolation of the position of introns in the genes of other Serpins to their respective amino-acid sequences and subdomain structures also reveals a preference for random-coil regions and borders of subdomains. These observations are reminiscent of an evolutionary model, called "intron sliding", that accounts for variations in surface loops of the same protein in different species by aberrant splicing (Craik et al., Science 220 (1983) 1125). The preferential presence of introns in gene segments, encoding these variable regions, and absence in regions determining the general folding of these proteins would explain conservation of the structure during the evolution of those genes.