Siga este enlace para ver otros tipos de publicaciones sobre el tema: Coal darter.
Artículos de revistas sobre el tema "Coal darter"
Crea una cita precisa en los estilos APA, MLA, Chicago, Harvard y otros
Consulte los 32 mejores artículos de revistas para su investigación sobre el tema "Coal darter".
Junto a cada fuente en la lista de referencias hay un botón "Agregar a la bibliografía". Pulsa este botón, y generaremos automáticamente la referencia bibliográfica para la obra elegida en el estilo de cita que necesites: APA, MLA, Harvard, Vancouver, Chicago, etc.
También puede descargar el texto completo de la publicación académica en formato pdf y leer en línea su resumen siempre que esté disponible en los metadatos.
Explore artículos de revistas sobre una amplia variedad de disciplinas y organice su bibliografía correctamente.
1
Kreiser, Brian R., Scott R. Clark y Jacob F. Schaefer. "Microsatellite Loci for the Threatened Pearl Darter and Cross Amplification in Channel and Coal Darters". Journal of Fish and Wildlife Management 12, n.º 1 (29 de abril de 2021): 257–62. http://dx.doi.org/10.3996/jfwm-21-008.
Texto completoResumen
Abstract The Pearl Darter Percina aurora is an imperiled species of fish currently only found in the Pascagoula River drainage in southern Mississippi. We tested 60 microsatellite loci identified by Illumina pair-ended sequencing. Forty of these loci were polymorphic in Pearl Darters with a mean number of alleles per locus of 11.5 and mean observed and expected heterozygosity values of 0.818 and 0.805, respectively. Eleven to 17 of these loci were also polymorphic in the closely related Channel Darter P. copelandi and Coal Darter P. brevicauda. These loci should prove useful in genetic studies associated with informing future management decisions for Pearl Darters and conservation efforts in other species of darter.
2
Jones, Kenny D., Bernard R. Kuhajda y Michael W. Sandel. "Complete mitochondrial genome for the Mobile River Basin endemic Coal Darter, Percina brevicauda (Perciformes, Percidae)". Mitochondrial DNA Part B 4, n.º 1 (2 de enero de 2019): 2031–32. http://dx.doi.org/10.1080/23802359.2019.1617066.
Texto completo
3
Adamczyk, Zdzisław, Joanna Komorek y Małgorzata Lewandowska. "SPECIFIC TYPES OF COAL MACERALS FROM ORZESZE AND RUDA BEDS FROM ”PNIÓWEK” COAL MINE (UPPER SILESIAN COAL BASIN – POLAND) AS A MANIFESTATION OF THERMAL METAMORPHISM". Archives of Mining Sciences 59, n.º 1 (1 de marzo de 2014): 77–91. http://dx.doi.org/10.2478/amsc-2014-0006.
Texto completoResumen
Abstract Subject of the research were coal samples from the seams of Orzesze and Ruda beds from “Pniówek” coal mine. All samples represent methabituminous coal B, which present high vitrinite content (V mmf > 60%). Optical character of vitrinite from all analyzed coal samples is biaxial negative and it is characterized by low differentiation of bireflectance. The experiments have shown that the coal rank of investigated samples is generally decreasing with increasing both depth of coal seams and the distance between sampling point and the Carboniferous roof. It may suggests inversion of coalification. Specific types of macerals, typical for thermally metamorphosed coals have been found for all analysed coal samples. It was found, presence of such components like: fluorescing bituminous substance (FBS) filling of cellular spaces in semifusinite, fusinite, and funginite; pseudomorphs after megaspores exhibiting strong bireflectance, and anisotropic semifusinite. Petrographic components with a structure similar to structure of coke and pyrolytic carbon were observed rarely. Presence of colotelinite grains which are visible darker, impregnated with bituminous substance and exhibiting weak fluorescence may be related with influence of temperature on coal. Carbonates occur as filling of cellular spaces in semifusinite, in examined coal samples and there are the effect of thermal alteration of coal.
4
Cui, Chengwu. "Which color is more colorful, the lighter one or the darker one?" Color Research & Application 28, n.º 3 (junio de 2003): 168–74. http://dx.doi.org/10.1002/col.10142.
Texto completo
5
Heckaman, Rodney L. y Mark D. Fairchild. "Brighter, more colorful colors and darker, deeper colors based on a theme of brilliance". Color Research & Application 36, n.º 4 (23 de junio de 2010): 255–65. http://dx.doi.org/10.1002/col.20621.
Texto completo
6
Misiak, Jacek. "Petrographic composition and forms of bituminous coal lithotypes in the Upper Carboniferous Formations of the Upper Silesian Coal Basin". Gospodarka Surowcami Mineralnymi 33, n.º 3 (26 de septiembre de 2017): 109–20. http://dx.doi.org/10.1515/gospo-2017-0037.
Texto completoResumen
Abstract Bituminous coal samples were collected from mine excavations of six mines in the Upper Silesian Coal Basin. I n the mentioned mining excavations, the stratighaphic sections, in the form of spot samples, were measured. Based on the macroscopic and microscopic observation, an attempt was made to determine the different lithotypes of coal. Vitrain coal is made of tellinite and collotelinite; the thickness of the layers varies from very thin, thin, medium, to coarse. Durain, which is dominated by macerals from the vitrinite group, is characterized by a darker, almost black color, genetically linked to heavily flooded peat areas, where the deposited phytogenic material is subjected to humification and gelification processes. A brighter durain, with a dark gray color, is dominated by macerals from the inertinite group that originated in the shallower areas of peat bogs where the water level was periodically lowered, which has led to the oxidation of the material deposited in the peat bog. Fusain is another coal component or constituent; it is produced as a result of peat bog fires. It is a charred (not burned) material deposited in the form of layers, lenses, usually with a thickness of up to several millimeters (or, less commonly, several centimeters), or dispersed in the form of shreds in the durain. The petrographic composition is dominated by fusinite and inertodetrinite. Fusain occurs in two varieties: soft (empty cellular spaces) and hard, usually mineralized with carbonates (siderite) or sulphides (pyrite, marcasite). The structure of bituminous coal is, due to its origin, most often laminated and consists of alternating dull and bright layers. Occasionally, such layering can be observed in bright coal, which is the result of layering of large parts of gelified plant materials. When it comes to larger sections of dull coal (without bright coal) in the profile, a solid structure can be observed. Some of the sections in the coal seam profiles show a distorted structure; warped, sometimes shredded layers of vitrain in durain, often containing lenses or shreds of fusain, can be observed.
7
Khan, Mumtaz, Paul B. Cavers, Marguerite Kane y Ken Thompson. "Role of the pigmented seed coat of proso millet (Panicum miliaceumL.) in imbibition, germination and seed persistence". Seed Science Research 7, n.º 1 (marzo de 1997): 21–26. http://dx.doi.org/10.1017/s0960258500003329.
Texto completoResumen
AbstractProso millet (Panicum miliaceumL.) is both a crop and a weed in many parts of the world. The weedy biotypes exhibit a wide range of seed colours, but the strains with the most persistent seeds are distinguished by darker seeds. This paper compares the seed biology of a range of biotypes from Canada and demonstrates that darker seeds have heavier seed coats, imbibe and germinate more slowly, and suffer less imbibition damage (measured as electrolyte leakage). It is concluded that all these attributes contribute to the increased persistence in the soil of the dark-seeded weedy biotypes. Imbibition damage is widely implicated in poor emergence and low vigour of crop seeds, but has not previously been considered in the context of weed seed persistence.
8
Xiong, Mei, Mengli Zhao, Zhen-Xiang Lu y Parthiba Balasubramanian. "Genotypic variation for phenolic compounds in developing and whole seeds, and storage conditions influence visual seed quality of yellow dry bean genotypes". Canadian Journal of Plant Science 100, n.º 3 (1 de junio de 2020): 284–95. http://dx.doi.org/10.1139/cjps-2019-0153.
Texto completoResumen
Seed coat colour is an important determinant of the visual quality of dry beans, as seeds are sold as a dry commodity. Phenolic compounds have a major effect on the colour of bean seeds. The objectives of the study were to determine the changes in phenolic compounds during seed development and in whole seeds of yellow bean genotypes with contrasting seed coat colour, and the effects of storage temperature and duration on seed phenolics and colour. Condensed tannin, phenolic acid, flavonoids, and antioxidant activity were observed as early as 10 d after flowering in the developing seeds of Arikara Yellow, which darken at harvest and during postharvest storage. In contrast, for CDC Sol and AAC Y073 seeds which remain yellow, phenolic compounds and antioxidant activity were consistently low. Seed brightness (L*) and yellow colour (b*) were negatively correlated with phenolic compounds and antioxidant activity, and conversely seed redness (a*) was positively correlated with phenolic compounds, confirming a negative influence of phenolic compounds on seed coat colour. Yellow bean genotypes had low anthocyanin but were high in β-carotene. Storage temperature influenced condensed tannin and seed coat colour, whereas the duration of storage influenced phenolic compounds, antioxidant activity, and seed coat colour. Higher temperatures (20 or 30 °C) and longer storage duration (120 or 180 d) generally resulted in darker seeds with increasing redness compared with seeds stored at 6 °C or for 60 d. AAC Y073 and CDC Sol with improved seed coat colour may increase consumer preference, value, and marketability of yellow beans.
9
Iliushin, Vadim Alexandrovich. "First find of Cadophora antarctica Rodr.-Andrade, Stchigel, Mac Cormack & Cano in the Arctic". Czech Polar Reports 10, n.º 2 (1 de julio de 2020): 147–52. http://dx.doi.org/10.5817/cpr2020-2-11.
Texto completoResumen
Cadophora antarctica Rodr.-Andrade, Stchigel, Mac Cormack & Cano was isolated from spoil tip of coal mine in the Arctic, on the territory of the Svalbard archipelago, and is represented by strain IVA-206. Macro- and micromorphology of the isolate were examined along with partial sequences of Internal transcribed spacer rDNA region (ITS1-5.8S-ITS2) and D1/D2 region of 28S rDNA (LSU). The isolate C. antarctica IVA-206 had a number of features that distinguished it from the strain C. antarctica CBS 143035 from Antarctica. Colonies of Arctic strain had darker pigmentation, ramoconidia and conidia were larger, and the optimal growth temperature was higher. As a result of our study, we first discovered the microfungi C. antarctica Rodr.-Andrade, Stchigel, Mac Cormack & Cano in the Arctic. Our study shows that C. antarctica Rodr.-Andrade, Stchigel, Mac Cormack & Cano is a bipolar species found in both the Arctic and Antarctic region.
10
Thomas, Druml, Grilz-Seger Gertrud, Horna Michaela y Brem Gottfried. "Discriminant analysis of colour measurements reveals allele dosage effect of ASIP/MC1R in bay horses". Czech Journal of Animal Science 63, No. 9 (31 de agosto de 2018): 347–55. http://dx.doi.org/10.17221/105/2017-cjas.
Texto completoResumen
Considering the variability of bay coat colour, we aimed to investigate the association of different shades of bay with ASIP and MC1R genotype combinations and we studied the discrimination between the bay and black coat colour. We phenotypically characterized coat colour using a spectrophotometer. The measurements were based upon international standards as defined by the CIE L*a*b* colour system and we phenotyped five different body parts (neck, armpit area, shoulder, belly, croup) of 43 bay and 14 black horses kept under standardized conditions. From the five measuring points a stepwise discriminant analysis revealed that chromacity and luminescence of armpit area and luminescence of the neck were the most important traits to differentiate between black and bay horses, whereas it was shown that the red colour spectrum of neck, luminescence of the neck, and luminescence of the armpit area grouped bay horses according to their ASIP and MC1R genotype combinations. Within the group of bay horses the analyses identified a single ASIP/MC1R genotype combination (A/a E/E) where colour variables differed significantly from the three remaining genotype groups. A/a E/E horses were characterized in all body parts except in the armpit region by significant darker shades (lower luminescence, less chromacity). Regarding classifications of coat colour, we found in the significant cluster of A/a E/E horses the coat colour categories seal brown and dark (mahogany) bay. Overall, we were able to show that the characterization of equine coat colour based upon international standards as defined by the CIE L*a*b* colour system represents a valuable tool for a precise description of colour variation and association analyses.
11
Sandoval Salinas, M. L., R. M. Barquez, E. M. Colombo y J. D. Sandoval. "Intra-specific pelage color variation in a South American small rodent species". Brazilian Journal of Biology 77, n.º 1 (marzo de 2017): 1–11. http://dx.doi.org/10.1590/1519-6984.00615.
Texto completoResumen
Abstract Intra-specific color variation is often underestimated by researchers, and among mammals, intra-specific differences in coloration are poorly documented for most species. The main goal of this study was to apply an objective color measurement methodology to the study of a specific problem: the detection, if any, of patterns of changes in the fur color of specimens of Akodon budini in relation to biological (i.e., sex) and environmental (i.e., season) variables. We hypothesize that coat color will be more homogeneous in males than in females and that coat color will be darker in winter than in summer, the latter being orange. We measured the pelage color on five points over the dorsal surface of 26 A. budini museum specimens using a spectroradiometer and a diffuse illumination cabin. We used Principal Component Analysis to describe the association between the color variables, sex and season, and each of the observations. We then used general linear models of Analysis of Variance to examine relationships between color data, season, and sex. The results clearly confirm the hypothesis related to seasonal coat color change but do not directly confirm the hypothesis related to changes in coat color in relation to sex, and we show the complexity of the studied pattern. In conclusion, undoubtedly, the studied variables should accordingly be considered when studying the coloration of specimens for characterization, identification and discrimination of different taxonomic units based on color.
12
Beketov, Sergey V., Irina E. Chernova, Yuriy I. Rozhkov, Lidiya V. Toporova y Konstantin S. Karpov. "Darkening of the color as а marker sign of reduced reproductive ability of female sable (martes zibellina) and mink (neovison vison)". Ecological genetics 17, n.º 3 (26 de septiembre de 2019): 75–86. http://dx.doi.org/10.17816/ecogen17375-86.
Texto completoResumen
Based on the materials of 23 fur-bearing animal farms of the Russia for different periods of years, a comparative assessment of the reproductive capacity of sable and mink females of standard breeds (wild type) has been carried out. It was established that during intrabreeding differentiation according to the overall color of the hair coat (almost black, black-brown, dark brown and chestnut), the lowest reproduction level is characterized by darker females of sable, which are a significant increase in the number of them, mated with male, but not given offspring (barren females). According to the results of interbreed comparisons of sables and minks, parallelism was found in the variability of the reproductive capacity of females, which is manifested in the fact that, in contrast to relatively light animals, animals that are dark in color are characterized by a greater number of barren females and low fecundity.
13
Prayaga, K. C., N. J. Corbet, D. J. Johnston, M. L. Wolcott, G. Fordyce y H. M. Burrow. "Genetics of adaptive traits in heifers and their relationship to growth, pubertal and carcass traits in two tropical beef cattle genotypes". Animal Production Science 49, n.º 6 (2009): 413. http://dx.doi.org/10.1071/ea08247.
Texto completoResumen
Genetic analyses of tropical adaptive traits were conducted for two tropically adapted genotypes, Brahman (BRAH) and Tropical Composite (TCOMP). Traits included tick scores (TICK), faecal egg counts (EPG), buffalo fly-lesion scores (FLY), rectal temperatures under hot conditions (TEMP), coat scores (COAT), coat colour on a light to dark scale (COLOUR), navel scores (NAVEL) and temperament measured as flight time (FT). The data comprised adaptive measures recorded at specific times on 2071 heifers comprising 966 BRAH and 1105 TCOMP. The genetic correlations of these adaptive traits with heifer growth, scanned carcass, pubertal measures and steer growth and carcass traits were estimated. BRAH recorded significantly (P < 0.05) lower TICK, EPG, FLY and TEMP than did TCOMP. BRAH also had significantly sleeker coats, lighter coat colour, more pendulous navels and more docile temperament than did TCOMP. The heritability of TICK and FLY was low (<20%), that of EPG, TEMP, NAVEL and FT was moderate (20–50%) and that of COAT and COLOUR high (>50%). In general, phenotypic correlations between these adaptive traits were low and genetic correlations were non-significant, implying trait independence. Genetic correlations between EPG and weight traits (0.29 to 0.44) indicated a positive relationship, implying no deleterious effect of worms on the growth at a genetic level, especially in TCOMP. The negative genetic correlations between COAT and body-condition score across genotypes (–0.33 to –0.48) indicated genetic advantage of sleek coats in tropics. A positive genetic correlation between COAT and the age at the first-observed corpus luteum (0.73) in BRAH indicated that BRAH with sleeker coats were genetically early maturing. Further, sleeker coats were genetically indicative of lower weights and lower fat cover at puberty in BRAH. The scanned fat measures at rump and rib sites for feedlot steers showed strong genetic correlation (0.50–0.58) with heifer TEMP, indicating genetically fatter animals had genetically lower heat tolerance. In BRAH, a positive genetic association between heifer COLOUR and scanned fat measures in steers (0.50–0.54) implied increased fatness in genetically darker animals. Further, in BRAH, a strong negative genetic correlation (–0.97) was observed between steer retail beef yield and heifer TEMP, indicating a favourable genetic association. In general, genetic correlations between adaptive traits and other economic traits were genotype specific. Further, it can be concluded that selection for productive and pubertal traits in tropical beef cattle genotypes would not adversely affect their tropical adaptability.
14
Deng, Weidong, Yuwen Tan, Xinyu Wang, Dongmei Xi, Yiduo He, Shuli Yang, Huaming Mao y Shizheng Gao. "Molecular cloning, sequence characteristics, and polymorphism analyses of the tyrosinase-related protein 2 / DOPAchrome tautomerase gene of black-boned sheep (Ovis aries)". Genome 52, n.º 12 (diciembre de 2009): 1001–11. http://dx.doi.org/10.1139/g09-078.
Texto completoResumen
Tyrosinase-related protein 2 (TYRP2) plays a pivotal role in the biosynthesis of eumelanin. Black-boned sheep have excessive melanin and eumelanin, resulting in dark (black) muscles and organs. This study was designed to investigate the effects of variants of the TYRP2 gene on black traits and coat colour of black-boned sheep. Melanin traits were measured in three populations of sheep (Nanping black-boned, Nanping normal, and Romney Marsh) and compared in this study. From the TYRP2 cDNA, all 8 exons and their flanking regions were amplified and characterized. Fifteen single nucleotide polymorphisms (SNPs) were identified in the exons and their flanking regions. Five exonic polymorphic sites, including two synonymous (c.93T>G and c.1140C>T) and three non-synonymous mutations (c.163C>T (p.R55W), c.605G>A (p.R202H), and c.1141A>G (p.T381A)), were retrieved. PCR-RFLP analysis of c.605G>A showed that the frequencies of allele G in the Nanping black-boned, Nanping normal, and Romney Marsh sheep were 0.632, 0.603, and 0.886, respectively. Sheep with the GG genotype had significantly (P < 0.05) lower tyrosinase activity, alkali-soluble melanin content, and ratio of eumelanin : total melanin than sheep with GA and AA genotypes when measured across all investigated samples but not when samples within each population of sheep were compared. However, there was no association of TYRP2 genotype at a single SNP position with coat colour across populations. Nonetheless, the two breeds with higher overall tyrosinase activity did produce darker and more varied coat colours than the breed with lower tyrosinase activity.
15
Getinet, A. y G. Rakow. "Repression of seed coat pigmentation in Ethiopian mustard". Canadian Journal of Plant Science 77, n.º 4 (1 de octubre de 1997): 501–5. http://dx.doi.org/10.4141/p96-152.
Texto completoResumen
The inheritance of seed colour in Brassica carinata A. Braun was investigated in backcross and F2 generations derived from two crosses between the brown seeded cultivar S-67 and two, true breeding, yellow seeded lines, PGRC/E 21164 and PGRC/E 21224 of the Plant Gene Resources Centre of Ethiopia. F1 seed was identical in colour to self-pollinated seed borne on the respective brown and yellow seeded parents indicating maternal control of seed colour in B. carinata. F1 plants of reciprocal crosses produced yellow seed that was somewhat darker than that of the yellow-seeded parent indicating incomplete dominance of yellow over brown. Backcross F1 plants, derived from the backcross to the brown parent, segregated brown and light yellow-brown/yellow seeded plants in a 1:1 ratio, while backcrosses to both yellow seeded parents produced only light yellow-brown/yellow seeded plants. The F2 generation segregated brown and light yellow-brown/yellow seeded plants in a 1:3 ratio. These results are in contrast to seed colour inheritance pattern observed in other Brassica species, where brown seed colour was fully or partially dominant over yellow. The apparent dominance of the absence of a gene product in yellow seed over its presence in brown seed, was explained by the presence of a dominant repressor gene (Rp) in yellow seed which inhibits the expression of seed coat pigment synthesis genes. The repressor gene is absent in brown seeded plants. The significance of this finding in relation to the development of yellow seeded lines in other Brassica species is discussed. Key words: Brassica carinata, seed colour inheritance, repressor
16
Deol, M. S., Gillian M. Truslove y Anne McLaren. "Genetic activity at the albino locus in Cattanach's insertion in the mouse". Development 96, n.º 1 (1 de julio de 1986): 295–302. http://dx.doi.org/10.1242/dev.96.1.295.
Texto completoResumen
Cattanach's insertion (Is(In7;X)1Ct or XCt) includes the normal allele at the albino locus (c+), which is subject to inactivation of the X chromosome carrying it, so that XCtX; c c mice have albino and pigmented patches. The X-autosome translocation T(X;16)16H or XT16H leads to preferential inactivation of the other X chromosome in female cells, so that XCtXT16H; c c mice are almost entirely white. However, they grow darker with age, as if reversal of inactivation of the c+ allele were taking place in increasing numbers of melanocytes. To test whether this is dependent only on age or whether it is related to the number of times the animal has moulted, hair was repeatedly plucked from selected areas at the early telogen stage when the follicles are also removed, assuming that the melanocytes or melanoblasts in that region of the skin would be forced to undergo further divisions to colonize the new follicles. The plucked areas grew darker at the same rate as the rest of the coat, suggesting that the progressive reversal of inactivation is dependent only on age. As direct examination of melanocytes in the follicles is difficult, they were examined in the choroid and the retinal pigment epithelium (RPE) of the eye. The frequency of the pigmented cells was lower in the choroid than in the RPE. Since the melanocytes in these structures are different in origin as well as in physical characteristics, it appears that cell type influences either reversal of inactivation, or the frequency with which the influence of the X chromosome extends to the albino locus.
17
Baliarti, Endang, Teguh Dwi Putra, Panjono Panjono, Sigit Bintara, Dyah Tri Widayati y Bramada Putra. "Characteristics of skin coat as well as the physiological status of F1 crossing Bali (Bos Sondaicus) x Angus (Bos Taurus) for early identification of adaptability in tropical environment". MOJ Ecology & Environmental Sciences 6, n.º 3 (28 de mayo de 2021): 82–86. http://dx.doi.org/10.15406/mojes.2021.06.00219.
Texto completoResumen
Characteristics of skin and hair color in cattle, as well as the number of skin follicles, have an essential role in the process of adapting to the ambient temperature and humidity. Bali cattle (Bos Sondaicus) is an indigenous Indonesian cattle that is a tropical climate, has the characteristics of the light hair color crossing with Black Angus (Bos Taurus) from different species, subtropical climate. Objective: To know the changes in the skin and hair color characteristics of F1 crossing of Bos Sondaicus with Angus (Bos Taurus), and whether it affects its adaptability to the tropical environment. Methods: Twenty of F1 Angus x Bali cross cattle were studied for their characteristics of skin and hair color, a number of skin follicles as well as physiological status for early identification of adaptability in a tropical environment. Hair and skin color measured by the value of the RGB (Red, Green, Blue) method. Completely Randomized Design (CRD) was done to distinguish RGB values and the physiological status between crossed compare to local breed. Results: The results showed that the RGB values of crossed were significantly lower (P<0.05), had meant that darker and had fewer hair follicles (P<0.05) (15.18±2.24 vs. 21.38±4.33/mm2) which caused the skin surface temperature was higher (P<0.05)(35.41±1.14 vs. 34.31±2.27˚C). Although during the day, they had a higher physiological status (P<0.05) but still in the normal range. Conclusion: It concluded that although the skin and hair color became markedly darker, they still can adapt to the tropical environment, shown from body temperature, respiration rate, and pulses, as the gold standard for measures cattle's tolerance to environmental conditions.
18
Pennisi, David, Josephine Bowles, Andras Nagy, George Muscat y Peter Koopman. "Mice Null for Sox18 Are Viable and Display a Mild Coat Defect". Molecular and Cellular Biology 20, n.º 24 (15 de diciembre de 2000): 9331–36. http://dx.doi.org/10.1128/mcb.20.24.9331-9336.2000.
Texto completoResumen
ABSTRACT We have previously shown that Sox18 is expressed in developing vascular endothelium and hair follicles during mouse embryogenesis and that point mutations in Sox18 are the underlying cause of cardiovascular and hair follicle defects inragged (Ra) mice. Here we describe the analysis of Sox18 −/− mice produced by gene targeting. Despite the profound defects seen in Ra mice,Sox18 −/− mice have no obvious cardiovascular defects and only a mild coat defect with a reduced proportion of zigzag hairs. A reduction in the amount of pheomelanin pigmentation in hair shafts was also observed; later-forming hair follicles showed a reduced subapical pheomelanin band, giving Sox18 −/−mice a slightly darker appearance than Sox18 +/+and Sox18 +/− siblings.Sox18 −/− mice are viable and fertile and show no difference in the ability to thrive relative to littermates. Because of the mild effect of the mutation on the phenotype ofSox18 −/− mice, we conclude that the semidominant nature of the Ra mutations is due to atrans-dominant negative effect mediated by the mutant SOX18 proteins rather than haploinsufficiency as has been observed for otherSOX genes. Due to the similarity of SOX18 to other subgroup F SOX proteins, SOX7 and −17, and the overlap in expression of these genes, functional redundancy amongst these SOX proteins could also account for the mild phenotype of Sox18 −/−mice.
19
Borchardt, Jakob, Konstantin Gerilowski, Sven Krautwurst, Heinrich Bovensmann, Andrew K. Thorpe, David R. Thompson, Christian Frankenberg, Charles E. Miller, Riley M. Duren y John Philip Burrows. "Detection and quantification of CH<sub>4</sub> plumes using the WFM-DOAS retrieval on AVIRIS-NG hyperspectral data". Atmospheric Measurement Techniques 14, n.º 2 (18 de febrero de 2021): 1267–91. http://dx.doi.org/10.5194/amt-14-1267-2021.
Texto completoResumen
Abstract. Methane is the second most important anthropogenic greenhouse gas in the Earth's atmosphere. To effectively reduce these emissions, a good knowledge of source locations and strengths is required. Airborne remote sensing instruments such as the Airborne Visible InfraRed Imaging Spectrometer – Next Generation (AVIRIS-NG) with meter-scale imaging capabilities are able to yield information about the locations and magnitudes of methane sources. In this study, we successfully applied the weighting function modified differential optical absorption spectroscopy (WFM-DOAS) algorithm to AVIRIS-NG data measured in Canada and the Four Corners region. The WFM-DOAS retrieval is conceptually located between the statistical matched filter (MF) and the optimal-estimation-based iterative maximum a posteriori DOAS (IMAP-DOAS) retrieval algorithm, both of which were already applied successfully to AVIRIS-NG data. The WFM-DOAS algorithm is based on a first order Taylor series approximation of the Lambert–Beer law using only one precalculated radiative transfer calculation per scene. This yields the fast quantitative processing of large data sets. We detected several methane plumes in the AVIRIS-NG images recorded during the Arctic-Boreal Vulnerability Experiment (ABoVE) Airborne Campaign and successfully retrieved a coal mine ventilation shaft plume observed during the Four Corners measurement campaign. The comparison between IMAP-DOAS, MF, and WFM-DOAS showed good agreement for the coal mine ventilation shaft plume. An additional comparison between MF and WFM-DOAS for a subset of plumes showed good agreement for one plume and some differences for the others. For five plumes, the emissions were estimated using a simple cross-sectional flux method. The retrieved fluxes originated from well pads, cold vents, and a coal mine ventilation shaft and ranged between (155 ± 71) kg (CH4) h−1 and (1220 ± 450) kg (CH4) h−1. The wind velocity was a significant source of uncertainty in all plumes, followed by the single pixel retrieval noise and the uncertainty due to atmospheric variability. The noise of the retrieved CH4 imagery over bright surfaces (>1 µW cm−2 nm−1 sr−1 at 2140 nm) was typically ±2.3 % of the background total column of CH4 when fitting strong absorption lines around 2300 nm but could reach over ±5 % for darker surfaces (< 0.3 µW cm−2 nm−1 sr−1 at 2140 nm). Additionally, a worst case large-scale bias due to the assumptions made in the WFM-DOAS retrieval was estimated to be ±5.4 %. Radiance and fit quality filters were implemented to exclude the most uncertain results from further analysis mostly due to either dark surfaces or surfaces where the surface spectral reflection structures are similar to CH4 absorption features at the spectral resolution of the AVIRIS-NG instrument.
20
Zang, Jian Bing, Jing Lu, Yan Hui Wang, X. H. Qi y Yun Gang Yuan. "Ti Coating of Nanocrystalline Diamond by Atomic Layer Deposition". Key Engineering Materials 304-305 (febrero de 2006): 48–51. http://dx.doi.org/10.4028/www.scientific.net/kem.304-305.48.
Texto completoResumen
Nanocrystalline diamond compact possesses not only the advantageous performance of polycrystalline diamond but also the high strength and the high toughness of nano-ceramics. However, single-phase nanocrystalline diamond compact is very difficult to sinter because of a huge amount of oxygen-containing and nitrogen-containing functional groups absorbed on the surface of nanocrystalline diamond. In this paper, atomic layer deposition (ALD) method has been used to coat nanocrystalline diamond with titanium, which will promote the bonding of nanocrystalline diamond as the bond in polycrystalline diamond. In vacuum, the H2 and TiCl4 reactants were employed alternately in an ABAB… binary reaction sequence to achieve Ti layer, which reacted with diamond matrix and formed TiC in the coating, realizing strong chemical bonding between the coating and the diamond. X-ray diffraction (XRD) and transmission electron microscopy (TEM) were utilized to study the structure and the morphology of the coating. The results confirmed the formation of titanium carbide at the depositing temperature 500°C. The darker spots and strips observed on nanocrystalline diamond particles by TEM were proved to be TiC and the nucleation and subsequent growth of TiC preferentially occurred in the defects as twin zones and dislocation areas on diamond surfaces.
21
Burchill, S. A., S. Ito y A. J. Thody. "Effects of melanocyte-stimulating hormone on tyrosinase expression and melanin synthesis in hair follicular melanocytes of the mouse". Journal of Endocrinology 137, n.º 2 (mayo de 1993): 189–95. http://dx.doi.org/10.1677/joe.0.1370189.
Texto completoResumen
ABSTRACT Tyrosinase mRNA, synthesis and activity were measured in the skin during the first 2 weeks of life of C3H-HeAvy mice. Tyrosinase mRNA levels were found to peak on days 3–4 and were followed by increases in tyrosinase synthesis and activity which peaked on days 6–7 and 7–8 respectively. These changes in tyrosinase expression were presumably associated with the growth of the first coat of hair that in neonatal C3H-HeAvy mice is yellow in colour as a result of the increased proportion of phaeomelanin. By the time hair growth had ceased there was no expression of tyrosinase at both mRNA and protein levels. Daily administration of α-melanocyte stimulating hormone (α-MSH) enhanced the expression of tyrosinase mRNA transcripts, tyrosinase synthesis and activity. The increase in tyrosinase activity paralleled the change in the amount of tyrosinase, suggesting that the primary action of α-MSH is to stimulate new synthesis of the enzyme. This induction of tyrosinase was associated with the growth of hair that was darker in colour than that of the controls and contained an increased proportion of eumelanin. This increase in eumelanin reflected a decrease in phaeomelanin content. It was concluded that, through its actions on the enzyme tyrosinase, α-MSH is able to switch the synthesis of phaeomelanin to that of eumelanin in hair follicular melanocytes. Journal of Endocrinology (1993) 137, 189–195
22
Nigenda-Morales, Sergio F., Ryan J. Harrigan y Robert K. Wayne. "Playing by the rules? Phenotypic adaptation to temperate environments in an American marsupial". PeerJ 6 (27 de marzo de 2018): e4512. http://dx.doi.org/10.7717/peerj.4512.
Texto completoResumen
Phenotypic variation along environmental gradients can provide evidence suggesting local adaptation has shaped observed morphological disparities. These differences, in traits such as body and extremity size, as well as skin and coat pigmentation, may affect the overall fitness of individuals in their environments. The Virginia opossum (Didelphis virginiana) is a marsupial that shows phenotypic variation across its range, one that has recently expanded into temperate environments. It is unknown, however, whether the variation observed in the species fits adaptive ecogeographic patterns, or if phenotypic change is associated with any environmental factors. Using phenotypic measurements of over 300 museum specimens of Virginia opossum, collected throughout its distribution range, we applied regression analysis to determine if phenotypes change along a latitudinal gradient. Then, using predictors from remote-sensing databases and a random forest algorithm, we tested environmental models to find the most important variables driving the phenotypic variation. We found that despite the recent expansion into temperate environments, the phenotypic variation in the Virginia opossum follows a latitudinal gradient fitting three adaptive ecogeographic patterns codified under Bergmann’s, Allen’s and Gloger’s rules. Temperature seasonality was an important predictor of body size variation, with larger opossums occurring at high latitudes with more seasonal environments. Annual mean temperature predicted important variation in extremity size, with smaller extremities found in northern populations. Finally, we found that precipitation and temperature seasonality as well as low temperatures were strong environmental predictors of skin and coat pigmentation variation; darker opossums are distributed at low latitudes in warmer environments with higher precipitation seasonality. These results indicate that the adaptive mechanisms underlying the variation in body size, extremity size and pigmentation are related to the resource seasonality, heat conservation, and pathogen-resistance hypotheses, respectively. Our findings suggest that marsupials may be highly susceptible to environmental changes, and in the case of the Virginia opossum, the drastic phenotypic evolution in northern populations may have arisen rapidly, facilitating the colonization of seasonal and colder habitats of temperate North America.
23
Caro, Tim, Kasey Brockelsby, Annie Ferrari, Manisha Koneru, Konatsu Ono, Edward Touche y Theodore Stankowich. "The evolution of primate coloration revisited". Behavioral Ecology 32, n.º 4 (1 de julio de 2021): 555–67. http://dx.doi.org/10.1093/beheco/arab029.
Texto completoResumen
Abstract Primates are noted for their varied and complex pelage and bare skin coloration but the significance of this diverse coloration remains opaque. Using new updated information, novel scoring of coat and skin coloration, and controlling for shared ancestry, we reexamined and extended findings from previous studies across the whole order and the five major clades within it. Across primates, we found (i) direct and indirect evidence for pelage coloration being driven by protective coloration strategies including background matching, countershading, disruptive coloration, and aposematism, (ii) diurnal primates being more colorful, and (iii) the possibility that pelage color diversity is negatively associated with female trichromatic vision; while (iv) reaffirming avoidance of hybridization driving head coloration in males, (v) darker species living in warm, humid conditions (Gloger’s rule), and (vi) advertising to multiple mating partners favoring red genitalia in females. Nonetheless, the importance of these drivers varies greatly across clades. In strepsirrhines and cercopithecoids, countershading is important; greater color diversity may be important for conspecific signaling in more diurnal and social strepsirrhines; lack of female color vision may be associated with colorful strepsirrhines and platyrrhines; whereas cercopithecoids obey Gloger’s rule. Haplorrhines show background matching, aposematism, character displacement, and red female genitalia where several mating partners are available. Our findings emphasize several evolutionary drivers of coloration in this extraordinarily colorful order. Throughout, we used coarse but rigorous measures of coloration, and our ability to replicate findings from earlier studies opens up opportunities for classifying coloration of large numbers of species at a macroevolutionary scale.
24
Miah, MAQ, MA Awal, MM Rahman y MS Islam. "EFFECTS OF LONG TERM ADMINISTRATION OF GENTAMICIN ON CLINICO-PATHOLOGICAL PARAMETERS IN SWISS ALBINO MICE". Bangladesh Journal of Veterinary Medicine 3, n.º 1 (23 de julio de 2012): 87–91. http://dx.doi.org/10.3329/bjvm.v3i1.11393.
Texto completoResumen
The effects of long-term intramuscular injection of gentamicin (Gentin® inj., Opsonin, Bangladesh Ltd.) were studied clinicopathologically on twenty 60 day-old Swiss Albino mice of either sex for 42 days during January to March 2002. All the mice were grouped into four, each consisting of one male and four female mice, of which one group (group A) served as control without giving any treatment while groups B, C and D received recommended (50 mg / kg), medium (75 mg / kg) and double the recommended (100 mg / kg) doses of gentamicin intramuscularly daily for 42 days. All the treated mice produced mild to severe clinical signs, i.e., roughness of the body coat, dullness, depression, anorexia and weakness. At recommended and medium doses the offspring were apparently normal but at double the recommended dose, 10% offspring were died and others were weak and emaciated. No significant gross change was found in lungs, spleen and heart of all the treated groups but the kidney was found soft, flabby and enlarged and the heart was found darker, congested with necrotic foci on the surface. Histopathological changes showed chronic interstitial nephritis in groups B and C following recommended (50 mg / kg) and medium (75 mg / kg) doses while severe glomerulonephritis was observed following double the recommended dose (100 mg / kg) of gentamicin. In liver, histopathological study showed coagulation necrosis following recommended dose, whereas, karyorrhoexis and tissue regeneration were found following medium and double the recommended doses. In lungs, haemorrhage and thickening of interstitial tissues were observed following double the recommended dose of gentamicin in mice. Thus long term administration of higher dose of gentamicin is detrimental to the vital organs.
25
Hamed, K., W. Menzel, M. E. Mohamed, K. A. Bakheet y S. Winter. "First Report of Garlic common latent virus Infecting Garlic in Sudan". Plant Disease 97, n.º 4 (abril de 2013): 562. http://dx.doi.org/10.1094/pdis-11-12-1018-pdn.
Texto completoResumen
Garlic (Allium sativum L.) is one of the most important vegetable field crops in Sudan, cultivated on an area of more than 6,000 ha with a total yield of 27,000 t in 2010 (faostat.fao.org). As part of a project which started in 2010 to improve the garlic production in Sudan, samples from local varieties showing severe mosaic and/or mottling were collected in winter 2011 from the main production areas in River Nile State, Northern State, and Darfur State. The plant material used for garlic production came from Sudan and was not imported. Because no reliable data were available on which viruses occur in garlic in Sudan, specific tests were initially omitted. In order to get an overview of the viruses present, dsRNA was prepared of a mixed leaf sample (12 leaves of different samples). This resulted in a high molecular weight dsRNA of approximately 9 kbp that served as template for a random RT-PCR followed by cloning and sequencing (3). Three identical clones originating from one PCR product covering the C-terminal part of the coat protein to the N-terminal part of the nucleic acid binding protein showed the highest sequence similarity to Garlic common latent virus (GarCLV). The nucleotide sequence identities of the 554-bp insert range from 85% to an isolate from India (Accession No. FJ154841) up to 97% to a GarCLV isolate from The Netherlands (AB004804), identifying the virus as a Sudanese isolate of GarCLV, one of the most common garlic infecting viruses. GarCLV belongs to the genus Carlavirus (1) and has previously been reported from Asia, Europe, and South America ( http://sdb.im.ac.cn/vide/descr352.htm ). In order to confirm these results, a double antibody sandwich (DAS)-ELISA was performed with six individual garlic samples in which five samples showed a clear reaction with a GarCLV specific antiserum (AS-0230, DSMZ, Germany). The occurrence of GarCLV could be further confirmed for the ELISA positive samples by a specific RT-PCR using the primers published by Majumder and Baranwal (2). Fragments of the expected size were obtained for all five samples. In addition, one of the positive samples was examined by electron microscopy (Dr. K. Richert-Pöggeler, JKI Braunschweig); filamentous flexous particles typical for carlaviruses could be observed. The random RT-PCR sequence obtained in this study has been submitted to GenBank (KC013030). To our knowledge, this is the first report of GarCLV in garlic in Sudan and Africa. The impact of GarCLV on garlic production in Sudan needs to be evaluated, but the awareness of the occurrence of the virus and the availability of a reliable diagnostic tool will help to select virus-free propagation material. This will form the basis for a sustainable garlic production. References: (1) A. M. Q. King et al. Virus Taxonomy 924, 2012. (2) S. Majumder and V. K. Baranwal. Plant Dis. 93:106, 2009. (3) W. Menzel et al. Arch. Virol. 154:1343, 2009.
26
Teubner, Gunther. "The Law before its law: Franz Kafka on the (Im)possibility of Law's Self-reflection". German Law Journal 14, n.º 2 (1 de febrero de 2013): 405–22. http://dx.doi.org/10.1017/s2071832200001851.
Texto completoResumen
Before the Law stands a doorkeeper. A man from the countryside comes up to the door and requests admittance to the Law. But the doorkeeper says that he can't grant him admittance now. The man thinks it over and then asks if he'll be allowed to enter later. “It's possible” says the doorkeeper, “but not now.” Since the gate to the Law stands open as always, and the doorkeeper steps aside, the man bends down to look through the gate into the interior. When the doorkeeper sees this, he laughs and says: “If you're so drawn to it, go ahead and try to enter, even though I've forbidden it. But bear this in mind: I'm powerful. And I'm only the lowest doorkeeper. From hall to hall, however, stand doorkeepers each more powerful than the one before. The mere sight of the third is more than even I can bear.” The man from the country has not anticipated such difficulties; the Law should be accessible to anyone at any time, he thinks, but as he now examines the doorkeeper in his fur coat more closely, his large, sharply pointed nose, his long, thin, blank tartar's beard, he decides he would prefer to wait until he receives permission to enter. And the doorkeeper gives him a stool and lets him sit down at the side of the door. He sits there for days and years. He asks time and again to be admitted and wearies the doorkeeper with his entreaties. The doorkeeper often conducts brief interrogations, inquiring about his home and many other matters, but he asks such questions indifferently, as great men do, and in the end he always tells him he still can't admit him. The man, who has equipped himself well for the journey, uses everything he has, no matter how valuable, to bribe the doorkeeper. And the doorkeeper accepts everything, but as he does so he says: “I'm taking this just so you won't think you've neglected something.” Over the many years, the man observes the doorkeeper almost incessantly. He forgets the other doorkeepers and this first one seems to him the only obstacle to his admittance to the Law. He curses his unhappy fate, loudly during the first years, later, as he grows older, merely grumbling to himself. He turns childish, and since he has come to know even the fleas in the doorkeeper's collar over his years of study, he asks the fleas too to help him change the doorkeeper's mind. Finally his eyes grow dim and he no longer knows whether it's really getting darker around him or if his eyes are merely deceiving him. And yet in the darkness he now sees a radiance that streams forth inextinguishably from the door of the Law. He doesn't have much longer to live now. Before he dies, everything he has experienced over the years coalesces in his mind into a single question he has never asked the doorkeeper. He motions to him, since he can no longer straighten his stiffening body. The doorkeeper hat to bend down to him, for the difference in size between them has altered greatly to the man's disadvantage. “What do you want to know now,” asks the doorkeeper, “you're insatiable.” “Everyone strives to reach the Law,” says the man, “how does it happen, then, that in all these years no one but me has requested admittance.” The doorkeeper sees that the man in nearing his end, and in order to reach his failing hearing, he roars at him: “No one else could gain admittance here, because this entrance was meant solely for you. I'm going to go and shut it now.”
27
Trigo, Beatriz B., Adam T. H. Utsunomiya, Alvaro A. A. D. Fortunato, Marco Milanesi, Rafaela B. P. Torrecilha, Harrison Lamb, Loan Nguyen et al. "Variants at the ASIP locus contribute to coat color darkening in Nellore cattle". Genetics Selection Evolution 53, n.º 1 (28 de abril de 2021). http://dx.doi.org/10.1186/s12711-021-00633-2.
Texto completoResumen
Abstract Background Nellore cattle (Bos indicus) are well-known for their adaptation to warm and humid environments. Hair length and coat color may impact heat tolerance. The Nellore breed has been strongly selected for white coat, but bulls generally exhibit darker hair ranging from light grey to black on the head, neck, hump, and knees. Given the potential contribution of coat color variation to the adaptation of cattle populations to tropical and sub-tropical environments, our aim was to map positional and functional candidate genetic variants associated with darkness of hair coat (DHC) in Nellore bulls. Results We performed a genome-wide association study (GWAS) for DHC using data from 432 Nellore bulls that were genotyped for more than 777 k single nucleotide polymorphism (SNP) markers. A single major association signal was detected in the vicinity of the agouti signaling protein gene (ASIP). The analysis of whole-genome sequence (WGS) data from 21 bulls revealed functional variants that are associated with DHC, including a structural rearrangement involving ASIP (ASIP-SV1). We further characterized this structural variant using Oxford Nanopore sequencing data from 13 Australian Brahman heifers, which share ancestry with Nellore cattle; we found that this variant originates from a 1155-bp deletion followed by an insertion of a transposable element of more than 150 bp that may impact the recruitment of ASIP non-coding exons. Conclusions Our results indicate that the variant ASIP sequence causes darker coat pigmentation on specific parts of the body, most likely through a decreased expression of ASIP and consequently an increased production of eumelanin.
28
de Almeida, Caléo Panhoca, Isabella Laporte Santos, Jean Fausto de Carvalho Paulino, Caio Cesar Ferrari Barbosa, Cássia Cristina Augusto Pereira, Cassia Regina Limonta Carvalho, Gabriel de Moraes Cunha Gonçalves et al. "Genome-wide association mapping reveals new loci associated with light-colored seed coat at harvest and slow darkening in carioca beans". BMC Plant Biology 21, n.º 1 (20 de julio de 2021). http://dx.doi.org/10.1186/s12870-021-03122-2.
Texto completoResumen
Abstract Background Common bean (Phaseolus vulgaris L.) is a legume whose grain can be stored for months, a common practice among Brazilian growers. Over time, seed coats become darker and harder to cook, traits that are undesirable to consumers, who associate darker-colored beans with greater age. Like commercial pinto and cranberry bean varieties, carioca beans that have darker seeds at harvest time and after storage are subject to decreased market values. Results The goal of our study was to identify the genetic control associated with lightness of seed coat color at harvest (HL) and with tolerance to post-harvest seed coat darkening (PHD) by a genome-wide association study. For that purpose, a carioca diversity panel previously validated for association mapping studies was used with 138 genotypes and 1,516 high-quality SNPs. The panel was evaluated in two environments using a colorimeter and the CIELAB scale. Shelf storage for 30 days had the most expressive results and the L* (luminosity) parameter led to the greatest discrimination of genotypes. Three QTL were identified for HL, two on chromosome Pv04 and one on Pv10. Regarding PHD, results showed that genetic control differs for L* after 30 days and for the ΔL* (final L*—initial L*); only ΔL* was able to properly express the PHD trait. Four phenotypic classes were proposed, and five QTL were identified through six significant SNPs. Conclusions Lightness of seed coat color at harvest showed an oligogenic inheritance corroborated by moderate broad-sense heritability and high genotypic correlation among the experiments. Only three QTL were significant for this trait – two were mapped on Pv04 and one on Pv10. Considering the ΔL, six QTL were mapped on four different chromosomes for PHD. The same HL QTL at the beginning of Pv10 was also associated with ΔL* and could be used as a tool in marker-assisted selection. Several candidate genes were identified and may be useful to accelerate the genetic breeding process.
29
Grilz-Seger, Gertrud, Matjaž Mesarič, Gottfried Brem y Marko Cotman. "CHARACTERISATION OF COAT COLOUR IN THE SLOVENIAN POSAVJE HORSE". SLOVENIAN VETERINARY RESEARCH 58, n.º 2 (30 de junio de 2021). http://dx.doi.org/10.26873/svr-1091-2020.
Texto completoResumen
Different approaches and classification systems have been established to describe equine coat colour, which varies between breeds and countries. In the present study, we first characterised the coat colour variability in the Slovenian Posavje Horse applying colour spectrophotometry following the CIE L*a*b system. As derived from the classification system of Sponenberg (light bay, bay, mahogany bay, brown and seal brown), the phenotype categories could be confirmed by spectrophotometric data. Furthermore, L*a*b values revealed comparable high phenotypic variability of bay coat colour in the Posavje breed, and the darker shades of bay coat colour were associated with the ASIP and MC1R genotype combination A/a E/E. CIE L*a*b colour spectrophotometry represents an effective tool to characterise and quantify coat colour in horses, especially in chestnut horses, for which the underlying genetic background of coat colour variation remains unknown.Key words: Posavje Horse; MC1R; ASIP; coat colour; spectrophotometry; CIE L*a*b KARAKTERIZACIJA BARVE DLAKE PRI POSAVSKEM KONJU Izvleček: Za opis barv konj se uporabljajo različni pristopi in klasifikacijski sistemi, ki se razlikujejo med posameznimi pasmami in državami. V raziskavi smo najprej opredelili različne barve dlake pri posavskem konju z metodo barvne spektrofotometrije po sistemu CIE L*a*b*. Fenotipsko razdelitev barv dlake po Sponenbergu (light bay/svetli rjavec, bay/rjavec, mahogany bay/kostanjev, brown/temni rjavec and seal brown/črnkast rjavec) smo potrdili s spektrofotometričnimi podatki. Vrednosti L*a*b so pri posavskem konju pokazale primerljivo visoko fenotipsko variabilnost rjave barve, pri tem so bili temnejši odtenki povezani z ASIP in MC1R kombinacijo genotipa A/a E/E. Barvna spektrofotometrija po sistemu CIE L*a*b predstavlja učinkovito orodje za kvalitativno in kvantitativno opredelitev/določanje barv pri konjih, zlasti pri lisjakih, pri katerih še vedno ni znana genska osnova variabilnosti v barvi dlake.Ključne besede: posavski konj; MC1R; ASIP; barva dlake; spektrofotometrija; CIE L*a*b
30
Calderon Flores, Paulina, Jin Seok Yoon, Dae Yeon Kim y Yong Weon Seo. "Effect of chilling acclimation on germination and seedlings response to cold in different seed coat colored wheat (Triticum aestivum L.)". BMC Plant Biology 21, n.º 1 (2 de junio de 2021). http://dx.doi.org/10.1186/s12870-021-03036-z.
Texto completoResumen
Abstract Background Flavonoids can protect plants against extreme temperatures and ROS due to their antioxidant activities. We found that deep-purple seed coat color was controlled by two gene interaction (12:3:1) from the cross between yellow and deep-purple seed coat colored inbreds. F2:3 seeds were grouped in 3 by seed coat color and germinated under chilling (4 °C) and non-acclimated conditions (18 °C) for a week, followed by normal conditions (18 °C) for three weeks and a subsequent chilling stress (4 °C) induction. We analyzed mean daily germination in each group. Additionally, to study the acclimation in relationship to the different seed coat colors on the germination ability and seedling performances under the cold temperatures, we measured the chlorophyll content, ROS scavenging activity, and expression levels of genes involved in ROS scavenging, flavonoid biosynthetic pathway, and cold response in seedlings. Results The results of seed color segregation between yellow and deep purple suggested a two-gene model. In the germination study, normal environmental conditions induced the germination of yellow-seed, while under chilling conditions, the germination ratio of deep purple-seed was higher than that of yellow-colored seeds. We also found that the darker seed coat colors were highly responsive to cold acclimation based on the ROS scavenging enzymes activity and gene expression of ROS scavenging enzymes, flavonoid biosynthetic pathway and cold responsive genes. Conclusions We suggest that deep purple colored seed might be in a state of innate pre-acquired stress response state under normal conditions to counteract stresses in a more effective way. Whereas, after the acclimation, another stress should enhance the cold genes expression response, which might result in a more efficient chilling stress response in deep purple seed seedlings. Low temperature has a large impact on the yield of crops. Thus, understanding the benefit of seed coat color response to chilling stress and the identification of limiting factors are useful for developing breeding strategies in order to improve the yield of wheat under chilling stress.
31
Suzuki, Hitoshi, Gohta Kinoshita, Takeru Tsunoi, Mitsuki Noju y Kimi Araki. "Mouse hair significantly lightened through replacement of the cysteine residue in the N-terminal domain of Mc1r using the CRISPR/Cas9 system". Journal of Heredity, 30 de noviembre de 2020. http://dx.doi.org/10.1093/jhered/esaa054.
Texto completoResumen
Abstract A loss-of-function mutation in the melanocortin 1 receptor gene (MC1R), which switches off the eumelanin production, causes yellowish coat color variants in mammals. In a wild population of sables (Martes zibellina) in Hokkaido, Japan, the mutation responsible for a bright yellow coat color variant was inferred to be a cysteine replacement at codon 35 of the N-terminal extracellular domain of the Mc1r receptor. In the present study, we validated these findings by applying genome editing on Mc1r in mouse strains C3H/HeJ and C57BL/6N, altering the codon for cysteine (Cys33Phe). The resulting single amino acid substitution (Cys33Phe) and unintentionally generated frameshift mutations yielded a color variant exhibiting substantially brighter body color, indicating that the Cys35 replacement produced sufficient MC1R loss of function to confirm that this mutation is responsible for producing the Hokkaido sable yellow color variant. Notably, the yellowish mutant mouse phenotype exhibited brown coloration in subapical hair on the dorsal side in both the C3H/HeJ and C57BL/6N strains, despite the inability of the latter to produce the agouti signaling protein (Asip). This darker hair and body coloration was not apparent in the Hokkaido sable variant, implying the presence of an additional genetic system shaping yellowish hair variability.
32
Jivanji, Swati, Gemma Worth, Thomas J. Lopdell, Anna Yeates, Christine Couldrey, Edwardo Reynolds, Kathryn Tiplady et al. "Genome-wide association analysis reveals QTL and candidate mutations involved in white spotting in cattle". Genetics Selection Evolution 51, n.º 1 (8 de noviembre de 2019). http://dx.doi.org/10.1186/s12711-019-0506-2.
Texto completoResumen
Abstract Background White spotting of the coat is a characteristic trait of various domestic species including cattle and other mammals. It is a hallmark of Holstein–Friesian cattle, and several previous studies have detected genetic loci with major effects for white spotting in animals with Holstein–Friesian ancestry. Here, our aim was to better understand the underlying genetic and molecular mechanisms of white spotting, by conducting the largest mapping study for this trait in cattle, to date. Results Using imputed whole-genome sequence data, we conducted a genome-wide association analysis in 2973 mixed-breed cows and bulls. Highly significant quantitative trait loci (QTL) were found on chromosomes 6 and 22, highlighting the well-established coat color genes KIT and MITF as likely responsible for these effects. These results are in broad agreement with previous studies, although we also report a third significant QTL on chromosome 2 that appears to be novel. This signal maps immediately adjacent to the PAX3 gene, which encodes a known transcription factor that controls MITF expression and is the causal locus for white spotting in horses. More detailed examination of these loci revealed a candidate causal mutation in PAX3 (p.Thr424Met), and another candidate mutation (rs209784468) within a conserved element in intron 2 of MITF transcripts expressed in the skin. These analyses also revealed a mechanistic ambiguity at the chromosome 6 locus, where highly dispersed association signals suggested multiple or multiallelic QTL involving KIT and/or other genes in this region. Conclusions Our findings extend those of previous studies that reported KIT as a likely causal gene for white spotting, and report novel associations between candidate causal mutations in both the MITF and PAX3 genes. The sizes of the effects of these QTL are substantial, and could be used to select animals with darker, or conversely whiter, coats depending on the desired characteristics.