Academic literature on the topic 'Seed phenotypic characteristics'

Recurrent phenotypes are similar or identical phenotypic traits with discontinuous phylogenetic distributions, which owe their similarity to common ancestry (homology). A recurrent trait may be found as a fixed trait, as an alternative phenotype (one morph of a polymorphism or polyphenism), or as a low-frequency developmental anomaly. Recurrence, then, is the phyletically disjunct appearance of homologous traits. An example is the repeated evolution of larviform (paedomorphic) adults in salamanders. The larviform morph is characterized by retention in the reproductive stage of homologous larval traits such as external gills and a tail. This has involved changes at various points in the hormonal mechanism that controls metamorphosis in all salamanders (chapter 25), perhaps under selection for accelerated reproduction in stressful environments (Whiteman, 1994). As is characteristic of recurrent phenotypes, the occurrence of the reproductive larviform adult morph varies in frequency from one species of salamander to another: it can be absent, an anomaly (<5% of population), a common (>5%) alternative to complete metamorphosis, or a predominant or fixed form. Even within the genus Ambystoma, the unmetamorphosed larviform adult occurs as an occasional anomaly in some populations, as a facultatively expressed alternative phenotype in others (e.g., A. tigrinum) and as a fixed form in others (e.g., A. dumerilii; Collins et al., 1993). All atavisms and reversions (see chapter 12) are examples of recurrence. Discontinuity of expression is expected in combinatorial evolution, where traits are turned off and on and expressed in different combinations due to regulatory change. The growing evidence of homoplasy in phylogenetic studies is important evidence that combinatorial evolution occurs and that homoplasy itself is worthy of study, not just a source of “noise” in cladistics (Wake, 1996a). Homoplasy has been defined as “possession by two or more taxa of a character derived not from the nearest common ancestor but through convergence, parallelism, or reversal”. More simply, homoplasy is the recurrence of similarity in evolution (Sanderson and Hufford, 1996).

Abstract A review of reliable examples of transdifferentiation indicates the presence of several general features common to most of them. This is surprising, because examples discussed in this monograph cover such a variety of systems in a number of different organisms and cell types (Table 9.1). Basically, transdifferentiation is a unidirectional process, from cell type A to B. Reversible change from B to A is rare, or more precisely, is outside the present definition of transdifferentiation. Such examples can be called modulation which sometimes denotes a fluctuation of minor phenotypic changes. Within examples of trans-differentiation discussed earlier, interconvertible change is found, for example, between subclasses of amphibian chromatophores. However, even in this system, there is a basic tendency to change towards melanophores, which are the most stable subclass to become an end result of a series of transdifferentiation steps (see Chapter 4.2). Lens is the terminus of more distinct changes among three major elements of vertebrate eyes. Therefore, the tripartite relationship assumed in the eye transdifferentiation system (Okada et al. 1975; Pritchard 1986) may also hold true among the three subclasses of amphibian chromatophores (Fig. 9.1).

Schizophrenia and bipolar disorder have been considered to be separate conditions since their initial definition by Kraepelin in the late 1890s. Despite the distinctions between the conditions in terms of their definitional criteria (delusions and hallucinations versus wide-ranging changes in mood), there are multiple shared phenotypic features. These features include cognitive impairments, everyday disability, and suicidal ideation and behavior. Genomic approaches initially focused on family and population characteristics, findings overlapping risk within families. Recent efforts have shifted to large-scale genome-wide association studies, targeting both susceptibility to the conditions and genomic correlates of the shared phenotypic features. Among the major shared phenotypic features, it appears that polygenic risk for schizophrenia and bipolar disorder also overlaps with the genomics of cognitive functioning, including cognitive functioning in the general population. Polygenic risk for depression is also associated with both schizophrenia and bipolar disorder. While most of the genomic influence to date in these two conditions has arisen from common variants, rare variants such as alterations in copy number variations have been seen to be more strongly associated with schizophrenia than bipolar disorders, but sample size differences may be responsible for the lack of effects in bipolar disorder. As sample sizes increase, it is anticipated that even more overlap between bipolar disorder and schizophrenia will be detected, as well as the continued exploration of aggregated phenotypic and genomic features in the two conditions.

Recent advances are nowadays providing opportunities to examine the complexities of organs and organisms at the single-cell level. The conventional cell.based analysis mainly examines the cellular processes from the bulk of cells but single.cell omics provides a more detailed insight into individual cell phenotypes, thus giving a link between the phenotype and genotype of cells. Single-cell analysis can be performed at genome, epigenome, transcriptome, proteome and metabolome levels and thus makes it possible to come across mechanisms not seen during the sequencing of bulk tissues. Researchers need to isolate single cells before the initiation of single-cell analysis. For this, various strategies like FACS, MACS, LCM, micro-manipulation and micro-fluids are used for cell isolation depending upon their physical properties and cellular biological characteristics. The analysis of single-cell data at multiple levels gives us an unusual view of multilevel transformation at the single-cell level and thus providing a better chance to discover novel biological processes. High throughput analysis of single cells at genome, transcriptome and proteome levels provides unique and important insights into cell variability and diverse processes like development, genetic expressions and severity of different symptoms in disease pathogenesis.

Abstract In litter-bearing rodent species, the location that a male or female fetus occupies relative to siblings of same or opposite sex influences its level of prenatal exposure to gonadal hormones. In particular, varying amounts of prenatal exposure to testosterone produce cascades of neurendocrine events that, in turn, result in variation in such biologically important characteristics as the timing of puberty, an individual’s lifetime fecundity, the sex ratio of its offspring, and the magnitude of its parental investment. Consequently, studies of intrauterine effects on adult patterns of reproduction provide a means of examining the relationship between normally occurring variation in perinatal exposure to hormones and the variation in reproductive tactics often seen in mammalian populations. Dams can only indirectly influence the intrauterine position of their offspring by varying the size and sex ratio of their litters and the distribution of litter members within the uterus. However, because the same hormonal mechanisms that support indirect maternal effects on behavior also support direct maternal influences on the phenotype of offspring, examination of effects of intrauterine position increases understanding of direct maternal effects on phenotypes of adult mammals.

● To optimize antimicrobial therapy for the management of individual patient’s infection. ● For surveillance purposes, which in turn inform local/national/international clinical guidelines. ● For the management of infection control and prevention. Broadly speaking, resistance is detected by observing its phenotypic expression (activity of the candidate drug(s) against the target bacterium) or detecting the underlying genotypic determinant (resistance genes). Commonly used methods in clinical diagnostic laboratories generally fall under the ‘phenotypic’ category. These share similar traits— ease of use, reproducibility, scalability, quick turnaround of results and relative low cost of materials/reagents required. Moreover, decades of experience and fine-tuning have seen them established as methods of choice in most microbiology laboratories. Most phenotypic test methods are reliant on the use of clinical breakpoints set by national and international bodies (e.g. EUCAST and CLSI) to determine susceptibility/resistance. These guidelines are regularly subject to updates with input from leading experts and latest research findings. It is important for clinical diagnostic laboratories to adhere to best practice guidance set out by these bodies and keep up-to-date with the latest guidelines. Growth characteristics (on artificial media) of the bacterium of interest are extremely important in conventional phenotypic methods. As this presents a big obstacle for slow growers and ‘unculturable’ pathogens (e.g. Mycobacterium tuberculosis, Mycoplasma spp.) it has led to the introduction of genotypic methods of resistance detection in the clinical diagnostic laboratory. meteoric rise in the world of microbiology. Compared with conventional phenotypic methods, molecular genotypic-based tests are better suited for automation and reduce dependence on skilled workers for result interpretation. They therefore deliver the rapid turnaround demanded by modern medicine. Antimicrobial susceptibility tests (ASTs) is a term used to describe a range of phenotypic methods that employ direct observation of the action of antimicrobials against a target microorganism. This is the most commonly used method in clinical diagnostic laboratories for detecting resistance in bacteria. A. Disc diffusion Growth medium: Standardized agar plates (usually unsupplemented, but addition(s) may be necessary for bacteria with specific growth requirements). Antibacterial component: Fixed dose in standard size circular paper discs or tablets.

Abstract Mononuclear phagocytes represent a host-wide system of cells which provide a broad range of physiologically important services (Adams and Hamilton, 1984, 1992a; Nathan and Cohn. 1995: Van Rooijen et al., 1996; Bosque et al., 1997; Gordon. 1998). Not surprisingly, members of this cell system can exhibit a diverse array of characteristics. The mononuclear phagocyte lineage develops in the bone marrow and, following entry into the circulation, seeds essentially all tissues. Thus, under resting conditions, the differences between macrophages in different organ locations are likely to result from developmental signals encountered within individual tissue sites. Such differences are not the consequence of ‘activation’ as they reflect the specific physiology of each tissue and are stable over time. Examples of such developmentally distinct mononuclear phagocyte populations include microglia. Kupffer cells, splenic macrophages and the spectrum of myeloid dendritic cells.

So far, I have outlined the general properties of phenotypes, shown how they relate to development, and presented a model of adaptive evolution based on established principles of development and genetics. Now, using this general framework, I can summarize how developmental plasticity facilitates evolution. Jacob (1977) characterized evolution as “tinkering.” It shuffles and recombines what is already there. Frazzetta (1975), in another felicitous comparison with machines, wrote that evolution manages “the gradual improvement of a machine while it is running” (p. 20). Both of these qualities are possible due to characteristics of phenotypes that are not shared with most machines. Tinkering works because the phenotype is made of recombinable modular components that can be turned off and on in different conditions and can function in more than one context, what Gerhart and Kirshner (1997; Kirschner and Gerhart, 1998) call “weak linkage” to any particular use. Improvement without disruption of function works because of the remarkable active flexibility, and redundancy, in the development of parts. As a result of these two qualities—modularity and plasticity—an organism has the unmachinelike ability to respond to a new situation or to a new gene with the production of a new trait, and then to multiply, through reproduction, the ability to produce this trait. Differential reproduction starts the cycle of variation, selection, and cross-generational change that we call evolution—the most unmachinelike process of all. Many reasons have been given to believe that evolutionary change is difficult and even resisted in a well-adapted population (see chapter 1). The evolution of a novel specialization requires that a single lineage persist while undergoing extensive change. The conditions sometimes mentioned as favoring directional evolution, such as strong competition, very different or changing environments, small founder populations, or very long periods of time (see Mayr, 1982b), also favor population extinction. The idea of developmental cohesiveness, outlined in chapter 1, led to the further belief that major developmental change early in ontogeny would be disruptive. The cohesiveness theme persists even though it long has been clear that innovation does not occur exclusively by terminal addition (see chapter 1).

Abstract Within any butterfly population no two individuals are identical. This applies both to their genes or genotype and to their phenotype or set of individual characteristics resulting from interactions between the genes and the environment during development. The reproductive success or fitness of an individual depends on how well its phenotype is adapted or fitted to the environment which it experiences. Some species of butterfly exhibit discrete genetic forms which differ in wing pattern and which occur together within populations. Research on such poly¬morphisms has contributed much to our under¬ standing of the processes of adaptation to the environment. Having first introduced some basic concepts, this chapter describes work on poly¬morphisms in butterflies together with recent insights into how wing patterns are developed. Rare aberrations much beloved by butterfly collectors (see Russwurm 1978) are not considered in detail here since they are unlikely to be significant in evolution¬ ary terms even when they have a genetic basis (see Fig. 8.1).

A significant reserve for increasing the efficiency of mutational breeding of lettuce (Lactuca sativa L. var. secalina) is the use of score (code) scales to assess the characteristics of the manifestation of quality traits that cannot be determined in physical units of measurement. The purpose of the experimental work is to establish the effect of a mutagenic factor (γ-irradiation) on the formation of qualitative traits that determine the phenotype of the leaf blade and to study the correlation between their manifestation and the manifestation of selective value quantitative traits in the created mutant generation M4 of leaf lettuce. The research methodology is based on the application of a physical mutagenic factor to expand the genetic diversity of leaf lettuce (pre-sowing γ-irradiation with doses of 7, 11 and 15 kR of air-dry seeds), a point (code) assessment of the peculiarities of the manifestation of quality traits in the M4 mutant generation, non-parametric criteria for the difference of the investigated biological objects, computational and analytical calculations of statistical indicators for quality features, correlation analysis. The results of the conducted research made it possible to differentiate γ-irradiation doses according to the degree of effectiveness in creating mutant lines of leaf lettuce with different degrees of genetic distance from the original form – the Divogray variety. The peculiarities of the mutagenic effect of γ-irradiation on the expansion of the spectrum of genotypic variability of leaf lettuce according to 17 qualitative features that determine the phenotype of the leaf blade have been clarified. Among the lines, four (D(7) (ind. selection – 1), D(11), D-1(15) and D-2(15) were selected, in which the range of variation of the indicator "Average index of normalized values" (Xmed = 0.77...1.47) was within the margin of error of the average statistical value of the corresponding indicator of the Divogray variety (Xmed = 1.07±0.69). The exception is line D(7), which had a statistically significant deviation from the original form (Xmed = 0.42±0.39). The most effective mutagenic factor turned out to be a dose of γ-irradiation of 7 kR, because under the conditions of its use, two mutant samples were formed (D(7) and D(7) (ind. selection – 1), which had the greatest genetic distance from the Divogray variety (rs = -0.45...0.40). Using two doses of γ-irradiation, 11 kR and 15 kR, one mutant sample was obtained, D(11) and D-1(15), respectively, which also had the lowest genetic affinity with the Divogray variety (rs = 0, 38...0.40). It was established that a correlation of medium strength (rs = -0.50...0.48) of the non-parametric statistical indicator "Average index of normalized values" occurred with the levels of manifestation of such quantitative features as "Height of socket", "Width of socket" and " The number of leaves on one plant” (rs = 0.48). Practical implications. Therefore, genetically inherited phenotypic changes in the morphology of the leaf blade are most correlated with quantitative traits that determine the architecture of lettuce plants and are a structural component of the yield of mutant samples. The established, statistically reliable, correlations make it possible to forecast phenotypic changes in the mutant generation M4 and above of leaf lettuce based on the above-mentioned quantitative characteristics, which is a factor in the optimization of the breeding process. Value/originality. The introduction into the selection process of methods for analyzing genetic changes of qualitative traits based on point evaluation allows for a more in-depth study of the patterns of inheritance of quantitative selection-important traits within a certain genotype of a vegetable plant species, to create more objective prognostic models of the formation of approbation traits of future varieties and F1 hybrids, to create working collections of original lines with the expected predicted result of phenotypic manifestation in the offspring.

Background and objectives. Video game addiction (VGA) is characterized by a pattern of impaired control gaming behavior, prioritizing gaming over other daily activities and responsibilities. The rapid increases of the VGA rates worldwide advice the urge of new studies focused on examining the existence of differences in the phenotype of patients treatment-seeking due the problematic video game use. Method. Sample comprised n=107 participants recruited at the Pathological Gambling Outpatients Unit of the Bellvitge University Hospital (Barcelona). Mean age was 24.1 yrs-old (SD=10). Most participants were men (91.6%), single (88.8%) and into mean-low to low social position indexes (84.1%). Two-step clustering analysis explored empirical latent groups based on a broad set of indicators, including sociodemographic, psychopathological state and personality traits. Results. Two exclusive groups emerged. Cluster 1 (labeled as moderate maladaptative functioning, n=72, 66.1%), was composed mainly by single, unemployed men, with the younger age of onset, the earlier onset of the video game problematic use, the shorter progression of the problems, better psychopathological state and more functional personality traits. Cluster 2 (labeled as severe maladaptative functioning, n=35, 32.7%), included a higher proportion of not-single and employed women, with an older age, a later onset and a longer duration of the video game related problems, worse psychopathological state and more dysfunctional personality profile. Conclusion. VGA is a heterogeneous group with regard to gambling phenotypes. The identification of the diverse latent classes provide empirical evidence contributing to the conceptualization of this behavioral addition, as well as for developing reliable and valid screening tools and effectiveness intervention plans focused on the precise characteristics of the patients.

To speed up the selection process of hybrids and the selection of parental forms for crosses, it is important to pay attention to both the phenotypic and genetic potential of plants. In order to increase yields by selecting optimal parameters for wheat selection based on short-stemmed and coarse-grained characteristics in a dry climate, we studied the genes of the “green revolution” group Rht and coarse-grained TaGW, TaGS, and carried out a correlation analysis between the genetic potential of wheat varieties and hybrids and their phenotypic manifestation in drought conditions. The results of the studies showed that the Rht-D1b gene significantly reduces the height of plants by 51.67 %, and also reduces the length of the coleoptile by 30.45 %. At the same time, the TaGW8-B1a gene increases the grain width by 13.37 %. However, in the presence of Rht-D1b, Rht-B1b genes in the genome, the average weight of 1000 seeds was 35.06 g (p<0.05), while the Rht-B1b gene increased it by 9 % (p<0.05), both Rht-D1a, Rht-B1a alleles give a mass of 1000 seeds of 37.96 g (p<0.05). The data obtained indicate the relationship of phenotypic and genetic parameters in wheat between the genes of coarse-grained and short-stemmed, which makes it possible to select based on the genetic parameters of varieties and hybrids, thereby speeding up the selection process.

The present study was carried out to estimate the response of native wheat genotypes (Tri-ticum aestivum L.) Moldova 614, Moldova 66 and the Selania/Accent line to water stress in the early stages of growth and to use sources with a high level of adaptability in resistance improve-ment programs to drought. The effect of osmotic stress on early growth stages was evaluated un-der temperature conditions of 15oC and 25oC, using polyethylene glycol (PEG 6000) treatment at concentrations of 10% and 20% d/v. In the conditions of water restrictions produced by PEG 6000 in the 10% concentration both at the optimal temperature of 25oC, but also at the suboptimal one of 15oC, the investigated indices showed the response of tolerance, but also of high resistance. When administering the osmotic in the concentration of 20% at a temperature of 25oC, both the average resistance and the sensitivity of the investigated characters were attested. Moldova 614 recorded the lowest reduction of 23.7% for plant vigor index, while L Selania/Accent recorded a massive reduction of 72.8% for seed vigor index. In the conditions of interaction of major stress factors (PEG 20% x 15oC) the genotypes responded with a severe decrease of the inves-tigated parameters. More advantageous PVI was attested only in the Moldova 614 genotype. The variance analysis revealed the temperature factor with the highest weight in the variability of the root and stem length characters (85.7% and 72.2%). The water deficit explained respec-tively 12.0% and 22.5% of the variance of the characters, while the significant interactions of the stress factors attested advanced weight for the length of the stem in relation to the length of the root. This phenomenon indicates the increased vulnerability of the stem, a phenomenon also highlighted by the phenotypic character of the root/stem ratio. Purpose.Wheat contributes to global consumption with 55% of carbohydrates, but also 20% of food calories, maintaining an important position in the international grain trade [3]. Abiotic stress extremes such as drought, temperature, salinity, and nutrient imbalance represent major challenges to the grain industry. Drought affects plant growth from germination to matu-rity, causing morphological, biological, physiological, and molecular changes. More likely to be affected are the stages of early vegetation and reproduction [3]. Tolerance to water deficit as well as thermal stress is a difficult, polygenic quantitative characteristic [2, 3]. In efficient and repeatable phenotypic expression of drought tolerance, it is necessary to use simple early scre-ening methods [2, 4]. One of the sources of improving wheat drought tolerance is presented by the introgression of resistances from the wild gene pool as well as local ones [3]. Anticipating testing in field conditions, targeted are the tolerance indices in the early growth phase under artificially stressful conditions [2, 4]. The present study aimed to select local wheat genotypes, well adapted to the induction of water stress by the osmotic PEG 6000 under different tempe-rature conditions.

An estimated 2.5 percent of the American population has heart valve (HV) disease and more than 100,000 US patients require a prosthetic valve replacement each year [1]. However, prosthetic valves can cause accelerated calcification leading to recurrence of HV disease in patients [2]. Thus, the development of a suitable tissue-engineered heart valve (TEHV) would greatly benefit patients with HV disease. Aortic valve interstitial cells (AVICs) play a crucial role in the progression of aortic valve disease as well as the maintenance of normal valve. Therefore, in order to design a suitable TEHV, these specialized cells need to be better understood. AVICs are known to synthesize ECM and express matrix degrading enzymes and their inhibitors that mediate and regulate remodeling of ECM components [3]. Interestingly, it was recently established that AVICs sense the stiffness of their surrounding ECM in vivo and are phenotypically responsive to mechanical cues with AVICs differentiating into myofibroblasts or osteoblasts, which are pathologic markers. Specifically, soft collagen gels (∼34kPa) caused less differentiation of AVICs than stiffer collagen gel (∼100kPa) [4]. However, for these experiments the AVICs were cultured on tissue culture polystyrene (TCPS) for at least one passage, and it is likely that AVICs cultured on TCPS might retain modified characteristics of AVICs in tissue prior to seed them on soft gels because of the memory to rigid substrate stiffness. Therefore, in this study, we examined the phenotype and function of AVICs on substrates that mimic ECM stiffness of adult leaflet as well as of developing embryo. In addition, we examine the effects of transforming growth factor-β1 (TGF-β1) which has been the most extensively studied cytokine initiator of fibrotic response of AVICs.