Genetic architecture is the underlying genetic basis of a phenotypic trait and its variational properties. Phenotypic variation for quantitative traits is, at the most basic level, the result of the segregation of alleles at quantitative trait loci (QTL). Environmental factors and other external influences can also play a role in phenotypic variation. Genetic architecture is a broad term that can be described for any given individual based on information regarding gene and allele number, the distribution of allelic and mutational effects, and patterns of pleiotropy, dominance, and epistasis.
There are several different experimental views of genetic architecture. Some researchers recognize that the interplay of various genetic mechanisms is incredibly complex, but believe that these mechanisms can be averaged and treated, more or less, like statistical noise. Other researchers claim that each and every gene interaction is significant and that it is necessary to measure and model these individual systemic influences on evolutionary genetics.
Genetic architecture can be studied and applied at many different levels. At the most basic, individual level, genetic architecture describes the genetic basis for differences between individuals, species, and populations. This can include, among other details, how many genes are involved in a specific phenotype and how gene interactions, such as epistasis, influence that phenotype. Line-cross analyses and QTL analyses can be used to study these differences. This is perhaps the most common way that genetic architecture is studied, and though it is useful for supplying pieces of information, it does not generally provide a complete picture of the genetic architecture as a whole.
Genetic architecture can also be used to discuss the evolution of populations. Classical quantitative genetics models, such as that developed by R.A. Fisher, are based on analyses of phenotype in terms of the contributions from different genes and their interactions.
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En génétique, l'épistasie désigne l'interaction existant entre deux ou plusieurs gènes. Cela s'oppose à l'idée simpliste qui voudrait qu'un individu ne soit que la somme de l'ensemble de ses gènes. Il y a par exemple épistasie lorsqu'un ou plusieurs gènes (dominants ou récessifs) masquent ou empêchent l'expression de facteurs situés à d'autres lieux génétiques (locus). L'existence de gènes dominants ou récessifs a été mise en évidence par Mendel dès le milieu du 19e siècle, mais le terme d'épistasie n'est introduit formellement qu'en 1907 par Bateson.
Sir Ronald Aylmer Fisher est un biologiste et statisticien britannique, né à East Finchley le et mort le . Richard Dawkins le considère comme et Anders Hald comme l'homme qui a – . Pour Bradley Efron, il est le statisticien le plus important du . Dans le domaine de la statistique, il introduit de nombreux concepts-clés tels que le maximum de vraisemblance, l'information de Fisher et l'analyse de la variance, les plans d'expériences ou encore la notion de statistique exhaustive.
Couvre les bases de la génétique, de l'hérédité des allèles, de la relation génotype-phénotype et de la génétique des populations.
Explore la génétique, les lois de Mendel, les relations allèles, et les modèles d'héritage dans les plantes de pois et les traits humains.
Couvre le patrimoine génétique au-delà de Mendel, en explorant des concepts tels que la dominance incomplète, la codominance, les allèles multiples et l'épistasie.
Mutations to gene regulatory networks can be maladaptive or a source of evolutionary novelty. Epistasis con-founds our understanding of how mutations affect the expression patterns of gene regulatory networks, a chal-lenge exacerbated by the dependence of ...
The focus of the work presented in this thesis is the exploration of the genetic architecture of complex human traits - at the dawn of genomic medicine.The underlying mechanisms explaining the enormously polygenic nature of most human complex traits are ...
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In a context of rapid global change, one of the key components for the survival of species is their genetic evolutionary potential for adaptation. Many methods have been developed to identify genetic variants underpinning adaptation to climate, but few too ...