Selection and complex multige traits

HASSON, E.R.; FANARA, J.J.; FRANKEL, N.

eLS citable reviews in the life sciences

John Wiley & Sons

Año: 2013 p. 1 - 9

1523-8253

Phenotypic characters that display continuous variation are usually called “quantitative traits” or “complex traits”. Alternatively, geneticists refer to them as “multigene traits”, because the underlying genetic architecture is assumed to be polygenic. Analyses of the genetic architecture of diverse quantitative traits suggests that the number of loci (quantitative trait loci, QTLs) affecting trait variation can be very different. Moreover, experimental studies report contrasting  genetic  architectures, where  either  large-effect QTLs or  small-effect QTLs  explain most of  the phenotypic  variance.  In addition, recent reports highlight the pervasiveness of epistasis. Considerable evidence, obtained with the QST-FST methodology, supports the idea that natural selection plays a key role in the evolution of complex traits. Nevertheless, the identification of a representative number of genes underlying QTLs is necessary to determine the contribution of selection, drift and gene flow for the evolution of complex traits.