Association studies are designed to identify main effects of alleles across a potentially wide range of genetic backgrounds. To control for spurious associations, effects of the genetic background itself are often incorporated into the linear model, either in the form of subpopulation effects in the case of structure or in the form of genetic relationship matrices in the case of complex pedigre...

There is a difference in viewpoint of developmental and evo-devo geneticists versus breeders and students of quantitative evolution. The former are interested in understanding the developmental process; the emphasis is on identifying genes and studying their action and interaction. Typically, the genes have individually large effects and usually show substantial dominance and epistasis. The lat...

Fruit shape index (round shape) and seed size have important effects on pumpkin yield. To investigate these traits to create the most desirable state, a cross was made between two cultivars. This study aimed estimate main gene (additive, dominant di-genic epistasis) determine mode of inheritance for fruit by generation mean analysis. Six generations, namely P1, P2, F1, F2, BC1, BC2 from Zucchin...

We present a new parameterization of physiological epistasis that allows the measurement of epistasis separate from its effects on the interaction (epistatic) genetic variance component. Epistasis is the deviation of two-locus genotypic values from the sum of the contributing single-locus genotypic values. This parameterization leads to statistical tests for epistasis given estimates of two-loc...

Most phenotypes are determined by molecular systems composed of specifically interacting molecules. However, unlike for individual components, little is known about the distributions of mutational effects of molecular systems as a whole. We ask how the distribution of mutational effects of a transcriptional regulatory system differs from the distributions of its components, by first independent...

Graphical Abstract Errors are regularly made when SARS-CoV-2 replicates its RNA genome. The viral polymerase complex is error-prone with imperfect proofreading abilities. These errors or mutations often lead to deleterious neutral effects on the virus. However, sometimes these have a positive effect and create genetic variants of virus different features including increased transmissibility, pa...

Wright first introduced the idea that random genetic drift and classical mass-action selection might combine in such a way as to allow populations to find the highest peak in complicated adaptive surfaces. His theory assumes large but structured populations, in which mating is spatially local. If gene flow is sufficiently low, and the subpopulations (demes) are small enough, they will be subjec...

Inbreeding generally results in deleterious shifts in mean fitness. If the fitness response to increasing inbreeding coefficient is non-linear, this suggests a contribution of epistasis to inbreeding depression. In a cross-breeding experiment, Salathe & Ebert (2003. J. Evol. Biol. 16: 976-985) tested and found the presence of this non-linearity in Daphnia magna. They argue that epistatic intera...

Epistasis, a term coined by William Bateson in 1909 [1], refers to the interdependence of mutations in their phenotypic effects. Let the phenotypic value of a trait relative to that of the wild type be fA and fB for mutants A and B, respectively, and let the phenotypic value of the corresponding double mutant be fAB. Although variation exists, epistasis is usually defined by ε = fAB − fAfB and ...