%0 Journal Article
%A Bloom, Joshua S.
%A Kotenko, Iulia
%A Sadhu, Meru J.
%A Treusch, Sebastian
%A Albert, Frank W.
%A Kruglyak, Leonid
%T Genetic interactions contribute less than additive effects to quantitative trait variation in yeast
%D 2015
%R 10.1101/019513
%J bioRxiv
%P 019513
%X Genetic mapping studies of quantitative traits typically focus on detecting loci that contribute additively to trait variation. Genetic interactions are often proposed as a contributing factor to trait variation, but the relative contribution of interactions to trait variation is a subject of debate. Here, we use a very large cross between two yeast strains to accurately estimate the fraction of phenotypic variance due to pairwise QTL-QTL interactions for 20 quantitative traits. We find that this fraction is 9% on average, substantially less than the contribution of additive QTL (43%). Statistically significant QTL-QTL pairs typically have small individual effect sizes, but collectively explain 40% of the pairwise interaction variance. We show that pairwise interaction variance is largely explained by pairs of loci at least one of which has a significant additive effect. These results refine our understanding of the genetic architecture of quantitative traits and help guide future mapping studies.
%U https://www.biorxiv.org/content/biorxiv/early/2015/10/08/019513.full.pdf