@article {Bloom019513, author = {Joshua S. Bloom and Iulia Kotenko and Meru J. Sadhu and Sebastian Treusch and Frank W. Albert and Leonid Kruglyak}, title = {Genetic interactions contribute less than additive effects to quantitative trait variation in yeast}, elocation-id = {019513}, year = {2015}, doi = {10.1101/019513}, publisher = {Cold Spring Harbor Laboratory}, abstract = {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.}, URL = {https://www.biorxiv.org/content/early/2015/10/08/019513}, eprint = {https://www.biorxiv.org/content/early/2015/10/08/019513.full.pdf}, journal = {bioRxiv} }