title: Small- and large-effect quantitative trait locus interactions underlie variation in yeast sporulation efficiency.
abstract: Quantitative trait loci (QTL) with small effects on phenotypic variation can be difficult to detect and analyze. Because of this a large fraction of the genetic architecture of many complex traits is not well understood. Here we use sporulation efficiency in Saccharomyces cerevisiae as a model complex trait to identify and study small-effect QTL. In crosses where the large-effect quantitative trait nucleotides (QTN) have been genetically fixed we identify small-effect QTL that explain approximately half of the remaining variation not explained by the major effects. We find that small-effect QTL are often physically linked to large-effect QTL and that there are extensive genetic interactions between small- and large-effect QTL. A more complete understanding of quantitative traits will require a better understanding of the numbers, effect sizes, and genetic interactions of small-effect QTL.
authors.affiliation: Department of Genetics and Center for Genome Sciences and Systems Biology, Washington University School of Medicine, St. Louis, Missouri 63108, USA.
authors.forename: Kim
authors.initials: K
authors.lastname: Lorenz
authors.forename: Barak A
authors.initials: BA
authors.lastname: Cohen
mesh_terms: D000483:Alleles; D004843:Epistasis, Genetic; D057898:Hemizygote; D008126:Lod Score; D011110:Polymorphism, Genetic; D040641:Quantitative Trait Loci; D012441:Saccharomyces cerevisiae / Q000235:genetics* / Q000254:growth & development*