Standing variation in complex traits is the results of the concerted action of several genes and the environment. Examples of complex traits are heart disease and height in humans, and egg production in poultry. We know very little about the genetic basis of variation in such traits. A question central to the origin and maintenance of such variation, as well as our ability to manipulate causative genes, is: are the alleles which contribute to variation in these traits generally rare or more intermediate in frequency? The experiments of this proposal will use a novel genetic mapping scheme in Drosophila to distinguish between these competing hypotheses.
The answer to the question, what is the genetic basis of variation in complex traits, has many potential repercussions. Whether contributing alleles are generally at low or high frequency suggests strategies that will most profitably be employed in order to clone causative genes. Optimal cloning strategies will impact human health and welfare via designer drugs and/or diagnostics for complex disease. The frequency of alleles contributing to complex traits will allow us to ultimately understand the role of the phenotypic variation we commonly observe for complex traits in allowing species to adapt to environmental change.
