9615260 Goodnight A standard assumption of genetical models is that the effect of a gene on the phenotype is constant. Models show, however, that in the presence of gene interaction these effects will not be constant, rather, the effects of genes may change when the frequencies of genes at other loci change. Thus, a gene that is deleterious in one population may be favorable in another population with a different suite of genes at other loci. For example, a gene causing a "genetic disease" in one population or family may be neutral or even beneficial in other populations or families. These models also suggest that a period of small population size may shift the selective values of genes, sending the population down a new evolutionary trajectory. In extreme cases speciation can result. This may have implications for endangered species that have been reduced to very small population sizes. This research will explore the role of gene interaction in population differentiation and species differences. One portion of this research will involve models and statistical analysis designed to detect and interpret gene interaction in molecular quantitative trait loci (QTL) studies. Of interest will be how to detect interacting QTL, and how to relate these QTL to classical quantitative genetic measures. This will provide important tools for researchers seeking to identify the genetic basis of traits affected by gene interaction. A second portion of this research will examine the role of gene interaction in species differences. This will provide fundamental insights into the role of gene interaction in species formation.
