PROJECT SUMMARY
The laboratory studies how genetic variation, sex differences, and environmental heterogeneity affect
phenotypic differences within and between species. Determining how genetic and environmental factors affect
phenotypes—and how those effects differ between sexes—is essential for understanding the mechanistic
basis of traits, including many human diseases. The laboratory’s current research has three primary areas of
focus: the genetic basis of sex-specific cellular, physiological, and behavioral variation; sex chromosomes and
sexually dimorphic gene expression; and the regulation of the immune response to bacterial infection. The
goals for the next five years involve determining the genetic mechanisms responsible for phenotypic variation
within and amongst genotypes, sexes, and environments. This research will address important gaps in our
understanding of why there is phenotypic variance within genotypes, and how that variation relates to
phenotypic differences across genotypes, sexes, and environments. The project will accomplish its goals by
combining experimental and genomic approaches across multiple species that are informative of general
principles because of their unique biological features or available genetic tools. Two of those species—house
fly (Musca domestica) and Drosophila pseudoobscura—harbor natural genetic variation that will be used to
determine how genotype, environment, and sex interact to affect phenotypes. A third species, Drosophila
melanogaster, is a powerful model organism with a rich suite of genetic and genomic resources that will be
used to determine the mechanistic basis of phenotypic variation. The project will use quantitative and
population genomic approaches in all three species to measure how genotype, environment, and sex
contribute phenotypic variation within and among individual organisms. Comparative and functional genomics
approaches across these species and their close relatives will also be used to identify genes and regulatory
networks that could underly phenotypic variation. Hypothesized mechanisms identified from the quantitative,
population, comparative, and functional genomics analyses will be tested using the powerful D. melanogaster
genetic toolkit. The laboratory is well-suited to perform this work because of its expertise using evolutionary
and functional genomics approaches to study phenotypic and genetic variation within and across species.