In eukaryotes such as animals and plants, physical exchange (recombination) between chromosomes during production of gametes can produce novel sets of genetic information, thus yielding new and potentially useful traits. The goal of this project is to understand how certain environmental conditions affect the rate of recombination and, ultimately, the acquisition of new traits. These studies may lead to novel strategies for breeding in agricultural settings, since the goal of such strategies is to produce plants and animals with new and beneficial traits. The project will provide hands-on research training of future scientists, including a graduate student and number of high school students during the summers. In addition, this project will serve as a launching point for presentations to local K-12 schools to promote understanding of genetics and evolution and to spark enthusiasm for scientific inquiry.
Phenotypic plasticity, the capacity of a single genotype to produce different phenotypes in different environments, is pervasive in nature. In spite of its ubiquity the genetic and molecular bases of phenotypic plasticity remain unknown. In particular, the extent to which genes underlying individual traits are the same genes underlying phenotypic plasticity in those traits remains controversial, in part because there are precious few examples for which the underlying genetic architecture of both the trait and any associated plasticity in that trait have been clearly worked out. Recombination rate is an important example of a plastic phenotype. Using meiotic recombination rate as a prototypical plastic trait, this project will test the hypothesis that phenotypic plasticity for a trait is mediated by the same genes underlying population-level variation in that trait. Using Drosophila melanogaster as the genetic model, experiments will include sequencing whole genomes, characterizing which genes are expressed and in what amounts, and association mapping to discover relationships of genotypes to phenotypes. The experiments will provide two sets of data, one identifying genetic loci associated with within-organism variation in recombination rate and the other identifying genetic loci associated with between-population variation in recombination rate. If the same loci are identified in the two data sets, this result would provide important new insights into the genetic basis of phenotypic plasticity.
