Postdoctoral Research Scientist
Princeton, NJ United States
Areas of Expertise:
Population and evolutionary genomics
Drosophila, Anopheles, Aedes
The goal of my present research is to dissect the causative genes and mutations underlying complex traits, and trace the stepwise process by which the identified causative alleles arose and spread through an isolated population to generate a fixed morphological phenotype. The species Drosophila santomea exhibits a recently evolved, drastic shift in its pigment patterns that represents an optimal model system in which to dissect complex polygenic traits. Previous work identified the gene underlying one of four major QTL contributing to this trait. Analysis of multiple individuals in the population revealed that causative alleles of this gene arose several times in parallel in the D. santomea population (i.e. a “soft sweep”).
During my postdoctoral research I will employ molecular genetic techniques (fine-scale QTL mapping, CRISPR/Cas9 gene editing, reciprocal hemizygosity tests) to identify causative genes and mutations responsible for an additional QTL with a large effect on the D. santomea pigmentation phenotype. Using a combination of molecular and genomic techniques (transgenic complementation, RNA-seq), I will then assess how pigmentation loci interact with each other, as well as how they impact the genome-wide profile of expression. Finally, I will survey population variation at the causative loci to assess whether a similar soft sweep occurred, and determine whether these genes exhibit recent or ancient signatures of positive selection. This study will provide a rare view of the evolution of a complex morphological trait that integrates molecular studies of gene function with evolutionary processes occurring at the population level.