Faculty Research Associate
MAJOR AREA: Evolutionary Developmental Biology, Genetics
OFFICE: B09E Life Science
Our long term goal is to use an integrated approach, combining developmental genetics, cell biology, genomics and mathematical modeling to understand how reproductive strategies evolve to changes in the environment. This research touches on several areas that span from basic research (e.g., evolutionary mechanisms) to biomedical research (e.g., how a cell divides asymmetrically). Nematodes offer many advantages for this integrative approach because they are very diverse in terms of mating systems, can be easily cultured in the laboratory, and the knowledge and tools developed for Caenorhabditis elegans can often be applied to other species. Most terrestrial nematodes consist of males and females that reproduce by outcrossing. Interestingly, the females of a few lineages of nematodes (including C. elegans) independently evolved the ability to transiently produce sperm that is used for self-fertilization. Thus, these species with hermaphrodites and males can facultatively reproduce by outcrossing or by selfing. To address how male/female species evolved into hermaphroditic species, we are studying nematode species that might be an evolutionary transitory state between mating systems.
We are also studying what is the possible role of transposons in Hox gene regulation and evolution of lizards. Anole lizards show a large accumulation of transposable elements in the Hox cluster, a genomic region with a high concentration of developmental genes. It has been assumed that the Hox cluster is very sensitive to genomic perturbations because addition or deletion of Hox intergenic material in the mouse results in major changes in Hox gene expression and phenotypic abnormalities. It has been considered that the presence of extremely few or no transposons in Hox clusters of most vertebrates is evidence for strong selection against changes in this genomic region. We hypothesize that mutations in the Hox cluster caused by transposable elements provided the raw material for phenotypic evolution of anoles. To address this hypothesis, we have been analyzing variation in transposon accumulation in the Hox cluster, as well as expression of Hox genes and skeletal morphology in Anolis carolinensis.