Comparative biology of transposable element proliferation (Visiting Scholar)
Availability of genomic sequences from a wide variety of taxa are revealing intriguing patterns in genomic evolution, including gene content and chromosomal structure. One of the most striking and variable contrasts between genomes arises when comparing the repetitive element compliment of genomes. A large proportion of eukaryotic genomes is comprised of widely variable but repetitive centromeric, telomeric, and transposable elements (TEs). Evidence from several evolutionary lineages suggests TEs contribute to changes in genome structure and function by altering genome size, gene expression and the rate and placement of recombination. These genomic changes, in turn, result in corresponding changes to morphology and life history traits. Despite the prevalence and importance of TEs to organismal and genomic evolution, research that compares patterns of TE proliferation between organisms is still in its infancy. I propose to explore TE presence and distribution in a phylogenetic framework in the Asparagales (onion, asparagus, iris, agave, orchid), a diverse order of plants about which little genomic information is published, but which contains enormous variation in both genome size and life history traits. First, I plan to mine genome sequence surveys from across Asparagales to characterize and quantify TEs within an organism. Second, I will develop a qualitative framework with which to compare proliferation of TEs using a phylogeny. Finally, I plan to explore possible correlations between TE proliferation, diversification rates and life history traits.