DISSERTATION RESEARCH: The Role of Recombination in Transposable Element Proliferation in Daphnia Pulex

Indiana University, Bloomington IN

Investigators

Abstract

Transposable elements (TEs) are regions of DNA that have the capacity to move around the genome in which they are found. Despite their longtime characterization as "junk", TEs have become recognized as important and ubiquitous components of eukaryotic genomes. As a result, there is great interest in what factors influence the dynamics of TE movement. Recombination among host genomes during sexual reproduction may have an especially interesting role in TE proliferation because it simultaneously provides a mechanism by which TEs may easily be gained (e.g. due to insertions when DNA molecules break and exchange material), and an opportunity for TEs to be lost via independent assortment of chromosomes lacking new insertions. Using Daphnia pulex as a model, we can examine the role of recombination in TE proliferation during both sexual and asexual reproduction. Understanding TE movement is important because TEs introduce a significant source of genetic variation upon which natural selection can act. In some cases, TEs insert into genes and disrupt normal function leading to disease. Alternatively, TEs can insert into or near genes, providing novel or regulatory function. Understanding how recombination influences TE dynamics is a key part of understanding their overall role in the genome.