The molecular mechanisms that underlie the origin of evolutionary novelties are unknown. Studies on what appear to be novel characteristics have found that they are often the loss of previously existing characters in the population, not the gain of a new phenotype. However, these and other studies have pointed to regulatory changes being the prevailing underlying driver of phenotypic change and novel morphology origination.
Hypotheses on how regulatory change occurs have suggested that the highly repetitive genome elements, transposable elements (TEs), could play a role. The sequence content within a TE could be exapted to play the role of a regulating element in the genome. However, it is still unknown if TEs integrate into the genome with regulatory capabilities that becomes unlocked upon exposure to the proper transcription factors (TFs) or if further mutations are needed to gain that function. Furthermore, the consequences of the expression of the genes regulated by these TE enhancers in the development of novel phenotypes are unexplored.
I am currently evaluating TEs to determine their predisposition to regulatory function and exploring the role regulatory changes had in the evolutionary origin of novel gene regulatory systems in mammalian pregnancy. Combining evolutionary and molecular genetic techniques allows me to functionally characterize the ancestors of the extant regulatory elements in our human endometrial stromal cell (hESC) in vitro model of pregnancy. This characterization allows me to examine how TE-mediated changes to gene regulatory systems may have allowed for new expression in hESCs of genes to be recruited into the production of a novel trait.