| Gene regulation can be a complex process in which many cis- and trans-interactions determine the final pattern of expression: Among these interactions are trans-interactions mediated by the pairing of homologous chromosomes. Here I discuss transvection, the modulation of gene expression mediated by trans-interactions that are dependent on the pairing of homologous chromosomes, in three separate chapters. Chapter I reviews previous published studies of transvection, including molecular mechanisms to which transvection can occur. Chapter 2 discusses my study of transvection at the Malic enzyme locus. Chapter 3 describes future studies for transvection at the Malic enzyme locus. My study describes a novel case of transvection at the Malic enzyme (Men) locus. Using both empirical biochemical and predictive bioinformatic approaches, I show that the removal of putative regulatory elements on a non-functional allele is capable of interacting in trans, and can alter Men gene expression on a functional allele in heterozygotes. Furthermore, I show that non-local factors -- different genetic backgrounds -- are capable of significant interactions with individual Men alleles, suggesting that the trans effect that was documented is modified by both locally and distantly acting elements. In sum, my results emphasize the complexity of gene regulation and the need to understand both small- and large-scale interactions as more complete models of gene regulation and the role of trans-interactions are developed. |
