'Dissertation Research: Evolution of cis Regulation in Drosophila Maternal Effect Genes'

Pennsylvania State Univ University Park, University Park PA

Investigators

Abstract

0073588 Clark & Dermitzakis Gene regulation during early stages of development entails a complex set of interactions. In the fruit fly (Drosophila), these steps are determined by the maternal contributions of both proteins and messenger RNA (mRNA) to the oocyte as well as by transcriptional and translational regulation of zygotic and maternal genes. The orchestration of anterior-posterior (A-P) patterning in the Drosophila embryo is one of the best-studied systems. The complexity of this system and the dual nature of control (maternal and zygotic) provide an attractive model for microevolutionary studies of gene regulation and maternal effect dynamics. This study uses experimental and theoretical approaches to model and interpret the pattern of genetic variation in regulatory sequences and the evolutionary potential within and between species for genes involved in this process (bicoid, nanos, caudal, hunchback, pumilio). Embryonic phenotypes will be scored, including the distribution and quantities of morphogen mRNA and proteins in third-chromosome-homozygous lines of Drosophila melanogaster and related species. The upstream regulatory DNA sequences (promoters) of these genes will be sequenced and correlated with phenotypic variation. The goals are to identify natural existing variation in the genes involved in the dosage-dependent process of A-P patterning, to test the hypothesis of compensatory mutations, and to parameterize models of evolutionary change in regulatory regions.