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Date of Award

Spring 2011

Author's School

College of Arts & Sciences

Author's Department/Program

Biology

Abstract

The basic helix loop helix transcription factor DIMMED promotes neuroendocrine (NE) peptidergic cell properties in the fruit fly Drosophila melanogaster. It is normally present in ~3% of the neurons of the Drosophila central nervous system (CNS). When dimm is lost, these NE neurons survive, but fail to display their normal peptidergic properties in full quantitative terms. The exact molecular mechanism by which DIMM operates is largely unknown. Likewise, how dimm-positive neurons come to acquire this critical phenotype (high level DIMM expression) is not known. To address this important developmental question, I characterized dimm cis-regulatory elements that dictate where and when the gene is transcribed. To do this, I partitioned a ~5 kb upstream regulatory region upstream into eight overlapping fragments, and performed in vivo P-element transformation. Transgenic flies were generated, stable lines established, and the expression patterns of each line were mapped using the UAS::GAL4 system. These maps demonstrate that subsets of DIMM positive neurons are controlled by different cis-elements – thus implicating differential transcriptional regulation for different subsets of DIMM-expressing NE neurons. My results suggest that the final precise map of DIMM expression reflects the involvement of distributed, redundant, and also repressive mechanisms. Furthermore, I propose that the distributed pattern of dimm transcriptional regulation may be explained in part by the functions of the different DIMM neurons.

Language

English (en)

Advisor/Committee Chair

Paul Taghert