Medicine and Health Sciences | Nervous System
Bristles are mechanosensory organs in the Drosophila peripheral nervous system composed of four cells that adopt different fates and differentiate. These four cells (neuron, shaft, sheath, and socket) arise from a sensory organ precursor (SOP). D-Pax2 is a transcription factor necessary for the development of functional bristle cells, particularly in the differentiation of the sheath and shaft cells. This transcription factor is expressed in all four bristle cells during mitotic phases, but is then restricted to the sheath and the shaft cells during differentiation. D-Pax2 is controlled by a 3.1 KB upstream enhancer region, which can be further divided into two segments that drive early and late expression of D-Pax2 separately. The purpose of the research was to try to find the minimal regions of these enhancer segments that control D-Pax2 expression. Understanding control of D-Pax2 expression may help elucidate the mechanism of control of the mammalian homolog Pax2, which has a role in the urogenital tract, eyes, and possibly in kidney cell differentiation. This research was accomplished by cloning truncated fragments of the enhancer regions into the green fluorescent protein (GFP) reporter plasmid pH-Stinger to create transgenic flies that could be dissected and examined for GFP expression, which could be used as a readout for D-Pax2 expression. Drosophila nota were then stained with an anti-D-Pax2 primary antibody, which was detected with a secondary red fluorescence antibody. A fluorescence microscope was used to examine the occurrence of GFP in relation to D-Pax2 protein, and images were taken. Expression of GFP in fly lines bearing proximal, early enhancer fragments and distal, late enhancer fragments was greatly reduced as compared to the controls. The distal, early enhancer fragment showed a similar expression pattern to the control. It was found that this 700 BP segment was sufficient in driving early expression of D-Pax2.
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Kirby, Conor OMS-I and Kavaler, Joshua, "Early Expression of D-Pax2 in Drosophila Sense Organs is Controlled by a 700 Base Pair Cis-Regulatory Region" (2016). MU-COM Research Day. 30.