UC Riverside

The Drosophila olfactory system is an ideal model for the investigation of

principles of gene regulation in the nervous system. Within this system, we characterize

gene expression changes in response to short-term and long-term exposure to odorants.

Additionally, we examine the contributions of two transcription factors to the

development of this chemosensory system. Short-term exposure to odorants and light

leads to neural activation and induction of activity regulated genes (ARGs). ARG

induction in neurons in can lead to long-term changes at the level of the synapse. Such

alterations in synaptic structure/function are thought to underlie important cellular

processes such as synaptic plasticity and long-term memory formation. We have

conducted a genome-wide study of genes in the Drosophila central nervous system

induced after brief periods of sensory stimulation and have identified 352 genes whose

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expression increases in response to neural activity. The regulation of these genes is

altered with increasing age. Furthermore, we demonstrate that loss of a histone

deacetylase alters neuronal response to sensory stimuli, suggesting a mechanism of

epigenetic regulation. We extended our transcriptome analysis to the fly antenna and

found that the genes increased in response to fruit odorants differ significantly from the

genes induced by the repellent DEET. In response to long-term exposure to the odorant

diacetyl, we find that dramatic changes in gene expression can, in part, be attributed to

inhibition of histone deacetylases. This non-traditional action of diacetyl slows

neurodegeneration in the fly model for Huntington’s Disease. We conclude with an

analysis of two transcription factors acj6 and pdm3 and find they regulated proper

chemosensory receptor and axon guidance gene expression in the developing

Drosophila olfactory system.