PgmNr D1261: Investigating the role of Sox Neuro in the development of adult nervous system.

Authors:
Shweta Singh; Ken Dawson-Scully; John R. Nambu


Institutes
Florida Atlantic University, Biological Sciences, 5353 Parkside Drive, Jupiter FL-33458.


Keyword: CNS

Abstract:

Many aspects of development are controlled through the actions of specific transcription factors that regulate gene expression patterns. The mammalian Sry gene, a sex determining Y chromosome was discovered in 1990 and encodes a transcription factor with single high mobility group DNA binding domain. More than 20 transcription factors in humans and 8 in Drosophila share a related HMG domain with at least 50% identity to that of Sry. These Sox (Sry box) proteins bind to the minor groove of DNA and induce 70° to 90° bends to regulate chromatin structure and transcription initiation. Drosophila possesses 4 highly related Group B Sox genes SoxNeuro, Dichaete, Sox21a and Sox21b. Previous study has shown that Dichaete has a strong role in development, affecting processes that include differentiation of specific neuronal and glial cells, segmentation, hindgut development, differentiation of imaginal discs. Dichaete is expressed in several clusters of neurons in the brain, including intermingled olfactory LNs and central complex neurons and important for the elaboration of the adult olfactory system. SoxN function is important for the formation of neural progenitor cells in Drosophila and evidence suggests that loss of SoxN function results in defects in the neuroblast formation. Interestingly, both SoxN and Dichaete have region-specific functions in CNS development as they both regulate dorsal/ventral partitioning of the embryonic neuroectoderm into specific columns. Evidence also suggests that SoxN and Dichaete function in a redundant manner in neuroblast formation and other developmental processes including neuroectoderm formation, central nervous system development, and sensory trichome formation. However, little is known about the expression and function of SoxN in the adult brain. This study focuses on identifying the expression patterns and function of SoxN in the development of the adult nervous system. Our data shows SoxN is expressed both in neurons and glia of the adult central brain. Interestingly, SoxN expressing neurons are both cholinergic and GABAergic neurons. Our data also suggests role of SoxN in the development of ­­­­­­­­olfactory circuit formation. The result of this study will lead to a better understanding of Sox gene functions in both conserved and specific aspects of development. Sox proteins have essential developmental functions in many species, including key roles in sex determination, segmentation, neural patterning, differentiation of neurons and glia, and formation of eyes, bone, cartilage, heart, and craniofacial structures. Furthermore, Sox gene mutations are associated with a wide array of human congenital disorders and cancer. Thus, these studies on Drosophila Sox genes may illuminate conserved developmental functions in mammals and are relevant for human health.



Flybase Genetic Index:
1. FlyBase gene symbol: SoxN; FBgn: 0029123