The focus of my research is to understand the developmental signals that are required to regulate cell proliferation. To this end, I have been studying a gene, roughex (rux), that is required to arrest cells in G1 in the developing compound eye of Drosophila. Genetic and biochemical interactions suggest that rux is acting as a cyclin kinase inhibitor, a new class of proteins recently identified in both yeast and mammalian systems. Due to the extremely dosage-sensitive nature of the rux mutant phenotype, this mutation has provided a unique opportunity to identify genetically novel components that are necessary to arrest cell cycle progression in response to developmental signals. Current efforts are directed towards the phenotypic characterization and molecular cloning of these genes. The high degree of homology of cell cycle regulators between species suggests that the pathways for G1 regulation will be highly conserved throughout evolution, and that the analysis of these pathways in Drosophila will be directly applicable to the understanding of cell cycle regulation in higher eukaryotes.
Thomas, B. J., Gunning, D. A., and Zipursky, S. L. 1994. Cell cycle progression in the developing Drosophila eye: roughex encodes a novel protein required for the establishment of G1. Cell 77: 1003-1014.
Gonczy, P., Thomas, B. J., and DiNardo, S. 1994. roughex is a dose-dependent regulator of the second meiotic division during Drosophila spermatogenesis. Cell 77: 1015-1025.
Thomas, B. J. and Zipursky, S. L. 1994. Early pattern formation in the developing Drosophila eye. Trends Cell Biol. 4: 389-394.
Finley, R. L., Jr., Thomas, B. J., Zipursky, S. L., and Brent, R. (1996). Isolation of Drosophila cyclin D, a protein expressed in the morphogenetic furrow before entry into S phase. Proc. Natl. Acad. Sci. USA in press.
A postdoctoral position is currently available to study mechanisms of cell cycle regulation during eye development. Recent efforts are directed towards the developmental and molecular characterization of novel loci that interact genetically with roughex, a gene required for G1 arrest during eye
development. Please direct inquiries to: Barbara Thomas