Title

Taking a knockout approach to study the functions of small heat shock protein family in Drosophila melanogaster

Date of Completion

January 2009

Keywords

Biology, Genetics

Degree

Ph.D.

Abstract

Small Heat Shock Proteins (sHsps) belong to a molecular chaperon family that is involved in stress resistance through preventing irreversible aggregation of the denatured proteins. They work together with other molecular chaperon families such as Hsp70s and Hsp60s in stress resistance, although their mechanism of functioning is not well understood. In Drosophila melanogaster, there are four major shsp genes. They cluster in the 67B polytene region on the third chromosome. In this study, we used a knockout approach to generate series of deficiencies in the shsp gene region, and studied the in vivo functions of the shsp genes both under regular laboratory conditions and under environmental stresses such as heat, starvation, and oxidation. The results showed that the functions of sHsps are pleiotropic and additive. Flies lacking the shsp genes showed defects under heat, starvation or oxidative treatment, and the defects were more severe in larger shsp deficiencies that simultaneously removed multiple shsp genes. In addition, while all the shsp genes contribute to the fitness of the flies, they showed specificities in mitigating specific stress conditions. As this is the first time a series of deficiencies were generated for the shsp genes, this study greatly improves our understanding on the working mechanisms of the shsp genes.^