Date of Award

2007

Degree Name

M.S. in Biology

Department

Department of Biology

Abstract

Drosophilids spermtails are considered to be the peacock feathers of the world of sperm, by virtue of their incredible length. This extreme length may be supported by their use of a unique, specialized, testis-specific Beta2 tubulin. Beta2 has a highly stringent structure/function relationship to the Drosophilid spermtail axoneme, such that even small amino acid changes render it non-functional. How then, does this protein evolve, while maintaining is function? We hypothesize that it may need to co-evolve with other axonemal proteins. Here, one and two dimensional gel electrophoresis was used to compare the testes proteomes of several fly species in an attempt to identify axonemal proteins associated with the evolution of Beta2 tubulin, as well as the evolution of the spermtail. First, two-dimensional gel comparison testis proteomes among seven Dipteran/Lepidopteran species led to the discovery of one protein, currently unidentified, that appears to be unique to Drosophilids. This protein was categorized as potentially co-evolving with Beta2. Second, one and two-dimensional gel electrophoresis was conducted on testes from Drosophilid species with short, medium, and long spermtails, in an attempt to identify proteins associated with changes in spermtail length. Two such proteins were identified. The last aim of this project was to develop a rapid screening method for testing the functionality of different genetic constructs in dissected, Drosophilid testes. DNA was transfected by lipofection into testes. Transfection of eGFP DNA resulted in fluorescence. Further, transfection of the Beta2 gene into Beta2 knock-out D. melanogaster testes resulted in the initiation of spermtail growth. In conclusion, upon optimization of experimental conditions, lipofection may be used for functionality testing of various genetic constructs, including the proteins identified by one and two-dimensional gel electrophoresis.

Keywords

Drosophila Genetics, Spermatozoa

Rights Statement

Copyright 2007, author

COinS