The free-living nematode, Caenorhabditis elegans, is one of the best-characterized metazoans and it is amenable to many of the most powerful genetic technologies available. It is, therefore, an appropriate experimental organism for the study of many developmental processes, including meiosis. There are a number of cytological differences between male and female meiosis. In male meiosis, spermatocytes normally undergo two equal divisions leading to the formation of four spermatids. In females, on the other hand, the meiocytes undergo unequal cell division leading to the formation of an ovum and the polar bodies. The biochemical basis for these differences is not known. Several mutation screens have identified a large number of mutants defective in spermatogenesis. Morphological characterization of these mutants led to the identification of a group with defective primary spermatocytes that failed to complete meiotic division. The mutants fall into ten different complementation groups (early acting Spe genes). The specific aims for this proposal are to genetically, phenotypically and molecularly characterize the spe-25 gene, a gene which preliminary characterization suggests is one of the earliest acting Spe genes. It has been mapped to a well-characterized region of chromosome III that should optimize the molecular characterization.
The analysis of these genes in a model organism will enhance our knowledge of the male specific meiotic event in a metazoan organism. Moreover, the proposed experiments are particularly suited for the involvement of undergraduate students in a "hands-on" laboratory environment.
