| Popis: |
Heat shock proteins are known not only to function in stress response but also to participate in various developmental activities of the cell. Hsp90 of Drosophila has been shown to be required for spermatogenesis, since a hypomorphic allele of the hsp83 gene, hsp8308445, is male sterile with all stages requiring microtubule functions being affected. But the role of Hsp90 in actin dynamics during male germ cell development has not been investigated so far. We have extended the studies on the hsp83 08445 allele, and show that the sperm flagella are fragile and loosely packed in this allele, and the actin cone assembly and progression during individualization of sperms are badly affected. Further, sperm nuclei are misshapen and not embedded in the F-actin extensions of the head cyst cells, resulting in loss of their alignment and retention at the base of the testis. Thus, our data indicates a critical role for Hsp90 in actin dynamics during sperm individualization. We also provide a comprehensive account of the LacZ reporter gene activity associated with the hsp8308445 allele in comparison to the wild type Hsp90 distribution in various larval and adult tissues. Furthermore, we report an important observation that the chromatin of somatic cyst cells of testis is structured in a characteristic fashion as visualized by DAPI staining, which can be conveniently used as a specific marker for this cell type, eliminating the need for a marker antibody. |
