Ruolo della proteina ORY nella spermiogenesi in Drosophilamelanogaster

Unlike humans and other placental mammals, in which masculinity is due to a dominant effect of the Y chromosome, this chromosome in Drosophila melanogaster does not play any role in sex determination, which is determined by the ratio of X chromosomes and autosomal arrangements. An X0 individual is, in fact, male but sterile demonstrating that the Y chromosome contains genes important for male fertility. Among these has been identified and mapped the gene Ory (AB Carvalho et al., 2001), characterized by a series of coiled-coil motifs contained in molecules such as those of the heavy chains of myosin, with which, however, there is no orthology. After gene Ory silencing, males of Drosophila m. have infertility as a primary phenotype. In this work we also examined the role that the protein ORY might have in the sperm formation. TEM analysis of the mutant testes showed a series of morphological changes during spermiogenesis in varying degrees, in particular changes are evident in the development stages of spermatids after post-elongation; these spermatids, in fact, came to the stage of individualization but did not differentiate in mature sperm. The following CLSM analysis has also highlighted that the investment cones, individualization actinic-based structures, were not moving correctly along the axonemes of spermatids, remaining associated with the base of the nuclei of cells in elongation. So it appears that the protein ORY is involved in proper progress of the individualization complex during spermiogenesis. It remain to be clarified the proteins and the manner in which ORY interacts in individualization complex and understand the molecular mechanism that allows it to intervene in the advancement of the cones.