GFP markers for studying D. melanogaster spermatogenesis

Localization of a set of chimeric GFP proteins in D. melanogaster spermatogenesis has been studied. In the collection used, the proteins with detectable germ-line expression frequently occur to be involved in mRNA maturation. According to the cellular localization, proteins fall into three groups, namely, the protein Rtc1, involved in splicing, displays an exclusively nuclear localization; the proteins Squid (splicing and mRNA transport), Pabp2 (polyadenylation), and Hrb98DE (splicing and mRNA transport) change their localization during germ-line development; and the protein Imp (mRNA localization) is located exclusively in the cytoplasm. The distribution of Rtc1, Squid and Hrb98DE in the spermatocyte nuclei is morphologically similar to the distribution of splicing bodies, the so-called splicing factor compartments. The proteins Imp and Hrb98DE at the stage of elongation are localized to a specialized structure in the caudal region of cyst; this region corresponds to the site of the highest synthetic activity in the cyst cells at this developmental stage.