Expression of protein tyrosine phosphatase genes during oogenesis in Drosophila melanogaster

The spatial and temporal expression of seven Drosophila protein tyrosine phosphatase genes during oogenesis was examined by whole mount in-situ hybridization of antisense RNA probes to ovaries. Our observations indicate diverse expression patterns consistent with multiple roles for protein tyrosine phosphatases in the ovary. DPTP99A and corkscrew transcripts are expressed in follicle cells, consistent with possible roles in the EGF receptor signaling pathway. Transcripts from corkscrew and DPTP10D are detected in the germline during oogenesis and localized to the oocyte during egg chamber development. Localization of the two transcripts is disrupted by mutations in egalitarian and Bicaudal D. DLAR and DPTP4E transcripts are found in the germline during the same developmental stages as DPTP10D transcripts, but their transcripts are not localized to the oocyte. DPTP61F transcription is detected only after stage 6 of oogenesis. After stage 10B these transcripts are transported to the oocyte; thus ovarian transcription of DPTP61F may reflect a maternal contribution of the mRNA for later use during embryogenesis. DPTP69D transcripts are sequestered in the nucleus from stage 7 to stage 10, and then released to the cytoplasm. Our observations suggest that the export of DPTP69D mRNA from the nucleus is temporally regulated during oogenesis.