Elimination of the neuroparsin neuroendocrine cells in Drosophila virilis using the UAS-Gal4 system shows that neuroparsin is not important for reproduction in this species.

Neuroparsin is a common insect neurohormone produced in large neuroendocrine cells in the brain and is important in mosquito reproduction. Although it is present in many flies including many Drosophila species, it was lost from D. melanogaster and a few closely related species. Three different lines of transgenic D. virilis were produced: One that expresses the yeast transcription factor gal4 under the control of the neuroparsin promoter (NP-gal4), while others codes for proteins under the control of the gal4 promoter, either enhanced green fluorescent protein (UAS-eGFP) or the D. virilis ortholog of reaper, an apoptosis inducing protein (UAS-rpr). Crosses between UAS-eGFP and NP-gal4 revealed that expression of NP-gal4 was correct. Crosses between UAS-rpr and NP-gal4 completely eliminated the neuroparsin neuroendocrine cells, but were without effect on reproduction.