Drosophila germline sex determination: integration of germline autonomous cues and somatic signals.

The Drosophila testis and ovary are major genetically tractable systems for studying stem cells and their regulation. This has resulted in a deep understanding of germline stem cell regulation by the microenvironment, or niche. The male and female germline niches differ. Since sex is determined through different mechanisms in the soma than in the germline, genetic or physical manipulations can be used to experimentally mismatch somatic and germline sexual identities. The phenotypic consequences of these mismatches have striking similarities to those resulting from manipulations of signals within the niche. A critical role of the germline sex determination pathway may therefore be to ensure the proper receipt and processing of signals from the niche.