In adult stem cell niches, crosstalk between extrinsic cues (such as signals from neighbouring cells) and intrinsic cues (such as chromatin structure) regulates stem cell identity and activity. Now, on , Xin Chen and colleagues report that the histone demethylase dUTX regulates crosstalk among the germline stem cells (GSCs), hub cells and cyst stem cells (CySCs) of the Drosophila testis niche. The researchers show that dUTX acts in CySCs to maintain hub cell identity by activating transcription of the Socs36E gene (which encodes an inhibitor of the JAK-STAT signalling pathway that is required for GSC identity and activity) via removal of a repressive histone modification near its transcription start site. dUTX also acts in GSCs, they report, to maintain hub structure through regulation of DE-cadherin, the Drosophila homologue of vertebrate cadherins. These results show how an epigenetic factor regulates crosstalk among different cell types within an adult stem cell niche and provide important information about the in vivo function of a histone demethylase.
