ChIP-Seq with Kumgang (Kmg), dMi-2, and Aly from wild-type and kmg KD Drosophila melanogaster testes

Genome wide localization of Kumgang, dMi-2, and Aly in Drosophila melanogaster testes were evaluated by ChIP-Seq in wild-type and kmg knock down testes. / Title: Blocking promiscuous activation at cryptic promoters directs cell type–specific gene expression / Abstract: To selectively express cell type–specific transcripts during development, it is critical to maintain genes required for other lineages in a silent state. Here, we show in the Drosophila male germline stem cell lineage that a spermatocyte-specific zinc finger protein, Kumgang (Kmg), working with the chromatin remodeler dMi-2 prevents transcription of genes normally expressed only in somatic lineages. By blocking transcription from normally cryptic promoters, Kmg restricts activation by Aly, a component of the testis-meiotic arrest complex, to transcripts for male germ cell differentiation. Our results suggest that as new regions of the genome become open for transcription during terminal differentiation, blocking the action of a promiscuous activator on cryptic promoters is a critical mechanism for specifying precise gene activation.