Project description: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.
Project description:Drosophila melanogaster is a well-studied genetic model organism with several large-scale transcriptome resources. Here we investigate 7,952 proteins during the fly life cycle from embryo to adult and also provide a high-resolution temporal time course proteome of 5,458 proteins during embryogenesis. We use our large scale data set to compare transcript/protein expression, uncovering examples of extreme differences between mRNA and protein abundance. In the embryogenesis proteome, the time delay in protein synthesis after transcript expression was determined. For some proteins, including the transcription factor lola, we monitor isoform specific expression levels during early fly development. Furthermore, we obtained firm evidence of 268 small proteins, which are hard to predict by bioinformatics. We observe peptides originating from non-coding regions of the genome and identified Cyp9f3psi as a protein-coding gene. As a powerful resource to the community, we additionally created an interactive web interface (http://www.butterlab.org) advancing the access to our data.