Project description:This series compares gene expression between germ line stem cells (GSCs) purified either from bam mutant or Dpp-overexpressing ovaries, with gene expression in Kc cells Experiment Overall Design: 3 replicates of GSCs from bam mutant ovaries Experiment Overall Design: 3 replicates of GSCs from Dpp overexpressing ovaries Experiment Overall Design: 3 replicates of Kc tissue culture cells
Project description:We characterize the transcriptome of germline stem cell (GSC)-like cells isolated from bag of marbles (bam) mutant Drosophila ovaries by next generation RNA sequencing (RNA-seq) and compare it to the transcriptome of germline cells isolated from wild type ovaries. We further refine this dataset by utilizing an RNA-immunoprecipitation strategy to identify transcripts bound to the master differentiation factor Bam.
Project description:Here, we analyzed two small RNA libraries derived from ovarian tissue mutant for either the Drosophila SETDB1 gene, or the Bam gene. Here we show that deposition of histone 3 lysine 9 by the methyltransferase dSETDB1 (egg) is required for piRNA cluster transcription. In the absence of dSETDB1, cluster precursor transcription collapses in germline and somatic gonadal cells and TEs are activated, resulting in germline loss and a block in germline stem cell differentiation. We propose that heterochromatin protects the germline by activating the piRNA pathway. Keyword : Epigenetics 2 libraries were analyzed, with 1 being a developmental control (Bam Mutant).
Project description:This series compares gene expression between germ line stem cells (GSCs) purified either from bam mutant or Dpp-overexpressing ovaries, with gene expression in Kc cells Keywords: bam mutant, Dpp overexpression
Project description:Histone modifications are a class of epigenetic marks with prominent roles in gene regulation in eukaryotes. One such mark, predominantly inactivation-related, is methylation of histone H3 lysine 9 (H3K9). In the present study, we decipher the interplay between two evolutionary conserved Drosophila H3K9-specific histone methyltransferases, SU(VAR)3-9 and SETDB1. We asked whether SETDB1 is required for targeting of SU(VAR)3-9. Using DamID-seq, we obtained SU(VAR)3-9 binding profiles for the chromosomes from larval salivary glands and germline cells from adult females, and compared profiles between the wild type and SETDB1-mutant backgrounds. Our analyses indicate that the vast majority of single-copy genes in euchromatin are targeted by SU(VAR)3-9 only in the presence of SETDB1, whereas repeated sequences in heterochromatin is largely SETDB1-independent. Interestingly, piRNA clusters 42AB and 38C behave differently in terms of SU(VAR)3-9 binding in somatic and germline cells. Namely, SU(VAR)3-9 binding to these piRNA clusters is independent of SETDB1 in somatic cells, whereas it is SETDB1-dependent in the germline. In addition, we compared SU(VAR)3-9 profiles in female germline cells at different developmental stages (whole juvenile ovaries and mature nurse cells). It turned out that SU(VAR)3-9 binding is influenced both by the presence of SETDB1, as well as by the differentiation stage.
