Project description:One of the histone modifications involved in gene silencing is H3K9 methylation, which is found in the chromosomes across different eukaryotes and controlled by SU(VAR)3-9 and its orthologs. Although SU(VAR)3-9 was discovered over two decades ago, little is known about the details of its chromosomal distribution pattern and effect on gene regulation during germ cells development. To fill in this gap, we used RNA-Seq approach to investigate the effect of Su(var)3-9 mutation on gene expression during Drosophila spermatogenesis. Overall design: RNA-Seq gene expression profiling in Su(var)3-9-mutant and wild-type testes of Drosophila melanogaster. Biological replicates were performed for each sample.
Project description:Histone modifications represent one of the key factors contributing to proper genome regulation. One of the histone modifications involved in gene silencing is H3K9 methylation, which is found in the chromosomes across different eukaryotes and controlled by SU(VAR)3-9 and its orthologs. Although SU(VAR)3-9 was discovered over two decades ago, little is known about the details of its chromosomal distribution pattern. To fill in this gap, we used DamID-seq approach and obtained high-resolution genome-wide profiles for SU(VAR)3-9 in two somatic and two germline tissues of fruitfly. Overall design: DamID-Seq profiling of Su(var)3-9 protein in somatic and germline cells of Drosophila melanogaster. We performed DamID profiling of Su(var)3-9 in male (M) and female (F) salivary glands (SG), larval brains (BR), germline nurse cells (NC) and at the different developmental stages of male germ cells, using testes of bam-, aly-, can-mutants and wild-type testes. For every experiment Dam-alone control was performed. Experiments were performed in replicates.
Project description:Heterochromatin protein 1a (HP1a) is a chromatin associated protein that has been well studied in many model organisms, such as Drosophila, where it is a determining factor for classical heterochromatin. HP1a is associated with the two histone methyltransferases SETDB1 and Su(var)3-9, which mediate H3K9 methylation marks and participate in the establishment and spreading of HP1a enriched chromatin. While HP1a is generally regarded as a factor that represses gene transcription, several reports have linked HP1a binding to active genes, and in some cases, it has been shown to stimulate transcriptional activity. To clarify the function of HP1a in transcription regulation and its association with Su(var)3-9, SETDB1 and the chromosome 4 specific protein POF, we conducted genome-wide expression studies and combined the results with available binding data in Drosophila melanogaster. The results suggested that HP1a has a repressing function on chromosome 4, where it preferentially targets non-ubiquitously expressed genes (NUEGs), and a stimulating function in pericentromeric regions. Further, we showed that the effects of SETDB1 and Su(var)3-9 are similar to HP1a, and on chromosome 4, Su(var)3-9, SETDB1 and HP1a target the same genes. In contrast, transposons are repressed by HP1a and Su(var)3-9 but are un-affected by SETDB1 and POF. In addition, we found that the binding level and expression effects of HP1a are affected by gene length. Our results indicate that genes have adapted to be properly expressed in their local chromatin environment. We prepared total RNA from 1st instar larvae trans-heterozygous for HP1a04/HP1a05, trans-heterozygous Su(var)3-9evo/Su(var)3-906, homozygous Setdb110.1/ Setdb110.1 mutants and trans-heterozygous HP1a04 PofD119/HP1a05 PofD119 double mutants three biological replicates, as well as from six biological replicates of wildtype control 1st instar larvae.
Project description:mRNA expression levels were determined by NGS for wildtype larvae as well as for larvae lacking HP1a [Su(var)205^04/Su(var)205^05 transheterozygotes]. RNA samples from wildtype (OR) and HP1a mutant third instar larvae were examined, using duplicate biological samples and Illumina NGS.
Project description:Drosophila imaginal disc cells exhibit a remarkable ability to switch cell fates under various perturbations, a phenomenon known as transdetermination (TD). The winged eye (wge) gene induces eye-to-wing TD by its overexpression in eye imaginal discs using eye specific Gal4 driver (eyeless-Gal4). Gene network controlling this process, however, is largely unclear. Additionally, we identified that heterochromatin-related histone methyltransferase Su(var)3-9 is essential for wge-mediated TD. We used microarray to detail the global gene network underlying wge-mediated eye-to-wing TD, and the involvement of Su(var)3-9 in the gene network. Overall design: Third instar larval eye imaginal discs were dissected for RNA extraction and hybridization on Affymetrix microarray. Flies from each genotype were used (I: eyeless-Gal4, II: UAS-wge, III: ey-Gal4; UAS-wge (ey > wge), IV: ey-Gal4 UAS-wge; Su(var)3-91/Su(var)3-92). Three biologic replicates were obtained for each.
Project description:H3K9 methylation is a mark of inactive chromatin. In D.melanogaster, three enzymes (SU(VAR)3-9, EGG, and dG9A) are responsible for creating the H3K9 methyl mark. We have investigated the effects of loss of SU(VAR)3-9 and EGG on gene expression in adult heads using microarray analysis. Keywords: Expression profiling by microarray Overall design: Heads from adults flies were used for RNA extraction and hybridization on Affymetrix microarrays. Four genotypes were used: yw; +/CyO, yw; egg235/CyO, yw; +/CyO; Su(var)3-906; yw; egg235/CyO; Su(var)3-906. For each genotype, three biological replicates were analyzed. For the yw; +/CyO control, an additional technical replicate (same RNA sample processed twice) is included. While source files for both technical replicates are included, only one was used for the final analysis.