Project description:In this study, we employed a combination of RIP-seq and short- and long-wave iCLIP technologies to identify transcripts associated with cytoplasmic RNPs containing the RNA-binding protein Drosophila Imp. We also made a Imp knockdown vs luciferase control experiment. Two biological iCLIP-seq, as well as two mRNAseq made on cells harvested on the same day. Two biological PAR-iCLIP-seq. Two biological RIP-seq, as well as two mRNAseq made on cells harvested on the same day. Three biological mRNAseq of imp dsRNA treated cells as well as three control mRNAseq of cells treated with Luciferase dsRNA.
Project description:In this study, we employed a combination of RIP-seq and short- and long-wave iCLIP technologies to identify transcripts associated with cytoplasmic RNPs containing the RNA-binding protein Drosophila Imp. We also made a Imp knockdown vs luciferase control experiment.
2015-05-27 | GSE62997 | GEO
Project description:RNA-seq of Drosophila melanogaster: adult brain synaptosome
Project description:The numerous neurons and glia that form the brain originate from tightly controlled growth and division of neural stem cells, regulated systemically by known extrinsic signals. However, the intrinsic mechanisms that control the characteristic proliferation rates of individual neural stem cells are unknown. Here, we show that the size and division rates of Drosophila neural stem cells (neuroblasts) are controlled by the highly conserved RNA binding protein Imp (IGF2BP), via one of its top binding targets in the brain, myc mRNA. We show that Imp stabilises myc mRNA leading to increased Myc protein levels, larger neuroblasts, and faster division rates. Declining Imp levels throughout development limit myc mRNA stability to restrain neuroblast growth and division, while heterogeneous Imp expression correlates with myc mRNA stability between individual neuroblasts in the brain. We propose that Imp-dependent regulation of myc mRNA stability fine-tunes individual neural stem cell proliferation rates.
Project description:Adult stem cells support tissue homeostasis and repair throughout the life of an individual. However, numerous intrinsic and extrinsic changes occur with age that result in altered stem cell behavior and reduced tissue maintenance and regeneration. In the Drosophila testis, stem cells surround and contact the apical hub, a cluster of somatic cells that express the self-renewal factor Unpaired (Upd), which activates the JAK-STAT pathway in adjacent stem cells. However, aging results in a dramatic decrease in upd expression, with a concomitant loss of germline stem cells (GSCs). Here we present genetic and biochemical data to demonstrate that IGF-II mRNA binding protein (Imp) counteracts endogenous small interfering RNAs to stabilize upd RNA and contribute to maintenance of the niche. However, Imp expression decreases in hub cells of older males, similar to upd, which is due to targeting of Imp by the heterochronic microRNA let-7. Therefore, in the absence of Imp, upd mRNA becomes unprotected and susceptible to degradation. Understanding the mechanistic basis for aging-related changes in stem cell behavior will lead to the development of strategies to treat age-onset diseases and facilitate stem cell based therapies in older individuals. Examination of small RNA levels in testes from young (1day old) and aged (30days old) males of Drosophila melanogaster by deep sequencing (using Illumina GAII).
Project description:microRNAs (miRNAs) are a class of small non-coding RNAs involved in the coordination and/or fine-tuning of gene expression. As such, miRNAs are thought to be critical cis-acting regulatory factors that control a wide range of physiological processes in the brain. The datasets presented here represent the miRNA transcriptome of the adult and larval Drosophila melanogaster CNS as determined by small RNA deep sequencing (RNA-Seq). They were derived from adult and larval samples explanted from the animal that contain minimal extraneous (non-neuronal) tissues. Here we present a concise summary of our profiling results as well as the original sequencing data. We identify many miRNAs that are expressed at equal levels in both tissues and several that are significantly enriched in the larval and adult brain. Some of these belong to miRNA families with conserved members in mammals. These datasets should provide a good starting point for others interested in characterizing miRNAs with putative functions in Drosophila neurons. The datasets presented here represent the miRNA transcriptome of the adult and larval Drosophila melanogaster CNS as determined by small RNA deep sequencing (RNA-Seq).
Project description:The temporal patterning of neural stem cells is a powerful mechanism to generate neural diversity. In Drosophila, the progression of post-embryonic neurogenesis is driven by RNA-binding proteins Imp (IGF2BP) and Syp (SYNCRIP), however how they achieve their function is not well understood, since little is known about their RNA targets in the brain. Here, we present comprehensive RNA interactomes of Imp and Syp at different time points during larval brain development. Imp and Syp target highly overlapping sets of mRNAs whose encoded proteins impact fate specification, stem cell maintenance and tumourigenesis. Within these transcripts, Imp and Syp footprints exhibit limited overlap, instead we show their binding sites have co-evolved, suggesting a combinatorial or cooperative mode of regulation rather than competitive binding. Further, we identify RNAs dynamically interacting with Imp/Syp across development, consisting of existing and potentially new candidates of the neurogenesis program, and loss of Imp or Syp disrupts expression of key transcripts denotative of early or late-born neurons. Together, our findings highlight a post-transcriptional regulatory network that influences temporal order, and our study is a valuable resource for future studies finely-dissecting molecular mechanisms of neuronal fate specifications.