Drosophila melanogaster
Ontology highlight
ABSTRACT:
PROVIDER: PRJNA157855 | ENA |
REPOSITORIES: ENA
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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).
2012-05-31 | E-GEOD-37041 | biostudies-arrayexpress
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.
2012-05-31 | GSE37041 | GEO
Project description:The Hox gene Abd-B controls stem cell niche function in the Drosophila testis
| PRJNA232693 | ENA
Project description:Drosophila whole testis gene expression
| PRJNA95035 | ENA
Project description:Stem cells reside in a specialized microenvironment, called niche, which provides essential signals controlling stem cell behavior. Proper niche architecture is a key for normal stem cell function, yet only few upstream regulators are known. Here we report that the Hox transcription factor Abd-B, active in pre-meiotic spermatocytes, affects niche positioning in the Drosophila testis by regulating integrin localization in differentiated somatic cyst cells. Loss of Abd-B results in cell non-autonomous effects within the niche including centrosome misorientation in germline stem cells (GSCs) and reduced GSC divisions in larval testis, leading to a dramatic reduction of pre-meiotic stages in adult testes. By identifying Abd-B binding regions throughout the genome, we find that Abd-B mediates its effects on niche function by directly controlling at multiple levels the localization and thus signaling activity of the Sevenless (Sev) ligand, Bride of Sevenless (Boss), via its direct targets src42A and sec63. In sum, our data show for the first time that Abd-B through local signaling provides positional cues for integrin localization, which is critical for niche localization and architecture, and ensures proper niche function and GSC activity. DamID (DNA adenine methyltransferase identification) method was used to identify direct Abd-B target genes in the Drosophila 3rd instar larval testis
2013-12-30 | GSE53709 | GEO
Project description:Identification and annotation of all the genes in the sequenced Drosophila genome is a work in progress. Wild-type testis function requires many genes and is thus of potentially high value for the identification of transcription units. We therefore undertook a survey of the repertoire of genes expressed in the Drosophila testis by computational and microarray analysis. We generated 3141 high-quality testis expressed sequence tags (ESTs). Testis ESTs computationally collapsed into 1560 cDNA set used for further analysis. Of those, 11% correspond to named genes, and 33% provide biological evidence for a predicted gene. A surprising 47% fail to align with existing ESTs and 16% with predicted genes in the current genome release. EST frequency and microarray expression profiles indicate that the testis mRNA population is highly complex and shows an extended range of transcript abundance. Furthermore, >80% of the genes expressed in the testis showed onefold overexpression relative to ovaries, or gonadectomized flies. Additionally, >3% showed more than threefold overexpression at p <0.05. Surprisingly, 22% of the genes most highly overexpressed in testis match Drosophila genomic sequence, but not predicted genes. These data strongly support the idea that sequencing additional cDNA libraries from defined tissues, such as testis, will be important tools for refined annotation of the Drosophila genome. Additionally, these data suggest that the number of genes in Drosophila will significantly exceed the conservative estimate of 13,601. Keywords: other
2003-07-16 | GSE462 | GEO
Project description:Stem cells reside in a specialized microenvironment, called niche, which provides essential signals controlling stem cell behavior. Proper niche architecture is a key for normal stem cell function, yet only few upstream regulators are known. Here we report that the Hox transcription factor Abd-B, active in pre-meiotic spermatocytes, affects niche positioning in the Drosophila testis by regulating integrin localization in differentiated somatic cyst cells. Loss of Abd-B results in cell non-autonomous effects within the niche including centrosome misorientation in germline stem cells (GSCs) and reduced GSC divisions in larval testis, leading to a dramatic reduction of pre-meiotic stages in adult testes. By identifying Abd-B binding regions throughout the genome, we find that Abd-B mediates its effects on niche function by directly controlling at multiple levels the localization and thus signaling activity of the Sevenless (Sev) ligand, Bride of Sevenless (Boss), via its direct targets src42A and sec63. In sum, our data show for the first time that Abd-B through local signaling provides positional cues for integrin localization, which is critical for niche localization and architecture, and ensures proper niche function and GSC activity. DamID (DNA adenine methyltransferase identification) method was used to identify direct Abd-B target genes in the Drosophila 3rd instar larval testis Dam was fused to the N terminus of Abd-B and transgenic flies were generated. For identifying Abd-B targets in the Drosophila testis the fusion protein was expressed from the uninduced minimal Hsp70 promoter of the UAS vector pUAST (Brand and Perrimon, 1993). As a control for nonspecific Dam activity, transgenic flies expressing the Dam alone were used (Choksi et al., 2006). Subsequently, genomic DNA was extracted from 3rd instar larval testes, expressing either the Dam-Abd-B fusion protein or the Dam protein alone using a specific protocol (Tolhuis et al., 2011); and van Steensel personal communication). Two individual replicates, for Dam-AbdB and Dam alone, have been generated. Following a methylation-sensitive DNA digestion and PCR amplification, DNA fragments from Dam-Abd-B and control DNA were labeled and hybridized to genomic Affymetrix arrays in duplicates (Protocol available at M-bM-^@M-^\www.flychip.org.ukM-bM-^@M-^]).
2013-12-30 | E-GEOD-53709 | biostudies-arrayexpress
Project description:Juvenile hormone regulation of Drosophila aging
| PRJNA208995 | ENA
Project description:We conducted a genome-wide expression analysis of wild-type males using three cell populations isolated from mitotic, meiotic and post-meiotic phases of spermatogenesis in Drosophila melanogaster. Our approach was to directly isolate testis regions enriched with RNAs from each of the three specific germline phases. We used microarrays to detail the global gene expression profile in spermatogenesis and identified up- and down-regulated genes between two different spermatogenic phases in pairwise comparisons Experiment Overall Design: Cell types present at various stages of spermatogenesis are generally located in a gradient along the proximal-distal axis of the testis, however most are not exclusively restricted to any one geographic region. Cells enriched for mitotic, meiotic and post-meiotic phases were obtained by dissection of apical, proximal and distal regions of the testis, respectively
2009-11-28 | E-GEOD-18502 | biostudies-arrayexpress
Project description:Drosophila Imp iCLIP identifies an RNA assemblage co-ordinating F-actin formation
| PRJNA266435 | ENA