The Hox gene Abd-B controls stem cell niche function in the Drosophila testis
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ABSTRACT:
ORGANISM(S): Drosophila melanogaster
PROVIDER: GSE53709 | GEO | 2013/12/30
SECONDARY ACCESSION(S): PRJNA232693
REPOSITORIES: GEO
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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:The Piwi-piRNA pathway is well known for its germline function, yet its somatic role remains elusive. We show here that Piwi is required autonomously not only for germline stem cell (GSC) but also for somatic cyst stem cell (CySC) maintenance in the Drosophila testis. Reducing Piwi activity in the testis caused defects in CySC differentiation. Accompanying this, GSC daughters expanded beyond the vicinity of the hub but failed to differentiate further. Moreover, Piwi deficient in nuclear localization caused similar defects in somatic and germ cell differentiation, which was rescued by somatic Piwi expression. To explore the underlying molecular mechanism, we identified Piwi-bound piRNAs that uniquely map to a gene key for gonadal development, Fasciclin 3, and demonstrate that Piwi regulates its expression in somatic cyst cells. Our work reveals the cell-autonomous function of Piwi in both somatic and germline stem cell types, with somatic function possibly via its epigenetic mechanism. Examination of Piwi-piRNAs in fly testis
2015-05-23 | E-GEOD-68997 | biostudies-arrayexpress
Project description:The Hox gene Abd-B controls stem cell niche function in the Drosophila testis
| PRJNA232693 | ENA
Project description:The Piwi-piRNA pathway is well known for its germline function, yet its somatic role remains elusive. We show here that Piwi is required autonomously not only for germline stem cell (GSC) but also for somatic cyst stem cell (CySC) maintenance in the Drosophila testis. Reducing Piwi activity in the testis caused defects in CySC differentiation. Accompanying this, GSC daughters expanded beyond the vicinity of the hub but failed to differentiate further. Moreover, Piwi deficient in nuclear localization caused similar defects in somatic and germ cell differentiation, which was rescued by somatic Piwi expression. To explore the underlying molecular mechanism, we identified Piwi-bound piRNAs that uniquely map to a gene key for gonadal development, Fasciclin 3, and demonstrate that Piwi regulates its expression in somatic cyst cells. Our work reveals the cell-autonomous function of Piwi in both somatic and germline stem cell types, with somatic function possibly via its epigenetic mechanism.
2015-05-23 | GSE68997 | GEO
Project description:The importance of the niche to provide regulatory inputs to balance stem cell self-renewal and differentiation has become clear. However, the regulatory interplay between stem cells and their niche at the whole genome level is still poorly understood. To elucidate the mechanisms controlling stem cells and their progenies as they progress through development at the transcriptional level, we recorded the regulatory program of two independent cell lineages in the Drosophila testis. We identified genes active in the soma or germline as well as genome-wide binding profiles of two transcription factors, Zfh-1 and Abd-A, expressed in somatic support cells and crucial for fate acquisition of both cell lineages. In order to uncover gene activities in the testis soma, we first determined the transcriptome of the somatic and germline lineages by RNA polymerase II Targeted DamID (TaDa) (Southall et al., 2013), followed by the identification of genes bound by two regulators active in somatic sub-populations and controlling their development using regular DNA adenine methyltransferase identification (DamID) (Van Steensel et al., 2001). For identifying abd-A and Zfh1 binding regions in the Drosophila testis the fusion protein was expressed from the uninduced minimal Hsp70 promoter of the UAS vector pUAST. As a control for nonspecific Dam activity, transgenic flies expressing the Dam alone were used (Choksi et al., 2006). To express the AbdA-Dam fusion protein, we first generated a pNDam-Myc-abdA construct by cloning abdA in the pNDam-Myc vector (van Steensel et al., 2001) and then subcloned the NDam-Myc-abdA fragment into the pUAST-attB and to express the Zfh1-Dam fusion protein, we first generated a pNDam-Myc-zfh1 construct by cloning zfh1 in the pNDam-Myc vector (van Steensel et al., 2001) and then subcloned the NDam-Myc-zfh1 fragment into the pUAST-attB. For targeted DamID (TaDa) in Drosophila 3rd instar testes cyst and germline cells. Cell-type specific DamID was performed in cyst cells (CySCs and SCCs) and early germline of 3rd instar larval testes for profiling RNA Pol II occupancy in these cells by crossing UAS-LT3-Dam-Pol II and UAS-LT3-Dam control flies to c587-GAL4 (somatic lineage) or Nanos-GAL4 (early germline) drivers. For Dam-ID two individual replicates of Dam-abd-A, Dam-Zfh1 and Dam alone have been generated whereas for TaDa, two individual replicates of c587>UAS-LT3-Dam-PolII, Nanos>UAS-LT3-Dam-Pol II and c587>UAS-LT3-Dam (control), Nanos>UAS-LT3-Dam (control) have been used. Following a methylation-sensitive DNA digestion and PCR amplification, DNA fragments from the above samples were labeled and hybridized to genomic Affymetrix arrays in duplicates (Protocol available at “www.flychip.org.uk”).
2018-07-30 | GSE117833 | GEO
Project description:The niche controls stem cell self-renewal and progenitor differentiation for maintaining adult tissue homeostasis in various organisms. However, it remains unclear if the niche is compartmentalized to control stem cell self-renewal and stepwise progeny differentiation. In the Drosophila ovary, inner germarial sheath (IGS) cells form a niche for controlling germline stem cell (GSC) progeny differentiation. In this study, we have identified four IGS subpopulations, which form linearly arranged niche compartments for controlling GSC maintenance and multi-step progeny differentiation. Single-cell analysis of the adult ovary has identified four IGS subpopulations (IGS1-4), which identities and cellular locations have been further confirmed by fluorescent in situ hybridization. IGS1 and IGS2 physically interact with GSCs and mitotic cysts to control GSC maintenance and cyst formation, respectively, whereas IGS3 and IGS4 physically interact with 16-cell cysts to regulate meiosis and oocyte development. Finally, one follicle cell progenitor population has also been transcriptionally defined for facilitating future studies on follicle stem cell regulation. Therefore, this study has structurally revealed that the niche is organized into multiple compartments for orchestrating stepwise adult stem cell development, and has also provided useful resources and tools for further functional characterization of the niche in the future.
2020-12-23 | GSE143817 | GEO
Project description:Abstract: During Drosophila oogenesis, germline stem cell (GSC) identity is maintained largely by preventing the expression of factors that promote differentiation. This is accomplished via the activity of several genes acting either in the GSC or its niche. The translational repressors, Nanos and Pumilio, act in GSCs to prevent differentiation, likely by inhibiting translation of early differentiation factors, while niche signals prevent differentiation by silencing transcription of the differentiation factor Bam. We have found that the DNA-associated protein Stonewall (Stwl) is also required for GSC maintenance. stwl is required cell-autonomously; clones of stwl- germ cells were lost by differentiation, and ectopic Stwl caused an expansion of GSCs. stwl mutants acted as Suppressors of Variegation, indicating stwl normally acts in chromatin-dependent gene repression. In contrast to several previously described GSC maintenance factors, Stwl likely functions epigenetically to prevent GSC differentiation. Stwl-dependent transcriptional repression does not target bam, but rather Stwl represses the expression of many genes, including those that may be targeted by Nanos/Pumilio translational inhibition. Experiment Overall Design: Genetic variation comparison between germ cells of Drosophila ovaries from bam mutant and stwl bam double mutant females. Six total samples were analyzed, with each genotype performed in triplicates.
2008-03-13 | E-GEOD-6928 | biostudies-arrayexpress
Project description:Glioma initiating/stem cells (GIC/GSC) are considered responsible for the therapeutic resistance and recurrence of malignant glioma. To clarify the molecular mechanism of GIC/GSC maintenance/differentiation, we established GIC/GSC clones, having the potential to differentiate into malignant gliomas, from glioblastoma patient’s tissues, and subjected to DNA microarray/iTRAQ based integrated proteomics. 21,857 mRNAs and 8,471 proteins were identified and integrated into a gene/protein expression analysis chart (iPEACH). The data integration and extraction of global proteins and mRNAs revealed that, during the GIC/GSC differentiation, cell adhesion molecules including integrin aV/ECMs and RAS-MAPK/PI3K signalings were significantly up-regulated, meanwhile, SOX2, CD133, and specific proteoglycans/synthetic-enzymes/metabolic pathways were obviously down-regulated. Among them, we focused proteoglycans and their synthetic-enzymes. GIC/GSC differentiation was significantly associated with the decrease of CSPG (CS-modified form) and dramatically induced by the CS-degradation enzyme which also induces the up-regulation of ERK-AKT signaling and GFAP without any other agents. Importantly, these differentiation processes were also associated with the interaction of CSPG (CS-unmodified form) and integrin-aV, and suppressed by integrin-inhibitors/CS administrations significantly. Combination treatments of a cancer-drug Temozolomide and these GIC/GSC-differentiation inhibitors suppressed glioma progression, increased the chemosensitivities, and led the longer survival of mouse xenograft-models. Functional integrated proteomics for the first time demonstrates that the GIC/GSC induces the specific proteoglycans to regulate GIC/GSC stemness/differentiation via the integlin signalings which may be a clinical target against malignant gliomas.
2018-11-30 | PXD008332 | JPOST Repository
Project description:Glioma initiating/stem cells (GIC/GSC) are considered responsible for the therapeutic resistance and recurrence of malignant glioma. To clarify the molecular mechanism of GIC/GSC maintenance/differentiation, we established GIC/GSC clones, having the potential to differentiate into malignant gliomas, from glioblastoma patient’s tissues, and subjected to DNA microarray/iTRAQ based integrated proteomics. 21,857 mRNAs and 8,471 proteins were identified and integrated into a gene/protein expression analysis chart (iPEACH). The data integration and extraction of global proteins and mRNAs revealed that, during the GIC/GSC differentiation, cell adhesion molecules including integrin aV/ECMs and RAS-MAPK/PI3K signalings were significantly up-regulated, meanwhile, SOX2, CD133, and specific proteoglycans/synthetic-enzymes/metabolic pathways were obviously down-regulated. Among them, we focused proteoglycans and their synthetic-enzymes. GIC/GSC differentiation was significantly associated with the decrease of CSPG (CS-modified form) and dramatically induced by the CS-degradation enzyme which also induces the up-regulation of ERK-AKT signaling and GFAP without any other agents. Importantly, these differentiation processes were also associated with the interaction of CSPG (CS-unmodified form) and integrin-aV, and suppressed by integrin-inhibitors/CS administrations significantly. Combination treatments of a cancer-drug Temozolomide and these GIC/GSC-differentiation inhibitors suppressed glioma progression, increased the chemosensitivities, and led the longer survival of mouse xenograft-models. Functional integrated proteomics for the first time demonstrates that the GIC/GSC induces the specific proteoglycans to regulate GIC/GSC stemness/differentiation via the integlin signalings which may be a clinical target against malignant gliomas.
2018-11-30 | PXD008331 | JPOST Repository
Project description:Glioblastoma ranks among the most lethal of primary brain malignancies, with glioblastoma stem cells (GSCs) at the apex of tumor cellular hierarchies. Here, to discover novel therapeutic GSC targets, we interrogated gene expression profiles from GSCs, differentiated glioblastoma cells (DGCs), and neural stem cells (NSCs), revealing EYA2 as preferentially expressed by GSCs. Targeting EYA2 impaired GSC maintenance and induced cell cycle arrest, apoptosis, and loss of self-renewal. EYA2 displayed novel localization to centrosomes in GSCs, and EYA2 tyrosine (Tyr) phosphatase activity was essential for proper mitotic spindle assembly and survival of GSCs. Inhibition of the EYA2 Tyr phosphatase activity, via genetic or pharmacological means, mimicked EYA2 loss in GSCs in vitro and extended the survival of tumor-bearing mice. Supporting the clinical relevance of these findings, EYA2 portends poor patient prognosis in glioblastoma. Collectively, our data indicate that EYA2 phosphatase function plays selective critical roles in the growth and survival of GSCs, potentially offering a high therapeutic index for EYA2 inhibitors.
2021-09-25 | GSE135306 | GEO