Project description:TRAP performed in GFP-RPL10A Min6 cells transfected with siRNA targeting Pdx1 or a non-targeting (NT) control. IP RNA was isolated by TRAP protocol and input lysate was used to isolate Total RNA. RNA-seq was performed on both IP and Total RNA.
Project description:We applied TRAP-seq to adult flies expressing GFP tagged Rpl10 in the glial cells (with Repo-Gal4) to look for genes whose translation are affect at different time points after recieving TBI
Project description:In adult gonads, disruption of somatic sexual identity leads to defective gametogenesis and infertility. However, the underlying mechanisms by which somatic signals regulate germline cells to achieve proper gametogenesis remain unclear. In our previous study, we introduced the chinmoSex Transformation (chinmoST ) mutant Drosophila testis phenotype as a valuable model for investigating the mechanisms underlying sex maintenance. In chinmoST testes, depletion of the Janus Kinase-Signal Transducer and Activator of Transcription downstream effector Chinmo from somatic cyst stem cells (CySCs) feminizes somatic cyst cells and arrests germline differentiation. Here, we use single-cell RNA sequencing to uncover chinmoST -specific cell populations and their transcriptomic changes during sex transformation. Comparative analysis of intercellular communication networks between wild-type and chinmoST testes revealed disruptions in several soma-germline signaling pathways in chinmoST testes. Notably, the insulin signaling pathway exhibited significant enhancement in germline stem cells (GSCs). Chinmo cleavage under targets and tagmentation (CUT&Tag) assay revealed that Chinmo directly regulates two male sex determination factors, doublesex (dsx) and fruitless (fru), as well as Ecdysone-inducible gene L2 (ImpL2), a negative regulator of the insulin signaling pathway. Further genetic manipulations confirmed that the impaired gametogenesis observed in chinmoST testes was partly contributed by dysregulation of the insulin signaling pathway. In summary, our study demonstrates that somatic sex maintenance promotes normal spermatogenesis through Chinmo-mediated conserved sex determination and the insulin signaling pathway. Our work offers new insights into the complex mechanisms of somatic stem cell sex maintenance and soma-germline communication at the single-cell level. Additionally, our discoveries highlight the potential significance of stem cell sex instability as a novel mechanism contributing to testicular tumorigenesis.
Project description:899685-899687: use GFP-nAb to co-IP from naive ARPE-HPV cells; 899688-899690: use GFP-nAb to co-IP from ARPE-HPV cells that stably express AP2-Alpha-eGFP.
Project description:The successful segregation of germ cells from somatic lineages is vital for sexual reproduction and species survival. In the mouse, primordial germ cells (PGCs), precursors of all germ cells, are induced from the post-implantation epiblast. Induction requires BMP4 signalling to prospective PGCs and the intrinsic action of PGC transcription factors (TFs). However, the molecular mechanisms connecting BMP4 action to induction of PGC TFs that are responsible for segregation of PGCs from somatic lineages are unknown. Here we show that the transcription factor OTX2 is a key regulator of these processes. Down-regulation of Otx2 precedes the initiation of the PGC programme both in vitro and in vivo. Deletion of Otx2 in vitro dramatically increases PGCLC differentiation efficiency and prolongs the period of PGC competence. In the absence of Otx2 activity, PGCLC differentiation becomes independent of the otherwise essential cytokine signals, with germline entry initiating even in the absence of the PGC TF Blimp1. Deletion of Otx2 in vivo increases PGC numbers. These data demonstrate that Otx2 acts repressively upstream of PGC TFs and functions as a roadblock to prevent the untimely entry of pluripotent stem cells into the PGC lineage, thereby ensuring correct spatio-temporal segregation of the germline and soma.
Project description:In Drosophila melanogaster embryos, somatic versus germline identity is the first cell fate decision. Zygotic genome activation (ZGA) orchestrates regionalized gene expression, imparting specific identity on somatic cells. ZGA begins with a minor wave that commences at nuclear cycle (NC)8 under the guidance of chromatin accessibility factors (Zelda, CLAMP, GAF), followed by the major wave during NC14. By contrast, primordial germ cell (PGC) specification requires maternally deposited and posteriorly anchored germline determinants. This is accomplished by a centrosome coordinated release and sequestration of germ plasm during the precocious cellularization of PGCs in NC10. Here, we report a novel requirement for Zelda and CLAMP during the establishment of the germline/soma distinction. When their activity is compromised, PGC determinants are not properly sequestered, and specification is disrupted. Conversely, the spreading of PGC determinants from the posterior pole adversely influences transcription in the neighboring somatic nuclei. These reciprocal aberrations can be correlated with defects in centrosome duplication/separation that are known to induce inappropriate transmission of the germ plasm. Interestingly, consistent with the ability of bone morphogenetic protein (BMP) signaling to influence specification of embryonic PGCs, reduction in the transcript levels of a BMP family ligand, decapentaplegic (dpp), is exacerbated at the posterior pole.
Project description:During the evolution of heteromorphic sex chromosomes, the sex-specific Y chromosome degenerates, while the X chromosome evolves new mechanisms of regulation. Using bioinformatic and experimental approaches, we investigate the expression of the X chromosome in Drosophila melanogaster. We observe nearly complete X chromosome dosage compensation in male somatic tissues, but not in testis. The X chromosome contains disproportionately fewer genes with high expression in testis than the autosomes, even after accounting for the lack of dosage compensation, which suggests that another mechanism suppresses their expression in the male germline. This is consistent with studies of reporter genes and transposed genes, which find that the same gene has higher expression when autosomal than when X-linked. Using a new reporter gene that is expressed in both testis and somatic tissues, we find that the suppression of X-linked gene expression is limited to genes with high expression in testis and that the extent of the suppression is positively correlated with expression level.
Project description:We report the enrichment of mRNAs with motor neuron specific TDP-43 and tagged ribosomes in control as well as multiple models of TDP-43 induced neurodegeneration. Amyotrophic lateral sclerosis (ALS) is a genetically heterogeneous neurodegenerative disease in which 97% of patients exhibit cytoplasmic aggregates containing the RNA binding protein TDP-43. The goal of this study is to understand the translational consequences of TDP-43 pathology. Using the GAL4-UAS system, we expressed TDP-43WT and TDP-43G298S in the motor neurons of our drosophila to induce ALS-like neurodegeneration. TDP-43 was immunoprecipitated from the larvae at the 3rd instar stage; TDP-43 associated mRNAs, the whole larvae input, and ventral nerve cords of the same genotype were then sequenced. To identify translational changes we conducted TRAP (translating ribosome affinity purifications) in 3rd instar larvae by immunoprecipitating the motor neuron specific tagged ribosomal subunit RpL10-GFP in both ALS models as well as a RpL10-GFP control. The RpL10-GFP associated mRNAs, the whole larval input, and ventral nerve cords of the same genotype. From this data, we identified both compensatory alterations to translation induced by TDP-43 pathology and direct targets of TDP-43 mediated translational inhibition.
Project description:Mouse and human stem cells with features similar to those of embryonic stem cells have been derived from testicular cells. Although pluripotent stem cells have been obtained from defined germline stem cells (GSCs) of mouse neonatal testis, only multipotent stem cells have been obtained so far from defined cells of mouse adult testis. In this study we describe a robust and reproducible protocol for obtaining germline-derived pluripotent stem (gPS) cells from adult unipotent GSCs. Pluripotency of gPS cells was confirmed by in vitro and in vivo differentiation, including germ cell contribution and transmission. As determined by clonal analyses gPS cells indeed originate from unipotent GSCs. We propose that the conversion process requires a GSC culture microenvironment that depends on the initial number of plated GSCs and the length of culture time. Nine samples were analyzed. GSC1: Mouse Germ Stem Cells, line 1 (1 replicate), GSC2: Mouse Germ Stem Cells, line 2 (1 replicate), GSC3: Mouse Germ Stem Cells, line 3 (1 replicate), GSC4: Mouse Germ Stem Cells, line 4 (1 replicate) gPS1: Mouse clonal germ Pluripotent Stem cells, line 1, GFP-sorted (1 replicate), gPS2: Mouse clonal germ Pluripotent Stem cells, line 2, GFP-sorted (1 replicate), gPS3: Mouse clonal germ Pluripotent Stem cells, line 3, GFP-sorted (1 replicate) ESC: Mouse Embryonic Stem Cells (duplicate)