ABSTRACT: We performed RNA-sequencing of testes derived from Atr+/+ or Atr+/KD 7 weeks old mice. Since Atr+/KD male mice are sterile and present severe spermatogenesis defects, we aimed at analyzing the possible changes in gene expression given by the ATR kinase-dead (KD) mutation
Project description:Background: Production of functional sperms from spermatogonial stem cells in vitro is important for understanding of biological mechanisms underlying physiological spermatogenesis and for treatment of male infertility. However, comparing with the in vivo testes, in vitro spermatogenesis is severely lower efficiency. Here we describe abnormalities occurring in early stage of in vitro spermatogenesis at single cell resolution. Results: While spermatogenesis was similarly progressed between in vivo and in vitro-cultured testes, noticeable acute inflammatory response occurred right after in vitro culture of neonatal testes not only in immune cells but also non-immune testicular somatic cells. Inhibitor treatment revealed NLRP3 inflammasome signaling is key to the inflammation occurring in in vitro cultured testes We also found accumulation of damaged/dead germ cells in in vitro cultured testes, which may be due to dysfunction of sertoli cell phagocytosis. Conclusion: Our data revealed tissue-wide sterile inflammation occurring in in vitro cultured testes, in which DAMPs - NLRP3 inflammasome axis may key element. Thus, these abnormal testicular microenvironments may be a cause of low spermatogenesis efficiency of in vitro spermatogenesis.
Project description:Spermiogenesis in Drosophila melanogaster is a highly conserved process and essential for male fertility. In this haploid phase of spermatogenesis, motile sperm are assembled from round cells, flagella are assembled, and needle-shaped nuclei with highly compacted genomes are formed. We aimed at identifying proteins relevant for the maturation phase from spermatids to sperm. As transcription takes place mainly in spermatocytes, and transcripts with relevance for post-meiotic sperm development are translationally repressed for days, we comparatively analysed the prote-ome of larval testes (stages before meiotic divisions), of testes of 1–2-day-old pupae (meiotic and early spermatid stages) and adult flies (late spermatids and sperm). We identified 6677 pro-teins, with 422 solely detected in larval testes, 623 in pupal testes and 634 in adult testes. We analysed a few so far uncharacterized proteins with repect to stage specific expression and im-portance for male fertility. For example, Mst84B (gene CG1988), a very basic cysteine- and lysine-rich nuclear protein, was present in the phase of transition from a histone-based to a pro-tamine-based chromatin structure. CG6332 encodes d-Theg, which is related to the mouse tHEG and human THEG proteins. Mutants of d-Theg lacked sperm in the seminal vesicles and were sterile. The identification of numerous predicted proteins underscores the high potential of pro-teome analysis for future analyses of spermatogenesis.
Project description:DEAD-box RNA helicases DDX3 are important developmental regulators of multiple aspects of RNA metabolism of eukaryotes. belle, a single DDX3 ortholog in Drosophila, is essential for fly viability, fertility, and germline stem cell maintenance. Here we showed that RNAi belle knockdown in testis cyst cells caused a disruption of adhesion between germ cells and cyst cells and a generation of tumor-like clusters of stem-like germ cells. Ectopic expression of β-integrin in cyst cells rescued early stages of spermatogenesis in the belle knockdown testes, indicating that integrin adhesion complexes are required for interaction between somatic and germ cells in cyst. To address in details Belle functions in spermatogenesis we performed CLIP-seq analysis and identified multiple mRNAs which interacted with Belle in the testes. A set of Belle targets includes mRNAs of factors that are essential for preventing tumor-like cluster formation of early germ cells and ensuring of sustained gametogenesis.
Project description:This dataset represents genes that are dysregulated in the postnatal day 12 (P12) mouse testis when ATRX is specifically inactivated in Sertoli cells (ScAtrxKO mice). The differentially expressed genes included in the dataset may play important roles in the testicular phenotypes observed in the ScAtrxKO mice, which were first reported in our previous work (Bagheri-Fam et al., 2011). In fetal ScAtrxKO mice, Sertoli cells undergo apoptosis due to cell cycle defects, resulting in smaller testes with reduced tubule volume. Adult ScAtrxKO mice show a wide range of spermatogenesis defects probably due to a failure of the dysfunctional ATRX protein to interact with the androgen receptor (AR). The chromatin remodeling protein ATRX is widely expressed in the human testis including Sertoli cells. In XY individuals, the loss of ATRX leads to ATR-X (alpha thalassemia, mental retardation, X-linked) syndrome associated with a wide range of genital abnormalities such as hypospadias, ambiguous genitalia, and small testes with reduced tubule volume. Our dataset contributes towards understanding the mechanism underlying ATRX regulation of testis development and spermatogenesis.
Project description:The Drosophila spermatogenesis cell differentiation pathway involves the activation of a large set of genes in primary spermatocytes. Most of these genes are activated by testis-specific TATA-binding protein associated factors (tTAFs). In the current model for the activation mechanism, Polycomb plays a key role silencing these genes in the germline precursors, and tTAF-dependent activation in primary spermatocytes involves the displacement of Polycomb from gene promoters. We investigated the genome-wide binding of Polycomb in wild type and tTAF mutant testes. According to the model we expected to see a clear enhancement in Polycomb binding at tTAF-dependent spermatogenesis genes in tTAF mutant testes. However, we find little evidence for such an enhancement in tTAF mutant testes compared to wild type. To avoid problems arising from cellular heterogeneity in whole testis analysis, we further tested the model by analysing Polycomb binding in purified germline precursors, representing cells before tTAF-dependent gene activation. Although we find Polycomb associated with its canonical targets, we find little or no evidence of Polycomb at spermatogenesis genes. The lack of Polycomb at tTAF-dependent spermatogenesis genes in precursor cells argues against a model where Polycomb displacement is the mechanism of spermatogenesis gene activation. This genome-wide ChIP-array study investigates the binding of Polycomb in three biological samples: wild type (WT) whole testes, tTAF (can) mutant whole testes, and FACS-sorted germline precursor cells. We performed two biological replicates for each sample, except wild type whole testes where we performed three. For all ChIP-array experiments, input chromatin was used as the reference control to assay ChIP enrichment. We used Cy3/Cy5-labelled ChIP and input DNA for hybridisation onto Nimblegen arrays, and we performed a Cy3/Cy5 dye swap for one biological replicate of each sample (see supplementary file: GSE39935_README.txt).
Project description:The Drosophila spermatogenesis cell differentiation pathway involves the activation of a large set of genes in primary spermatocytes. Most of these genes are activated by testis-specific TATA-binding protein associated factors (tTAFs). In the current model for the activation mechanism, Polycomb plays a key role silencing these genes in the germline precursors, and tTAF-dependent activation in primary spermatocytes involves the displacement of Polycomb from gene promoters. We investigated the genome-wide binding of Polycomb in wild type and tTAF mutant testes. According to the model we expected to see a clear enhancement in Polycomb binding at tTAF-dependent spermatogenesis genes in tTAF mutant testes. However, we find little evidence for such an enhancement in tTAF mutant testes compared to wild type. To avoid problems arising from cellular heterogeneity in whole testis analysis, we further tested the model by analysing Polycomb binding in purified germline precursors, representing cells before tTAF-dependent gene activation. Although we find Polycomb associated with its canonical targets, we find little or no evidence of Polycomb at spermatogenesis genes. The lack of Polycomb at tTAF-dependent spermatogenesis genes in precursor cells argues against a model where Polycomb displacement is the mechanism of spermatogenesis gene activation.
Project description:Ip6k1 knockout male mice are infertile and display a delay in the first wave of spermatogenesis. To understand the underlying basis of this delay, we compared the gene expression profiles of whole testes from 17 days postpartum (17dpp) and 26 days postpartum (26dpp) Ip6k1 wild type (Ip6k1+/+) and Ip6k1 knockout (Ip6k1-/-) mice. We observed deregulation of several biological processes in Ip6k1-/- testes compared with Ip6k1+/+ testes.
Project description:We investigated somatic cell dynamics in testicular tissue lacking spermatogenesis using model mice with testis-specific deletion of the histone H3 variant gene H3t. Leydig cells in testes lacking spermatogenesis led to increased testosterone synthesis that occurred alongside a high inflammatory response and oxidative stress.
Project description:We investigated somatic cell dynamics in testicular tissue lacking spermatogenesis using model mice with testis-specific deletion of the histone H3 variant gene H3t. Leydig cells in testes lacking spermatogenesis led to increased testosterone synthesis that occurred alongside a high inflammatory response and oxidative stress.