Project description:Prophase I of male meiosis involves dynamic chromosome segregation processes during early spermatogenesis, including synapsis, meiotic recombination, and cohesion. Genetic defects in genes participating in these processes consistently cause reproduction failure in mice. To identify candidate genes responsible for infertility in humans, we performed expression profiling of mouse spermatogenic cells undergoing meiotic prophase I.
Project description:Environmental toxicants have been shown to induce the epigenetic transgenerational inheritance of adult onset disease, including testis disease and male infertility. The exposure of a gestating female during the period of gonadal sex determination has been shown to promote sperm epimutations, differential DNA methylation regions (DMR), that transmit transgenerational disease to subsequent generations. The current study was designed to determine the impact of an altered sperm epigenome on the subsequent development of an adult somatic cell (Sertoli cell) that influences the onset of a specific disease (male infertility). A gestating female rat (F0 generation) was exposed to the agriculture fungicide vinclozolin during gonadal sex determination and then the subsequent F3 generation progeny used for the isolation of Sertoli cells and assessment of testis disease. As previously observed, a spermatogenic cell apoptosis was observed. The Sertoli cells that provide the physical and nutritional support for the spermatogenic cells were isolated and alterations in gene expression examined. Over 400 genes were differentially expressed in the F3 generation control versus vinclozolin lineage Sertoli cells. A number of specific signaling pathways and cellular processes were identified to be transgenerationally altered. One of the key metabolic processes affected was pyruvate/lactate production that is directly linked to spermatogenic cell viability. The Sertoli cell epigenome was also altered with over 100 promoter differential DNA methylation regions (DMR) modified in the vinclozolin F3 generation Sertoli cell. The genomic features and overlap with the sperm DMR were investigated. Observations demonstrate that the transgenerational sperm epigenetic alterations subsequently alters the development of a specific somatic cell (Sertoli cell) epigenome and transcriptome that then has a role in the adult onset disease (male infertility). The environmentally induced epigenetic transgenerational inheritance of testis disease appears to be a component of the molecular etiology of male infertility. Environmental toxicants have been shown to induce the epigenetic transgenerational inheritance of adult onset male infertility. The exposure of a gestating female during the period of gonadal sex determination has been shown to promote sperm epimutations, differential DNA methylation regions (DMR), that transmit transgenerational disease to subsequent generations. The current study was designed to determine the impact of an altered sperm epigenome on the subsequent development of an adult somatic cell (Sertoli cell) that influences the onset of a specific disease (male infertility). A gestating female rat (F0 generation) was exposed to the agriculture fungicide vinclozolin during gonadal sex determination and then the subsequent F3 generation progeny used for the isolation of Sertoli cells and assessment of testis disease. The Sertoli cells provide the physical and nutritional support for the spermatogenic cells in the testis. The F3 generation Sertoli cells have an altered transcriptome and epigenome associated with adult onset testis disease. The environmentally induced epigenetic transgenerational inheritance of Sertoli cell abnormalities appears to be a component of the molecular etiology of male infertility. RNA samples from Sertoli cell of 3 F3-control lineage groups are compared to Sertoli cell of 3 F3-vinclozolin lineage groups
Project description:Hypoxia, an inadequate supply of tissue oxygen tension, has been reported to induce apoptosis of spermatogenic cells and is associated with male infertility. Neddylation, a post-translational modification similar to ubiquitination, has been shown to be involved in the hypoxia stress response. However, the functions of neddylation in hypoxia-induced apoptosis of spermatogenic cells and its association with male infertility remain largely unexplored. In this study, aiming to explore the role of neddylation in male infertility, we used the specific neddylation inhibitor MLN4924 for treatment in mouse type B spermatogonia GC-2 cells. Our results showed that MLN4924 had no apparent effect on GC-2 cell apoptosis under normoxia, but significantly increased apoptotic cells under hypoxia. Transcriptomic analysis and qPCR assay confirmed that MLN4924 could suppress the expression of hypoxia target genes in GC-2 cells under hypoxia. In addition, MLN4924 could enhance the induction of intracellular and mitochondrial reactive oxygen species (ROS) under hypoxia. These results indicate that the neddylation inhibitor MLN4924 potentiates hypoxia-induced apoptosis of mouse type B spermatogonia GC-2 cells, and neddylation may play an important role in promoting spermatogenic cells to adapt to hypoxia stress.