Project description:We sequenced mRNA in grossly enlarged testes from 1-year-old Stra8-deficient mice, and in testes from adult male wild-type controls, to verify that Stra8-deficient testes are enriched for genes normally expressed in type A spermatogonia. Examination of mRNA levels in 6 whole-testis samples (3 replicates of each genotype). Specifically, we sequenced mRNA in grossly enlarged testes from three 1-year-old Stra8-deficient male mice, and in normal testes from three adult male wild-type controls
Project description:We sequenced mRNA in grossly enlarged testes from 1-year-old Stra8-deficient mice, and in testes from adult male wild-type controls, to verify that Stra8-deficient testes are enriched for genes normally expressed in type A spermatogonia.
Project description:Retinoic acid (RA) induces spermatogonial differentiation, but the mechanism by which it operates remains largely unknown. We developed a germ cell culture assay system to study genes involved in spermatogonial differentiation triggered by RA. Stimulated by Retinoic Acid 8 (Stra8), an RA-inducible gene, is indispensable for meiosis initiation, and its deletion results in a complete block of spermatogenesis at the pre-leptotene/zygotene stage due to failure to complete pre-meiotic DNA replication. To interrogate the role of Stra8 in RA mediated differentiation of spermatogonia, we derived germ cell cultures from the neonatal testis of both wild type and Stra8 knock-out mice. We provide the first evidence that Stra8 plays a crucial role in modulating the responsiveness of undifferentiated spermatogonia to RA and facilitates transition to a differentiated state. Stra8-mediated differentiation is achieved through downregulation of a large portfolio of genes and pathways, most notably including genes involved in the spermatogonial stem cell self-renewal process. We also report here for the first time the role of Transcription Elongation Regulator-1 Like (Tcerg1l) as a downstream effector of RA-induced spermatogonial differentiation.
Project description:To confirm that female-to-male sexual fate reversal in Smad4flox/floxMerCreMer Stra8−/− ovaries occurs independently of somatic environment. We analyzed transcriptome of samples using RNA from control testes, ovaries, Smad4flox/floxMerCreMer Stra8+/− and Smad4flox/floxMerCreMer Stra8−/− ovaries.
Project description:Dmrt1 belongs to the DM domain gene family of conserved sexual regulators. In the mouse Dmrt1 is expressed in the genital ridge (the gonadal primordium) in both sexes and then becomes testis-specific shortly after sex determination. The essential role of DMRT1 in testicular differentiation is well established, and includes transcriptional repression of the meiotic inducer Stra8. However Dmrt1 mutant females are fertile and the role of Dmrt1 in the ovary has not been studied. Here we show in the mouse that most Dmrt1 mutant germ cells in the fetal ovary have greatly reduced expression of STRA8, and fail to properly localize SYCP3 and γH2AX during meiotic prophase. Lack of DMRT1 in the fetal ovary results in the formation of many fewer primordial follicles in the juvenile ovary, although these are sufficient for fertility. Genome-wide chromatin immunoprecipitiation (ChIP-chip) and quantitative ChIP (qChIP) combined with mRNA expression profiling suggests that transcriptional activation of Stra8 in fetal germ cells is the main function of DMRT1 in females, and that this regulation likely is direct. Thus DMRT1 controls Stra8 sex-specifically, activating it in the fetal ovary and repressing it in the adult testis.
