Transcriptome Analysis of Key Genes Involved in the Initiation of Spermatogonial Stem Cell Differentiation.

PURPOSE: The purpose of this study was to screen the genes and pathways that are involved in spermatogonia stem cell (SSC) differentiation regulation during the transition from Aundiff to A1. Methods: RNA sequencing was performed to screen differentially expressed genes at 1 d and 2 d after SSC differentiation culture. KEGG pathway enrichment and GO function analysis were performed to reveal the genes and pathways related to the initiation of early SSC differentiation. RESULTS: The GO analysis showed that Rpl21, which regulates cell differentiation initiation, significantly increased after 1 day of SSC differentiation. The expressions of Fn1, Cd9, Fgf2, Itgb1, Epha2, Ctgf, Cttn, Timp2 and Fgfr1, which are related to promoting differentiation, were up-regulated after 2 days of SSC differentiation. The analysis of the KEGG pathway revealed that RNA transport is the most enriched pathway 1 day after SSC differentiation. Hspa2, which promotes the differentiation of male reproductive cells, and Cdkn2a, which participates in the cell cycle, were significantly up-regulated. The p53 pathway and MAPK pathway were the most enriched pathways 2 days after SSC differentiation. Cdkn1a, Hmga2, Thbs1 and Cdkn2a, microRNAs that promote cell differentiation, were also significantly up-regulated. CONCLUSIONS: RNA transport, the MAPK pathway and the p53 pathway may play vital roles in early SSC differentiation, and Rpl21, Fn1, Cd9, Fgf2, Itgb1, Epha2, Ctgf, Cttn, Timp2, Fgfr1, Hspa2, Cdkn2a, Cdkn1a, Hmga2 and Thbs1 are involved in the initiation of SSC differentiation. The findings of this study provide a reference for further revelations of the regulatory mechanism of SSC differentiation.

Transcriptome Analysis in High Temperature Inhibiting Spermatogonial Stem Cell Differentiation In Vitro.

As one of the factors of male infertility, high temperature induces apoptosis of differentiated spermatogenic cells, sperm DNA oxidative damage, and changes in morphology and function of Sertoli cells. Spermatogonial stem cells (SSCs) are a type of germline stem cells that maintain spermatogenesis through self-renewal and differentiation. At present, however, the effect of high temperature on SSC differentiation remains unknown. In this study, an in vitro SSC differentiation model was used to investigate the effect of heat stress treatment on SSC differentiation, and RNA sequencing (RNA-seq) was used to enrich the key genes and pathways in high temperature inhibiting SSC differentiation. Results show that 2 days of 37 °C or 43 °C (30 min per day) heat stress treatment significantly inhibited SSC differentiation. The differentiation-related genes c-kit, stra8, Rec8, Sycp3, and Ovol1 were down-regulated after 2 and 4 days of heat stress at 37 °C. The transcriptome of SSCs was significantly differentially expressed on days 2 and 4 after heat stress treatment at 37 °C. In total, 1660 and 7252 differentially expressed genes (DEGs) were identified by RNA-seq in SSCs treated with heat stress at 37 °C for 2 and 4 days, respectively. KEGG pathway analysis showed that p53, ribosome, and carbon metabolism signaling pathways promoting stem cell differentiation were significantly enriched after heat stress treatment at 37 °C. In conclusion, 37 °C significantly inhibited SSC differentiation, and p53, ribosome, and carbon metabolism signaling pathways were involved in this differentiation inhibition process. The results of this study provide a reference for further investigation into the mechanism by which high temperature inhibits SSC differentiation.