SRSF1 is involved in alternative mRNA splicing in granulosa cell survival

Granulosa cells abnormalities are one of the characteristics of premature ovarian insufficiency (POI). Abnormal expression of serine/arginine-rich splicing factor 1 (SRSF1) can causes a variety of diseases, but the role of SRSF1 in mouse granulosa cells has been poorly reported. In this study, we found that SRSF1 was expressed in the nuclei of both mouse oocytes and granulosa cells. Specific knockout of SRSF1 in granulosa cells was performed using Foxl2-creERT2 mice, and morphological staining showed that follicular development was blocked. In addition, granulosa cell proliferation decreased and cell apoptosis increased. The differential gene Gene Ontology (GO) analysis of RNA-Seq results showed abnormal expression of DNA repair, cell killing and other signaling pathways. Alternative splicing (AS) analysis showed that SRSF1 affected DNA damage in granulosa cells by regulating genes related to DNA repair. In conclusion, SRSF1 in granulosa cells affects female reproduction by controlling the development of follicles through regulating granulosa cell DNA repair related genes. SRSF1 was knocked out in ovarian granulosa cells, and 9dpp ovaries were taken to analyze and compare the gene expression profiles of RNA-Seq data between WT and knockout groups.

颗粒细胞异常是早发性卵巢功能不全（premature ovarian insufficiency, POI）的特征之一。富含丝氨酸/精氨酸剪接因子1（serine/arginine-rich splicing factor 1, SRSF1）的表达异常可引发多种疾病，但目前关于SRSF1在小鼠颗粒细胞中的作用却鲜有报道。本研究中，我们发现SRSF1在小鼠卵母细胞与颗粒细胞的细胞核中均有表达。采用Foxl2-creERT2小鼠对颗粒细胞中的SRSF1进行特异性敲除，形态学染色结果显示卵泡发育受阻。此外，颗粒细胞的增殖能力下降，细胞凋亡水平升高。对RNA测序（RNA-Seq）结果进行差异基因基因本体（GO）分析后发现，DNA损伤修复、细胞杀伤等信号通路存在异常表达。可变剪接（alternative splicing, AS）分析结果显示，SRSF1可通过调控DNA损伤修复相关基因，影响颗粒细胞的DNA损伤。综上，颗粒细胞中的SRSF1可通过调控颗粒细胞的DNA损伤修复相关基因，影响卵泡发育，进而对雌性生殖功能产生调控作用。本研究对卵巢颗粒细胞中的SRSF1进行敲除，并提取出生后第9天（9dpp）的卵巢组织，对野生型（wild type, WT）与敲除组的RNA测序数据的基因表达谱进行分析与比较。