BCAS2 regulates oocyte meiosis by participating in alternative mRNA splicing
Oocyte meiosis is an important factor affecting female reproduction. Breast cancer amplified sequence 2 (BCAS2) is a component of the spliceosome. Previous reports have shown that BCAS2 is critical in male germ cell meiosis, oocyte development, and early embryo genome integrity. However, the role of BCAS2 in oocyte meiosis has not been reported. We used Stra8-GFP-Cre mice to knock out BCAS2 during the pachytene phase of oocytes. The results of fertility tests showed that the cko mice were infertile. Morphological analysis showed that the number of primary follicles of 2M ovary was significantly reduced and follicle development was blocked. Further analysis showed that the number of primordial follicles decreased and follicle development slowed from 7dpp ovaries. Sequencing revealed that DNA damage in oocytes could not be repaired from 5dpp. There was an abnormality in meiosis, some oocytes could not reach the diplotene stage of meiosis, and more oocytes could not develop to the dictyate stage. AS analysis reveals that abnormal variable splicing of Dazl and Diaph2 Oogens-related genes in cKO mice, with involvement of the PRP19/CDC5l complex. Overall design: BCAS2 was knocked out in ovarian oocytes, and 1dpp ovaries were taken to analyze and compare the gene expression profiles of RNA-Seq data between WT and knockout groups.