Loss of Estrogen receptor beta disrupts the gene regulation in dormant primordial follicles
Loss of Estrogen receptor beta increases primordial follicle growth activation , which leads to premature depletion of the primordial follicle reserve. We determined the expression and gene regulatory functions of Estrogen receptor beta in dormant PdFs using mice models. PdFs and primary follicles were isolated from 3-week-oldEstrogen receptor beta knockout mouse ovaries and their transcriptomes were compared with that of age-matched control Estrogen receptor beta fl/fl mice. When the PdFs undergo PFGA to form PrFs they activate a large number of new genes, which resulted in a differential expression of ~2,100 genes in Estrogen receptor beta null PrFs. Among the DEGs in Estrogen receptor beta null primary follicles, we also detected downregulation of 1,800 genes and Estrogen receptor beta is the major estrogen receptor in the mammalian ovary that acts as a ligand-activated transcription factor. In this study, we investigated the Estrogen receptor beta regulated genes that play a role in regulating PFGA. We detected the expression of Estrogen receptor beta in the pregranulosa cells and dormant oocytes of the primordial follicle as well as granulosa cells and oocytes of the primary follicles. As expected, there was remarkable upregulation of a large number of genes during PFGA of both Estrogen receptor beta null and control Estrogen receptor beta fl/fl ovaries. However, the upregulation of genes was significantly greater in control Estrogen receptor beta fl/fl ovaries. We in maintaining normal gene expression in primordial follicles.