Dear Editor,
Primary ovarian insufficiency (POI) is defined as a significant reduction of the follicle pool and induction of amenorrhea before the age of 40 (Nelson, 2009), associated with a decreased level of estrogen and hypergonadotropic state in the blood. Since POI patients have few follicles, it is difficult to obtain human oocytes to decipher this disease. In mammalian ovary, granulosa cells establish direct communication with oocytes and modulate transcription and chromatin remodeling of the oocyte (De La Fuente and Eppig, 2001). However, the whole-genomic DNA methylation profile of human granulosa cells and the potential clinical insights are absent.
