The art of oocyte meiotic arrest regulation.

摘要: A central dogma of mammalian reproductive biology is that the size primordial follicle pool represents capacity in females. The assembly starts after germ cells (PGCs)-derived oocyte releases from synchronously dividing germline cysts. PGCs initiate meiosis during fetal development. However, synapsis and recombination homologous chromosomes, they arrest at diplotene stage first meiotic prophase (MI). diplotene-arrested oocyte, together with surrounding a single layer flattened granulosa cells, forms basic unit ovary, follicle. At start each estrous (animal) or menstrual cycle (human), response to surge luteinizing hormone (LH) pituitary gland, limited number follicles are triggered develop into primary follicles, preantral antral reach preovulatory stage. During transition stages, enclosed gradually acquires resume meiosis. Meiotic resumption MI morphologically characterized by dissolution nuclear envelope, which generally termed “germinal vesicle breakdown” (GVBD). Following GVBD completion MI, enters II without an obvious S-phase arrests metaphase phase (MII) until fertilization. underlying mechanism has been widely explored numerous studies. Many studies indicated two cellular second messengers, cyclic adenosine monophosphate (cAMP) guanosine (cGMP) play essential role maintaining arrest. This review will discuss how these nucleotides regulate maturation blocking initiating processes, provide insight future research.