ROLE OF GONADOTROPHINS AND MEIOSIS ACTIVATING STEROLS, MAS, IN RESUMPTION OF OOCYTE MEIOSIS

摘要

In mammals and many other vertebrate classes the female germ cell must pass four major check points in order to develop and mature into a fertilizable gamete: 1) initiation of meiosis2) arrest in diplotene stage of meiosis 3) beginning of oocyte growth 4) resumption of meiosis.The first check point, initiation of meiosis in the female germ cells, takes place early in life, often during fetal life. The actual trigger for onset of meiosis is not known. It has been proposed that an "internal clock" may control this process (Tarkowski, 1969). An other possibility is that local paracrine acting substances may be involved, e.g. meiosis activating/preventing substance(s), the balance between which might determine onset or delay of meiosis.