Methods used to induce premature oocytes, that are maintained in tissue culture, to progress through developmental stages including to a stage that is competent to undergo FERTILIZATION.

Female germ cells derived from OOGONIA and termed OOCYTES when they enter MEIOSIS. The primary oocytes begin meiosis but are arrested at the diplotene state until OVULATION at PUBERTY to give rise to haploid secondary oocytes or ova (OVUM).

The technique of maintaining or growing mammalian EMBRYOS in vitro. This method offers an opportunity to observe EMBRYONIC DEVELOPMENT; METABOLISM; and susceptibility to TERATOGENS.

The process of germ cell development in the female from the primordial germ cells through OOGONIA to the mature haploid ova (OVUM).

A type of CELL NUCLEUS division, occurring during maturation of the GERM CELLS. Two successive cell nucleus divisions following a single chromosome duplication (S PHASE) result in daughter cells with half the number of CHROMOSOMES as the parent cells.

The granulosa cells of the cumulus oophorus which surround the OVUM in the GRAAFIAN FOLLICLE. At OVULATION they are extruded with OVUM.