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In vitro maturation (IVM) is the technique of letting ovarian follicles mature in vitro. ==Techniques available== The ability of in IVM depends on how mature the follicle already is. There are several stages in folliculogenesis, starting with a primordial follicle, which then becomes a primary, secondary, early tertiary (antral), late tertiary and eventually a preovulatory follicle. If a follicle has reached the early tertiary or antral stage, IVM can be carried out. A few live births have already been made〔(NCBI:In vitro maturation of oocytes. Hardy K, Wright CS, Franks S, Winston RM )〕 by taking small early tertiary follicles, letting them mature in vitro and subsequently fertilizing them. However, for follicles that haven't reached the early tertiary stage, IVM is still under development. There are a lot of cellular changes in the oocyte and the rest of the cells in the follicle, which makes it very susceptible. Nevertheless, it is possible to let a primordial follicle mature to a secondary follicle outside the body by growing it in a slice of ovarian tissue.〔 The subsequent maturity from secondary to early tertiary stage can then be supported in test-tubes.〔 It has been suggested that photoirradiation of granulosa cells and oocytes may facilitate IVM.〔Kannan, S., Mehta, A., Simha, V., Reddy, O., Kaur, B., Onteru, S., Singh, D. (2014). (Photoinduction of granulosa cell and oocyte co-culture to influence in vitro maturation and fertilisation ). ''Hypothesis'', 12(1): e7.〕 IVM can be expanded with ''hCG-priming'', which is exposing the ovarian tissue to human chorionic gonadotropin (hCG). This results in an expanding or dispersed pattern of the cumulus oophorus around the egg cell, facilitating its identification within follicular fluid. However, the evidence of a clinical effect of hCG priming is still lacking.〔 IVM can also be expanded with intracytoplasmic sperm injection (ICSI), which should be performed at least one hour (and optimally two to four hours) after the first polar body extrusion.〔 〕 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「In vitro maturation」の詳細全文を読む スポンサード リンク
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