Tokyo University of Agriculture and Technology

Kyushu University

National Agriculture and Food Research Organization

Yayoi Obata

Tomohiro Kono

Katsuhiko Hayashi

Yuji Hirao

Manabu Kawahara

A problem of this invention it to provide a method for differentiate a primordial germ cell into a functional GV stage oocyte by in vitro culture. This invention relates to a method for differentiating a primordial germ cell into a functional GV stage oocyte by in vitro culture, comprising: (a) a step of producing a secondary follicle by culturing the primordial germ cell and supporting cells adjacent to the primordial germ cells under conditions that eliminate the effects of estrogen or a factor having a similar function to estrogen; (b) a step of partially dissociating cells between a granulosa cell layer and a thecal cell layer, wherein an oocyte, the granulosa cell layer, and the thecal cell layer constitute the produced secondary follicle; and (c) a step of differentiating the oocyte into a functional GV stage oocyte by culturing the oocyte, the granulosa cell layer, and the thecal cell layer that constitute the secondary follicle in a medium containing a high-molecular-weight compound.

Culture method for differentiating primordial germ cells into functionally mature oocytes

Disclosed is a method for constructing a nucleus-implanted egg, a parthenogenetic embryo and for producing a parthenogenetic mammal each having 2 haploid genome sets originating in mammalian ova, and provides methods of constructing a nucleus-implanted egg having a haploid genome set derived from primitive ovarian follicle egg (ng ovum) and a haploid genome set from MII phase (second meiosis metaphase) egg (fg ovum), a parthenogenetic embryo and a parthenogenetic mammal, including steps (1) introducing ng ovum into a nucleus-deleted deleted germinal vesicle stage (GV) egg, developing the obtained egg to MII phase by in vitro maturing and culturing to prepare a first nucleus-implanted egg, and (2) extracting MII phase chromosome from the first nucleus-implanted egg and introducing it into other fg ovum to prepare a second nucleus-implanted egg, wherein a ng or fg ovum from which an imprinted gene undergoing epigenetic modification during sperm generation is used.

Method of constructing nucleus-implanted egg, parthenogenetic embryo and parthenogenetic mammal

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Tokyo, Japan

Yayoi Obata