TY - JOUR TI - Large-scale production of growing oocytes in vitro from neonatal mouse ovaries AU - Honda, Arata AU - Hirose, Michiko AU - Inoue, Kimiko AU - Hiura, Hitoshi AU - Miki, Hiromi AU - Ogonuki, Narumi AU - Sugimoto, Michihiko AU - Abe, Kuniya AU - Kanatsu-Shinohara, Mito AU - Kono, Tomohiro AU - Shinohara, Takashi AU - Ogura, Atsuo T2 - The International Journal of Developmental Biology AB - Although fetal or neonatal mammalian ovaries contain many non-growing oocytes within primordial follicles, most degenerate and only a few contribute to the oocyte pool in the mature ovary. Here, we report a follicle-free culture system that allows a large number of these arrested oocytes to enter the growth phase in vitro. As many as 800 oocytes from a newborn mouse, corresponding to more than 104 oocytes in large animals, continued to develop, formed a zona pellucida, and were able to fuse with spermatozoa. Some oocytes reached the size of those in normal antral follicles and entered metaphase I, indicating the completion of the growth phase. The key to success was the sequential provision of essential nutrients and growth factors to the oocytes, while preventing the apoptosis that normally occurs in the majority of growing oocytes in vivo. Importantly, maternal genomic imprinting, which is necessary for normal embryonic development, was imposed correctly on their genomes autonomously. Thus, arrested primordial oocytes can be rescued effectively in vitro and can undergo the morphological and genomic modifications necessary for fertilization and subsequent embryonic development. This culture system may provide a significant impetus to the development of new techniques for the efficient production of oocytes from fetal or neonatal ovaries, for research, clinical, and zoological purposes. PY - 2009 DO - 10.1387/ijdb.082607ah VL - 53 IS - 4 SP - 605 EP - 613 J2 - Int. J. Dev. Biol. LA - en SN - 0214-6282 SN - 1696-3547 UR - https://ijdb.ehu.eus/article/082607ah Y2 - 2024/05/03/00:09:09 ER -