Ishii Toshimichi, Tomita Kensuke, Sakakibara Hideo, Ohkura Satoshi
Department of Livestock Improvement and Reproduction, Mie Prefectural Livestock Research Center, Mie 515-2324, Japan.
Laboratory of Animal Production Science, Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya 464-8601, Japan.
J Reprod Dev. 2018 Feb 27;64(1):95-99. doi: 10.1262/jrd.2017-095. Epub 2017 Oct 20.
This study was aimed at evaluating the effects of multi-layered cumulus cells (MCCs) during vitrification and in vitro fertilization (IVF) of mature bovine oocytes and embryogenesis after IVF. The rates of cleavage and blastocyst formation were higher in vitrified and fertilized oocytes with MCCs than in denuded oocytes (P < 0.05), but were comparable to the rates in fresh oocytes with MCCs or without (denuded). When the MCC-enclosed oocytes were denuded before IVF, blastocyst formation rate reduced compared with that in vitrified oocytes with MCCs (P < 0.05). This suggested that the MCCs surrounding the mature bovine oocytes play important roles during cryopreservation: protecting them against freezing and promoting their survival and development post IVF, thereby increasing the success rates of IVF and embryonic development. Herein, we showed for the first time that calves could be produced using only 14-19 vitrified mature oocytes with MCCs from the ovaries of individual cows post slaughter.
本研究旨在评估多层卵丘细胞（MCCs）在成熟牛卵母细胞玻璃化冷冻及体外受精（IVF）过程中的作用以及IVF后的胚胎发育情况。与裸卵相比，带有MCCs的玻璃化冷冻及受精卵母细胞的卵裂率和囊胚形成率更高（P < 0.05），但与带有或不带有（裸卵）MCCs的新鲜卵母细胞的比率相当。当在IVF前去除包裹有MCCs的卵母细胞的卵丘细胞时，囊胚形成率与带有MCCs的玻璃化冷冻卵母细胞相比降低（P < 0.05）。这表明围绕成熟牛卵母细胞的MCCs在冷冻保存过程中发挥重要作用：保护它们免受冷冻影响，并促进其在IVF后的存活和发育，从而提高IVF和胚胎发育的成功率。在此，我们首次表明，仅使用屠宰后个体母牛卵巢中14 - 19个带有MCCs的玻璃化冷冻成熟卵母细胞就能培育出小牛。
