Hashiyada Yutaka
National Livestock Breeding Center, Fukushima 961-8511, Japan.
J Reprod Dev. 2017 Dec 15;63(6):527-538. doi: 10.1262/jrd.2017-096. Epub 2017 Oct 15.
Production of sires with high breeding potential is indispensable for prompt and reliable breeding using their semen in the cattle industry. Currently, in Japan, we aim to further the production of Japanese black sires via a new breeding system that uses genetically homologous monozygotic twins so that better growth performance and carcass traits can be translated to the increased production of beef with higher economic value. Several studies have reported that monozygotic twins are produced by embryo bisection. On the other hand, with the evolution and stabilization of in vitro fertilization technology, it has become possible to produce multiple monozygotic twin calves from blastomeres separated from a cleavage-stage embryo. This review attempts to clarify breeding practices through revalidation of the factors that affect the production efficiency of monozygotic twin calves by embryo bisection. Furthermore, the establishment of a system for monozygotic twin embryo production via the simplified technique of blastomere separation is reviewed while showing data from our previously performed studies.
培育具有高繁殖潜力的种公牛对于在养牛业中迅速且可靠地利用其精液进行繁殖而言不可或缺。目前在日本，我们旨在通过一种使用基因同源单卵双胞胎的新繁殖系统来进一步培育日本黑牛种公牛，以便将更好的生长性能和胴体性状转化为更高经济价值牛肉产量的增加。多项研究报告称，单卵双胞胎是通过胚胎分割产生的。另一方面，随着体外受精技术的发展和稳定，已能够从卵裂期胚胎分离出的卵裂球中生产出多头单卵双胞胎犊牛。本综述试图通过重新验证影响胚胎分割产生单卵双胞胎犊牛生产效率的因素来阐明繁殖实践。此外，在展示我们之前所进行研究的数据的同时，对通过简化的卵裂球分离技术建立单卵双胞胎胚胎生产系统进行了综述。
