Takasu Masaki, Hiramatsu Nana, Tozaki Teruaki, Kakoi Hironaga, Nakagawa Takeru, Hasegawa Telhisa, Maeda Masami, Murase Tetsuma, Mukoyama Harutaka
Department of Veterinary Medicine, Faculty of Applied Biological Sciences, Gifu University, 1–1 Yanagido, Gifu 501–1193, Japan.
J Vet Med Sci. 2012 Feb;74(2):161-6. doi: 10.1292/jvms.11-0025. Epub 2011 Sep 30.
In order to contribute to conservation of the endangered Kiso horse, we clarified their genetic information using 31 microsatellite DNAs, and genotyped 125 horses, 83% of the existing breed. First, we clarified the current status of the horses. The horses were confirmed to have experienced rapid loss of population causing a bottleneck, and their effective population size was much smaller than their census size. Moreover, the number of alleles (6.3), observed heterozygosity (0.674), and expected heterozygosity (0.662) were in the same range as other endangered horses all over the world. Therefore, although their inbreeding level was not so severe (F(is): -0.017), the Kiso horse is surely one of the endangered. Second, we obtained genetic information of individuals. This information allowed us to understand the genetic distance of individuals, and might help in development of a reproductive strategy concerning the genetic distance between the mating pairs. Moreover, there appeared to be 4 subpopulations of Kiso horse, and this result was in good agreement with their historical background. Third, we confirmed that the parentage test for identification using the 31 microsatellite DNAs was highly reliable (probability of exclusion: 0.999999993). This identification increases the reliability of stud certification, and is also helpful for effective management. Understanding the genetic diversity within the population and the relationships among individuals is important to ensuring effective management for maintenance of genetic variation, and this study may help in conservation of the endangered Kiso horse.
为了促进对濒危木曾马的保护，我们使用31个微卫星DNA对其遗传信息进行了阐明，并对125匹马（占现有品种的83%）进行了基因分型。首先，我们明确了这些马的现状。已证实这些马经历了导致瓶颈效应的种群快速减少，其有效种群规模远小于普查规模。此外，等位基因数量（6.3）、观察到的杂合度（0.674）和预期杂合度（0.662）与世界各地其他濒危马处于相同范围。因此，尽管它们的近亲繁殖水平并不十分严重（F(is)：-0.017），但木曾马无疑是濒危物种之一。其次，我们获得了个体的遗传信息。这些信息使我们能够了解个体间的遗传距离，并可能有助于制定关于交配对象间遗传距离的繁殖策略。此外，木曾马似乎存在4个亚种群，这一结果与其历史背景高度吻合。第三，我们证实使用31个微卫星DNA进行身份鉴定的亲权测试具有高度可靠性（排除概率：0.999999993）。这种鉴定提高了种马认证的可靠性，也有助于有效管理。了解种群内的遗传多样性以及个体间的关系对于确保维持遗传变异的有效管理很重要，本研究可能有助于濒危木曾马的保护。
