Gipson Terry A
American Institute for Goat Research, Langston University, Langston, OK 73050, USA.
Asian-Australas J Anim Sci. 2019 Aug;32(8):1275-1283. doi: 10.5713/ajas.19.0381. Epub 2019 Jul 18.
Goats (Capra hircus) were domesticated during the late Neolithic, approximately 10,500 years ago, and humans exerted minor selection pressure until fairly recently. Probably the largest genetic change occurring over the millennia happened via natural selection and random genetic drift, the latter causing genes to be fixed in small and isolated populations. Recent human-influenced genetic changes have occurred through biometrics and genomics. For the most part, biometrics has concentrated upon the refining of estimates of heritabilities and genetic correlations. Heritabilities are instrumental in the calculation of estimated breeding values and genetic correlations are necessary in the construction of selection indices that account for changes in multiple traits under selection at one time. Early genomic studies focused upon microsatellite markers, which are short tandem repeats of nucleic acids and which are detected using polymerase chain reaction primers flanking the microsatellite. Microsatellite markers have been very important in parentage verification, which can impact genetic progress. Additionally, microsatellite markers have been a useful tool in assessing genetic diversity between and among breeds, which is important in the conservation of minor breeds. Single nucleotide polymorphisms are a new genomic tool that have refined classical BLUP methodology (biometric) to provide more accurate genomic estimated breeding values, provided a large reference population is available.
山羊（Capra hircus）在新石器时代晚期，即大约10500年前被驯化，直到最近人类才施加了较小的选择压力。在这几千年里发生的可能最大的基因变化是通过自然选择和随机遗传漂变实现的，后者导致基因在小的隔离种群中固定下来。最近受人类影响的基因变化是通过生物统计学和基因组学发生的。在很大程度上，生物统计学专注于改进遗传力和遗传相关性的估计。遗传力在计算估计育种值时很有用，而遗传相关性在构建同时考虑多个被选择性状变化的选择指数时是必要的。早期的基因组研究集中在微卫星标记上，微卫星是核酸的短串联重复序列，通过微卫星两侧的聚合酶链反应引物进行检测。微卫星标记在亲子关系验证中非常重要，这会影响遗传进展。此外，微卫星标记在评估品种间和品种内的遗传多样性方面是一种有用的工具，这在保护小众品种方面很重要。单核苷酸多态性是一种新的基因组工具，它改进了经典的最佳线性无偏预测方法（生物统计学方法），以提供更准确的基因组估计育种值，前提是有大量的参考群体。
