Bailey Ernest, Petersen Jessica L, Kalbfleisch Theodore S
MH Gluck Equine Research Center, University of Kentucky, Lexington, Kentucky, USA; email:
Department of Animal Science, University of Nebraska, Lincoln, Nebraska, USA; email:
Annu Rev Anim Biosci. 2022 Feb 15;10:131-150. doi: 10.1146/annurev-animal-020420-035235. Epub 2021 Nov 15.
Thoroughbred horses have been selected for racing performance for more than 400 years. Despite continued selection, race times have not improved significantly during the past 60 years, raising the question of whether genetic variation for racing performance still exists. Studies using phenotypes such as race time, money earned, and handicapping, however, demonstrate that there is extensive variation within these traits and that they are heritable. Even so, these are poor measures of racing success since Thoroughbreds race at different ages and distances and on different types of tracks, and some may not race at all. With the advent of genomic tools, DNA variants are being identified that contribute to racing success. Aside from strong associations for myostatin variants with best racing distance, weak to modest associations with racing phenotypes are reported for other genomic regions. These data suggest that diverse genetic strategies have contributed to producing a successful racehorse, and genetic variation contributing to athleticism remains important.
纯种马因比赛成绩而被选育已有400多年历史。尽管持续进行选育，但在过去60年里比赛成绩并未显著提高，这引发了关于比赛成绩的遗传变异是否仍然存在的问题。然而，使用诸如比赛时间、奖金收入和让磅等表型的研究表明，这些性状存在广泛变异且具有遗传性。即便如此，这些都是衡量比赛成功的不佳指标，因为纯种马在不同年龄、不同距离以及不同类型的赛道上比赛，而且有些可能根本不参赛。随着基因组工具的出现，人们正在识别出有助于比赛成功的DNA变异。除了肌生成抑制素变异与最佳比赛距离有强关联外，其他基因组区域与比赛表型的关联较弱至中等。这些数据表明，多种遗传策略有助于培育出成功的赛马，且有助于运动能力的遗传变异仍然很重要。
