The Roslin Institute, University of Edinburgh, Easter Bush Campus, Easter Bush, Midlothian, EH25 9RG, United Kingdom.
Dairy Research Centre, Scotland's Rural College (SRUC), Barony Campus, Dumfries, DG1 3NE, United Kingdom.
BMC Genom Data. 2024 Sep 17;25(1):82. doi: 10.1186/s12863-024-01265-3.
Sheep breeds native to the United Kingdom exhibit a striking diversity of different traits. Some of these traits are highly sustainable, such as seasonal wool shedding in the Wiltshire Horn, and are likely to become more important as pressures on sheep production increase in coming decades. Despite their clear importance to the future of sheep farming, the genetic diversity of native UK sheep breeds is poorly characterised. This increases the risk of losing the ability to select for breed-specific traits from native breeds that might be important to the UK sheep sector in the future. Here, we use 50 K genotyping to perform preliminary analysis of breed relationships and genetic diversity within native UK sheep breeds, as a first step towards a comprehensive characterisation. This study generates novel data for thirteen native UK breeds, including six on the UK Breeds at Risk (BAR) list, and utilises existing data from the publicly available Sheep HapMap dataset to investigate population structure, heterozygosity and admixture.
In this study the commercial breeds exhibited high levels of admixture, weaker population structure and had higher heterozygosity compared to the other native breeds, which generally tend to be more distinct, less admixed, and have lower genetic diversity and higher kinship coefficients. Some breeds including the Wiltshire Horn, Lincoln Longwool and Ryeland showed very little admixture at all, indicating a high level of breed integrity but potentially low genetic diversity. Population structure and admixture were strongly influenced by sample size and sample provenance - highlighting the need for equal sample sizes, sufficient numbers of individuals per breed, and sampling across multiple flocks. The genetic profiles both within and between breeds were highly complex for UK sheep, reflecting the complexity in the demographic history of these breeds.
Our results highlight the utility of genotyping data for investigating breed diversity and genetic structure. They also suggest that routine generation of genotyping data would be very useful in informing conservation strategies for rare and declining breeds with small population sizes. We conclude that generating genetic resources for the sheep breeds that are native to the UK will help preserve the considerable genetic diversity represented by these breeds, and safe-guard this diversity as a valuable resource for the UK sheep sector to utilise in the face of future challenges.
原产于英国的绵羊品种表现出显著的不同特征多样性。其中一些特征具有很强的可持续性，例如威尔特郡角羊的季节性羊毛脱落，随着未来几十年绵羊生产压力的增加，这些特征可能变得更加重要。尽管它们对未来绵羊养殖的重要性显而易见，但英国本土绵羊品种的遗传多样性却描述不足。这增加了从未来对英国绵羊部门可能重要的本土品种中选择特定品种特征的能力丧失的风险。在这里，我们使用 50K 基因分型来初步分析原产于英国的绵羊品种之间的品种关系和遗传多样性，作为全面特征描述的第一步。本研究为十三个原产于英国的品种生成了新的数据，包括六个在英国濒危品种（BAR）名单上的品种，并利用 Sheep HapMap 数据集的现有数据来研究种群结构、杂合度和杂种。
在本研究中，商业品种表现出高水平的杂种，较弱的种群结构和较高的杂合度，与其他本土品种相比，这些品种通常更具特色，杂种较少，遗传多样性和亲缘系数较低。一些品种，包括威尔特郡角羊、林肯长羊毛和莱兰羊，几乎没有杂交，表明品种完整性很高，但潜在的遗传多样性很低。种群结构和杂种受样本大小和样本来源的强烈影响-突出了需要具有相同的样本大小、每个品种足够数量的个体以及跨多个羊群进行采样。英国绵羊的品种内和品种间的遗传特征非常复杂，反映了这些品种的人口历史的复杂性。
我们的结果突出了基因分型数据在研究品种多样性和遗传结构方面的效用。它们还表明，常规生成基因分型数据对于为具有小种群规模的稀有和衰退品种制定保护策略非常有用。我们的结论是，为原产于英国的绵羊品种生成遗传资源将有助于保护这些品种所代表的大量遗传多样性，并将这种多样性作为英国绵羊部门在未来面临挑战时利用的宝贵资源加以保护。
