Human Evolution, Department of Organismal Biology, Uppsala University, Uppsala, Sweden.
Department of Biological Sciences, Middle East Technical University, Ankara, Turkey.
Genome Biol Evol. 2024 Jun 4;16(6). doi: 10.1093/gbe/evae114.
Sheep are among the earliest domesticated livestock species, with a wide variety of breeds present today. However, it remains unclear how far back this diversity goes, with formal documentation only dating back a few centuries. North European short-tailed (NEST) breeds are often assumed to be among the oldest domestic sheep populations, even thought to represent relicts of the earliest sheep expansions during the Neolithic period reaching Scandinavia <6,000 years ago. This study sequenced the genomes (up to 11.6X) of five sheep remains from the Baltic islands of Gotland and Åland, dating from the Late Neolithic (∼4,100 cal BP) to historical times (∼1,600 CE). Our findings indicate that these ancient sheep largely possessed the genetic characteristics of modern NEST breeds, suggesting a substantial degree of long-term continuity of this sheep type in the Baltic Sea region. Despite the wide temporal spread, population genetic analyses show high levels of affinity between the ancient genomes and they also exhibit relatively high genetic diversity when compared to modern NEST breeds, implying a loss of diversity in most breeds during the last centuries associated with breed formation and recent bottlenecks. Our results shed light on the development of breeds in Northern Europe specifically as well as the development of genetic diversity in sheep breeds, and their expansion from the domestication center in general.
绵羊是最早被驯化的家畜之一，如今有各种各样的品种。然而，这种多样性可以追溯到多远仍然不清楚，正式的记录只有几百年的历史。北欧短尾（NEST）品种通常被认为是最古老的绵羊群体之一，甚至被认为是新石器时代最早的绵羊扩张到达斯堪的纳维亚的遗迹，距今不到 6000 年。本研究对来自波罗的海的哥特兰岛和奥兰群岛的五只绵羊遗骸进行了基因组测序（高达 11.6X），其年代从晚石器时代（约 4100 年前）到历史时期（约公元 1600 年）。我们的研究结果表明，这些古老的绵羊在很大程度上具有现代 NEST 品种的遗传特征，这表明这种绵羊类型在波罗的海地区存在着相当程度的长期连续性。尽管时间跨度很大，但种群遗传分析表明，古代基因组与现代 NEST 品种之间存在高度的亲和力，并且与现代 NEST 品种相比，它们还表现出相对较高的遗传多样性，这意味着在过去的几个世纪中，大多数品种的多样性都有所丧失，这与品种形成和最近的瓶颈有关。我们的研究结果不仅揭示了北欧品种的发展，还揭示了绵羊品种遗传多样性的发展，以及它们从驯化中心的扩张。
