Department of Ecology and Evolutionary Biology, University of California Santa Cruz, Santa Cruz, CA, USA.
Howard Hughes Medical Institute, University of California Santa Cruz, Santa Cruz, CA, USA.
Science. 2023 Apr 28;380(6643):eabn5887. doi: 10.1126/science.abn5887.
We reconstruct the phenotype of Balto, the heroic sled dog renowned for transporting diphtheria antitoxin to Nome, Alaska, in 1925, using evolutionary constraint estimates from the Zoonomia alignment of 240 mammals and 682 genomes from dogs and wolves of the 21st century. Balto shares just part of his diverse ancestry with the eponymous Siberian husky breed. Balto's genotype predicts a combination of coat features atypical for modern sled dog breeds, and a slightly smaller stature. He had enhanced starch digestion compared with Greenland sled dogs and a compendium of derived homozygous coding variants at constrained positions in genes connected to bone and skin development. We propose that Balto's population of origin, which was less inbred and genetically healthier than that of modern breeds, was adapted to the extreme environment of 1920s Alaska.
我们使用 240 种哺乳动物的 Zoonomia 比对和 21 世纪的犬科动物和狼的 682 个基因组的进化约束估计值，重建了 1925 年因运送白喉抗毒素而闻名的英雄雪橇犬巴尔托的表型。巴尔托与同名的西伯利亚哈士奇犬只有部分的多样化祖先。巴尔托的基因型预测了一种与现代雪橇犬品种不同的毛色特征组合，而且体型稍小。与格陵兰雪橇犬相比，它的淀粉消化能力更强，并且在与骨骼和皮肤发育相关的基因中，受约束位置的纯合编码变异也更多。我们提出，巴尔托的起源种群的近交程度和遗传健康状况都低于现代品种，这使其适应了 20 世纪 20 年代阿拉斯加的极端环境。
