30 Origins, Timing and Introgression of Domestic Geese Revealed by Whole Genome Data

Abstract Geese are one of the most important poultry around the world. For the origin of geese, the current generally accepted hypothesis is that the European domestic geese were originated from the greylag goose (Anser anser), and the Chinese domestic geese have two origins, most breeds of which originated from the swan goose (Anser cygnoides), and the Yili goose originated from the greylag geese. In order to explain the origin and demographic history of geese, we selected 14 goose breeds from Europe and China and wild populations of swan goose and greylag goose, whole genome resequencing data were obtained for 74 samples. Population structure analysis and phylogenetic trees showed that the wild ancestor of the Chinese domestic geese except for Yili was the swan goose, and the wild ancestor of the Chinese Yili geese and European domestic geese was the greylag goose. Analysis of the demographic history suggests that the domestication of the Chinese geese occurred about 3499 years ago and that of the European geese happened about 7552 years ago. Furthermore, there is gene flow found between the domestic geese and their wild ancestors. Analysis of introgression showed that Yili geese had been introgressed by the Chinese domestic geese, and the body size of Yili geese could be influenced by the introgression events of some growth-related genes including IGF-1. Our study provides evidence for the origin of geese at the genome-wide level, and advances the understanding of the history of goose domestication and the traits affected by introgression events.