Wang, D.-F. | bioRxiv Science

bioRxiv2023

Genomic analyses of Asiatic Mouflon in Iran provide insights into the domestication and evolution of sheep

BackgroundAsiatic mouflon (O. gmelini) consists of several subspecies mainly distributed in Armenia, southern Azerbaijan, Cyprus, northern, southern, and western regions of Iran, and eastern and central regions of Turkey nowadays. Genome analyses of Asiatic mouflon in Iran revealed that they could have diverged from the direct ancestor of domestic sheep, and showed genetic introgression into domestic sheep after domestication. However, the impact of the Asiatic mouflon subspecies in Iran on sheep domestication remains unclear. ResultsHere, we conducted a comprehensive population genomics analysis of Asiatic mouflons in Iran with 780 whole-genome sequences, 767 whole mitogenomes, and 239 Y chromosomes. Whole-genome sequence analyses revealed two subpopulations of the Asiatic mouflons in Iran: O. gmelini_2 limited in Kabudan and O. gmelini_1 over a wide geographic area. Phylogenetic analyses of the Asiatic mouflons in Iran based on uniparental variants revealed a monophyletic lineage with the mitochondrial haplogroups C+E, and clustered into a monophyletic with Y-chromosomal lineage HY2 of sheep. Additionally, introgression tests detected significant signals of genetic introgression from O. gmelini_2 to four sheep populations (e.g., Garut, Garole, Bangladeshi, and Sumatra) in South and Southeast Asia. In the four sheep populations, selective tests and introgression signals revealed that the wild introgression could have contributed to their small body size and local adaptation to the hot and humid environments in the Indian Peninsula. ConclusionsOur results suggested that the maternal haplogroups C+E and paternal lineage HY2 could have originated from the Asiatic mouflon in Iran. Also, our findings provide new insights into sheep domestication and subsequent introgressions from wild ancestors to domestic populations.

evolutionary biology↗

bioRxiv2021

Whole-genome sequence analysis unveils different origins of European and Asiatic mouflon and domestication-related genes in sheep

The domestication and subsequent development of sheep are crucial events in the history of human civilization and the agricultural revolution. However, the impact of interspecific introgression on the genomic regions under domestication and subsequent selection remains unclear. Here, we analyze the whole genomes of domestic sheep and all their wild relative species. We found introgression from wild sheep such as the snow sheep and its American relatives (bighorn and thinhorn sheep) into urial, Asiatic and European mouflons. We observed independent events of adaptive introgression from wild sheep into the Asiatic and European mouflons, as well as shared introgressed regions from both snow sheep and argali into Asiatic mouflon before or during the domestication process. We revealed European mouflons arose through hybridization events between a now extinct sheep in Europe and feral domesticated sheep around 6,000 - 5,000 years BP. We also unveiled later introgressions from wild sheep to their sympatric domestic sheep after domestication. Several of the introgression events contain loci with candidate domestication genes (e.g., PAPPA2, NR6A1, SH3GL3, RFX3 and CAMK4), associated with morphological, immune, reproduction or production traits (wool/meat/milk). We also detected introgression events that introduced genes related to nervous response (NEURL1), neurogenesis (PRUNE2), hearing ability (USH2A) and placental viability (PAG11 and PAG3) to domestic sheep and their ancestral wild species from other wild species.

evolutionary biology↗