关键词: 东方蜜蜂, 全基因组重测序, 青藏高原, 遗传多样性, 适应性

Abstract: 【Aim】 This study aims to study the population genetic diversity and adaptive evolution of Apis cerana samples from the eastern and southeastern edges of the Qinghai-Tibet Plateau and adjacent areas, so as to provide references for further revealing their genetic resource diversity, population diffusion rules and molecular evolutionary mechanisms of adapting to plateau habitats. 【Methods】 The whole-genomes of 77 colonies of A. cerana samples collected from the eastern and southeastern edges of the Qinghai-Tibet Plateau and adjacent areas were resequenced. The whole-genome reseqeuncing data of the 77 colonies of A. cerana and the reseqeuncing raw data of 90 colonies of A. cerana downloaded from GenBank database were analyzed using population genetic method based on the population structure, principal component analysis, phylogenetic tree, genetic differentiation index, mitochondrial genome haplotype and selective signal analysis. 【Results】 The 167 colonies of A. cerana were separated into four plateau colonies including colonies from Western Sichuan Plateau, Southern Tibet Plateau, Northern Yunnan Plateau and Northern Sichuan Plateau, which clustered into two clades. The average genetic differentiation index of A. cerana colonies in the plateau region (Fst=0.1178) was higher than that in the non-plateau region (Fst=0.0411). The analysis of the minimum genetic distance among populations showed that the colonies of Southern Tibet Plateau, Northern Yunnan Plateau and South Yunnan on the southeastern edge had closer genetic relationships. The colonies of Western Sichuan Plateau and Northern Sichuan Plateau on the eastern edge had closer genetic relationship with those of the Western Sichuan Mountain and Qinba, respectively. Combined with the haplotype analysis of the mitochondrial genome, the ancestral haplotype and origin of the plateau populations on the eastern and southeastern edges of the Qinghai-Tibet Plateau were preliminarily inferred. Through selective analysis, potential selected genes involved in signaling pathways of fatty acid metabolism, phototransduction, temperature adaptation, and ovarian development were identified. Two co-selected genes, ISL-1 and FOXO, were found in the populations of Southern Tibet Plateau and Northern Yunnan Plateau to be mainly involved in insulin secretion in response to cellular stress, suggesting that they play important roles in the adaption of A. cerana to the habitat of the southeastern Qinghai-Tibetan Plateau. 【Conclusion】 The genetic diversity of A. cerana in the Qinghai-Tibet Plateau is highly abundant, and the colonies of Southern Tibet Plateau and Northern Yunnan Plateau on the southeastern edge and Western Sichuan Plateau and Northern Sichuan Plateau on the eastern edge can be obviously distinguished. The four plateau colonies are geographically isolated after the diffusion of non-plateau populations in adjacent areas, resulting in population differentiation. The 
potential genes of plateau environmental adaptability of A. cerana were identified by preliminary screening. This study lays a basis for further exploring the molecular evolutionary mechanism of the adaptation of A. cerana to plateau habitat.

Key words: Apis cerana, whole-genome resequencing, Qinghai-Tibet Plateau, genetic diversity, adaptability