Cai Ronglang, Gu Shuang, Zhang Boxuan, Deng Xuemei, Abdelfattah Mostafa Galal, Yang Ning, Darwish Hesham Y A, Sun Congjiao
Frontier Science Center for Molecular Design Breeding, State Key Laboratory of Animal Biotech Breeding, China Agricultural University, Beijing 100193, China.
National Engineering Laboratory for Animal Breeding and Key Laboratory of Animal Genetics, Breeding and Reproduction, Ministry of Agriculture and Rural Affairs, Department of Animal Genetics and Breeding, College of Animal Science and Technology China Agricultural University, Beijing 100193, China.
Int J Mol Sci. 2025 May 6;26(9):4399. doi: 10.3390/ijms26094399.
Heat-stress resilience is vital for poultry in tropical/subtropical regions where high temperatures impair productivity. Ake chickens, as the only naked-neck chicken breed in China, exhibit robust resistance to heat stress, but this breed lacks clarity in its genetic origins. This study utilized the next-generation sequencing data from 22 chicken breeds to conduct phylogenetic and population analyses. Gene flow analysis revealed a gene migration event from Iranian naked-neck chickens and Indian local breeds to Ake chickens, and population separation estimates suggested that the naked-neck gene was introduced to China around 500-600 years ago. NJ-tree, PCA, and population structure analyses showed that Ake chickens cluster with Yunnan native breeds, which diverged only 100-200 years ago. A selective sweep in the candidate region on chromosome 3 (97.0-97.37 Mb) showed elevated genetic differentiation (F) and reduced nucleotide diversity (π) compared to the genome-wide average, indicating rapid fixation of the trait under natural/artificial selection. Demographic reconstruction indicated that the current effective size of Ake chickens is stable at 2000-3000 individuals. These findings deepen our understanding of Ake chicken evolution and provide valuable insights for conservation and the development of heat-stress-resistant poultry breeds.
热应激恢复力对于热带/亚热带地区的家禽至关重要，在这些地区，高温会影响生产力。阿克鸡是中国唯一的裸颈鸡品种，对热应激表现出强大的抵抗力，但该品种的遗传起源尚不清楚。本研究利用来自22个鸡品种的二代测序数据进行系统发育和群体分析。基因流分析显示存在从伊朗裸颈鸡和印度本地品种到阿克鸡的基因迁移事件，群体分离估计表明裸颈基因大约在500 - 600年前被引入中国。NJ树、主成分分析和群体结构分析表明，阿克鸡与仅在100 - 200年前分化的云南本地品种聚在一起。在3号染色体（97.0 - 97.37 Mb）的候选区域进行的选择性清除分析显示，与全基因组平均水平相比，遗传分化（F）升高，核苷酸多样性（π）降低，表明该性状在自然/人工选择下快速固定。群体动态重建表明，阿克鸡目前的有效群体大小稳定在2000 - 3000只个体。这些发现加深了我们对阿克鸡进化的理解，并为耐热家禽品种的保护和培育提供了有价值的见解。
