Cai Ronglang, Yin Zhongtao, Gu Shuang, Deng Xuemei, Darwish Hesham Y A, Sun Congjiao, Yang Ning
State Key Laboratory of Animal Biotech Breeding and Frontier Science Center for Molecular Design Breeding, China Agricultural University, Beijing 100193, China; National Engineering Laboratory for Animal Breeding and Key Laboratory of Animal Genetics, Department of Animal Genetics and Breeding, Breeding and Reproduction, Ministry of Agriculture and Rural Affairs, College of Animal Science and Technology China Agricultural University, Beijing 100193, China.
Department of Applied Biotechnology, Molecular Biology Researches & Studies Institute, Assiut University, Assiut 71526, Egypt.
Poult Sci. 2025 Apr;104(4):104934. doi: 10.1016/j.psj.2025.104934. Epub 2025 Feb 22.
Naked-neck chickens are distributed across tropical and subtropical regions and exhibit notable resistance to heat stress. The naked-neck trait in chickens is an incompletely dominant characteristic determined by the Na gene, and significant differences in feather quantity and distribution have been observed between homozygous and heterozygous individuals. The Ake chicken, a native Chinese breed originating from southwestern Yunnan Province, is the only breed in China that possesses the naked-neck trait. The Ake chicken was developed in a relatively isolated mountain area, and the genetic basis for the determinants of the naked-neck trait in this breed remains unclear. In this study, we utilized Oxford Nanopore Technologies and next-generation sequencing to obtain genomic data from Ake chickens and other naked-neck chicken breeds from Iran and Egypt. Genome sequence alignments revealed that the mutation responsible for the naked-neck trait in Ake chickens was the same as that in naked-neck chickens from other regions, specifically, a 73-kb insertion at the end of chromosome 3. We further demonstrated that the insertion fragment was homologous to the intergenic region between the WNT11 and UVRAG genes at 198 Mb on chromosome 1. The original sequence on chr 1 remained intact without any mutation. This study provides a genetic foundation for the naked-neck trait in chickens and provides a reliable molecular marker for the future breeding of heat stress-resistant chicken breeds.
裸颈鸡分布于热带和亚热带地区，对热应激表现出显著抗性。鸡的裸颈性状是由Na基因决定的不完全显性特征，纯合子和杂合子个体在羽毛数量和分布上存在显著差异。阿克鸡是原产于中国云南省西南部的本土品种，是中国唯一具有裸颈性状的品种。阿克鸡在相对隔离的山区培育而成，该品种裸颈性状决定因素的遗传基础尚不清楚。在本研究中，我们利用牛津纳米孔技术和下一代测序技术，从阿克鸡以及来自伊朗和埃及的其他裸颈鸡品种中获取基因组数据。基因组序列比对显示，阿克鸡中导致裸颈性状的突变与其他地区裸颈鸡的突变相同，具体而言，是3号染色体末端的一个73 kb插入。我们进一步证明，插入片段与1号染色体上198 Mb处WNT11和UVRAG基因之间的基因间区域同源。1号染色体上的原始序列保持完整，没有任何突变。本研究为鸡的裸颈性状提供了遗传基础，并为未来耐热应激鸡品种的育种提供了可靠的分子标记。
