Yi Xiaohua, Liu Xiangyu, Sun Xiuzhu, Wang Shuhui
College of Animal Science and Technology, Northwest A&F University, Yangling 712100, China.
College of Grassland Agriculture, Northwest A&F University, Yangling 712100, China.
Vet J. 2025 Feb;309:106295. doi: 10.1016/j.tvjl.2024.106295. Epub 2024 Dec 22.
Immunoglobulins are important components of humoral immunity and play a crucial role in protecting the body from external antigens. The Arctic fox is an important member of furbearer farming, but due to the lack of research on the immune system of the Arctic fox, animal welfare regarding Arctic fox farming has still not received enough attention. In this study, we used the Arctic fox as a research subject, described the gene locus structure of the Arctic fox immunoglobulin germline by genome comparison, and analysed the mechanism of expression diversity of the antibody pool of the Arctic fox by rapid amplification of cDNA 5' ends and high-throughput sequencing. The results showed that the Arctic fox IgH, Igκ and Igλ loci were located on chromosome 6, chromosome 5 and chromosome 14, respectively. The number of variable (V) genes identified were 18, 11 and 10, and the number of joining (J) were 3, 4 and 13 and six diversity (D) genes in the heavy chain, respectively. Among them, the D genes, J genes and constant region genes of the heavy chain were arranged in the middle of the two variable heavy gene clusters; Arctic fox had a strong preference for the use of V genes, D genes and J genes, which resulted in a low level of V(D)J recombination diversity; linkage diversity analyses showed that random deletion of the V and J genes and insertion of the N and P nucleotides of the immunoglobulins of the Arctic foxes had a large impact on the linkage diversity of the IgH, whereas the light chain The linkage diversity was mainly contributed by the random deletion of V and J genes, and the insertion of N and P nucleotides had a smaller effect; somatic hypermutation (SHM) analysis showed that the mutation types of SHM of the heavy and light chains of the Arctic fox had a strong bias towards G>A and A>G, and the bias exhibited by the three chains was basically the same. By analysing the structure and expression diversity analysis of the Arctic fox gene loci, this study could provide a theoretical basis for antibody design and vaccine development in the Arctic fox, and provide new insights to further improve the animal welfare level of Arctic fox farming.
免疫球蛋白是体液免疫的重要组成部分，在保护机体免受外来抗原侵害方面发挥着关键作用。北极狐是毛皮动物养殖的重要成员，但由于对北极狐免疫系统缺乏研究，北极狐养殖中的动物福利仍未得到足够重视。在本研究中，我们以北极狐为研究对象，通过基因组比较描述了北极狐免疫球蛋白种系的基因座结构，并通过cDNA 5'末端快速扩增和高通量测序分析了北极狐抗体库表达多样性的机制。结果表明，北极狐的IgH、Igκ和Igλ基因座分别位于6号染色体、5号染色体和14号染色体上。鉴定出的可变（V）基因数量分别为18个、11个和10个，连接（J）基因数量分别为3个、4个和13个，重链中有6个多样性（D）基因。其中，重链的D基因、J基因和恒定区基因排列在两个可变重基因簇中间；北极狐对V基因、D基因和J基因的使用有较强偏好，导致V（D）J重组多样性水平较低；连锁多样性分析表明，北极狐免疫球蛋白V和J基因的随机缺失以及N和P核苷酸的插入对IgH的连锁多样性有较大影响，而轻链的连锁多样性主要由V和J基因的随机缺失贡献，N和P核苷酸的插入影响较小；体细胞高频突变（SHM）分析表明，北极狐重链和轻链SHM的突变类型对G>A和A>G有强烈偏向，三条链表现出的偏向基本相同。通过对北极狐基因座结构和表达多样性分析，本研究可为北极狐抗体设计和疫苗开发提供理论依据，并为进一步提高北极狐养殖动物福利水平提供新的见解。
