Institute for Genetics, University of Cologne, Cologne, Germany.
WA Franke College of Forestry and Conservation, University of Montana, Missoula, United States.
Elife. 2024 Jun 4;13:e98058. doi: 10.7554/eLife.98058.
Copy number variation in large gene families is well characterized for plant resistance genes, but similar studies are rare in animals. The zebrafish () has hundreds of NLR immune genes, making this species ideal for studying this phenomenon. By sequencing 93 zebrafish from multiple wild and laboratory populations, we identified a total of 1513 NLRs, many more than the previously known 400. Approximately half of those are present in all wild populations, but only 4% were found in 80% or more of the individual fish. Wild fish have up to two times as many NLRs per individual and up to four times as many NLRs per population than laboratory strains. In contrast to the massive variability of gene copies, nucleotide diversity in zebrafish NLR genes is very low: around half of the copies are monomorphic and the remaining ones have very few polymorphisms, likely a signature of purifying selection.
在植物抗性基因中，对大片段基因家族的拷贝数变异进行了很好的研究，但在动物中类似的研究很少。斑马鱼（）拥有数百个 NLR 免疫基因，使其成为研究这一现象的理想物种。通过对来自多个野生和实验室种群的 93 条斑马鱼进行测序，我们总共鉴定出 1513 个 NLR，远远超过之前已知的 400 个。大约一半的 NLR 存在于所有野生种群中，但只有 4%的 NLR 在 80%或更多的个体中被发现。野生鱼类的每个个体的 NLR 数量是实验室种群的两倍，每个种群的 NLR 数量是实验室种群的四倍。与基因拷贝的巨大变异性形成鲜明对比的是，斑马鱼 NLR 基因的核苷酸多样性非常低：大约一半的拷贝是单态的，其余的拷贝只有很少的多态性，这可能是纯化选择的特征。
