Cartilaginous fishes, comprising the chimeras, sharks, skates, and rays, split from the common ancestor with other jawed vertebrates approx. 450 million years ago. Being the oldest extant taxonomic group to possess an immunoglobulin (Ig)-based adaptive immune system, examination of this group has taught us much about the evolution of adaptive immunity, as well as the conserved and taxon-specific characteristics of Igs. Significant progress has been made analyzing sequences from numerous genomic and transcriptomic data sets. These findings have been supported by additional functional studies characterizing the Igs and humoral response of sharks and their relatives. This review will summarize what we have learned about the genomic organization, protein structure, and in vivo function of these Ig isotypes in cartilaginous fishes and highlight the areas where our knowledge is still lacking.

软骨鱼类，包括嵌合体、鲨鱼、鳐鱼和鳐鱼，从与其他有颌脊椎动物的共同祖先分裂而来的约。4.5亿年前。作为现存最古老的拥有基于免疫球蛋白 (Ig) 的适应性免疫系统的分类群，对该群的检查让我们了解了许多关于适应性免疫的进化，以及 Igs 的保守和分类特异性特征。在分析来自众多基因组和转录组数据集的序列方面取得了重大进展。这些发现得到了其他功能研究的支持，这些研究表征了鲨鱼及其亲属的 Igs 和体液反应。这篇综述将总结我们对基因组组织、蛋白质结构、