Centro de Intelixencia Artificial, Ourense, Spain; ESEI, Dept. Informatics, Universidade de Vigo. As Lagoas S/n, Ourense, Spain.
Unidad de Inmunología Hospital Do Meixoeiro, Vigo, Spain.
Dev Comp Immunol. 2021 Jan;114:103868. doi: 10.1016/j.dci.2020.103868. Epub 2020 Sep 17.
Immunoglobulins are essential proteins of the immune system to neutralize pathogens. Gene encoding B cell receptors and antibodies (Ig genes) first appeared with the emergence of early vertebrates having a jaw, and are now present in all extant jawed vertebrates, or Gnathostomata. The genes have undergone evolutionary changes. In particular, genomic structural changes corresponding to genes of the adaptive immune system were coincident or in parallel with the adaptation of vertebrates from the sea to land. In cartilaginous fish exist IgM, IgD/W, and IgNAR and in bony fish IgM, IgT, IgD. Amphibians and reptiles witnessed significant modifications both in the structure and orientation of IG genes. In particular, for these amphibians and Amniota that adapted to land, IgM and IgD genes were retained, but other isotypes arose, including genes for IgA(X)1, IgA(X)2, and IgY. Recent progress in high throughput genome sequencing is helping to uncover the IG gene structure of all jawed vertebrates. In this work, we review the work and present knowledge of immunoglobulin genes in genomes of amphibians and reptiles.
免疫球蛋白是免疫系统中和病原体的必需蛋白。编码 B 细胞受体和抗体的基因（Ig 基因）最早出现在有颚的早期脊椎动物中，现在存在于所有现存的有颚脊椎动物或颌口动物中。这些基因发生了进化变化。特别是，与适应性免疫系统基因相对应的基因组结构变化与脊椎动物从海洋到陆地的适应是一致或并行的。软骨鱼中存在 IgM、IgD/W 和 IgNAR，硬骨鱼中存在 IgM、IgT 和 IgD。两栖动物和爬行动物的 IG 基因在结构和取向方面都发生了显著的改变。特别是对于这些适应陆地的两栖动物和羊膜动物，保留了 IgM 和 IgD 基因，但出现了其他同种型基因，包括 IgA(X)1、IgA(X)2 和 IgY 基因。高通量基因组测序的最新进展有助于揭示所有有颚脊椎动物的 IG 基因结构。在这项工作中，我们回顾了两栖动物和爬行动物基因组中免疫球蛋白基因的研究工作和现有知识。
