Analysis of the reptile CD1 genes: evolutionary implications
Analysis of the reptile CD1 genes: evolutionary implications
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DOI：
10.1007/s00251-015-0837-2
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发表时间：
2015-04
期刊：
影响因子：
3.2
通讯作者：
Zhi Yang;Chunyan Wang;Tao Wang;Jianhui Bai;Yu Zhao;Xuhan Liu;Qingwei Ma;Xiaobing Wu;Ying Guo;Yaofeng Zhao;Liming Ren
中科院分区：
文献类型：
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作者：
Zhi Yang;Chunyan Wang;Tao Wang;Jianhui Bai;Yu Zhao;Xuhan Liu;Qingwei Ma;Xiaobing Wu;Ying Guo;Yaofeng Zhao;Liming Ren
CD1作为第三类抗原提呈分子，以前只在哺乳动物和鸡中发现，这表明鸡和哺乳动物的CD1具有共同的祖先基因，至少出现在3.1亿年前。在这里，我们描述了绿色变态蜥蜴和鳄鱼中的CD1基因，表明CD1在哺乳动物、鸟类和爬行动物中普遍存在。虽然爬行动物的CD1蛋白结构被预测为与人的CD1d和鸡的CD1.1相似，但根据系统发育分析，CD1亚型在哺乳动物、鸟类和爬行动物中并不是同源的，这表明在哺乳动物、鸟类和爬行动物的物种形成过程中，CD1亚型存在独立的多样性。在绿色变态蜥蜴中，虽然单个CD1基因座和MHC I基因位于同一染色体上，但在两者之间有一个大约10Mb长的序列，有趣的是，CD1基因座两侧的几个基因属于人类19号染色体上的MHC近似区。鳄鱼中的CD1基因位于两个基因座上，分别与MHC区和MHC近似区(对应于19号染色体上的MHC近似区)连锁。这些结果为研究CD1的起源和进化提供了新的见解。
CD1, as the third family of antigen-presenting molecules, is previously only found in mammals and chickens, which suggests that the chicken and mammalian CD1 shared a common ancestral gene emerging at least 310 million years ago. Here, we describeCD1genes in the green anole lizard and Crocodylia, demonstrating that CD1 is ubiquitous in mammals, birds, and reptiles. Although the reptilian CD1 protein structures are predicted to be similar to human CD1d and chicken CD1.1, CD1 isotypes are not found to be orthologous between mammals, birds, and reptiles according to phylogenetic analyses, suggesting an independent diversification of CD1 isotypes during the speciation of mammals, birds, and reptiles. In the green anole lizard, although the single CD1 locus and MHC I gene are located on the same chromosome, there is an approximately 10-Mb-long sequence in between, and interestingly, several genes flanking the CD1 locus belong to the MHC paralogous region on human chromosome 19. The CD1 genes in Crocodylia are located in two loci, respectively linked to the MHC region and MHC paralogous region (corresponding to the MHC paralogous region on chromosome 19). These results provide new insights for studying the origin and evolution of CD1.