Class I genes have split from the MHC in the tammar wallaby
Class I genes have split from the MHC in the tammar wallaby
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DOI：
10.1159/000098188
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发表时间：
2007-01-01
影响因子：
1.7
通讯作者：
Graves, J. A. M.
中科院分区：
文献类型：
--
作者：
Deakin, J. E.;Siddle, H. V.;Graves, J. A. M.
主要组织相容性复合体（MHC）中的基因对免疫应答和免疫调节至关重要。比较研究表明，MHC在整个进化过程中经历了许多变化，但在四足动物中，三种不同类别的MHC基因保持连锁，这表明通过保持MHC基因的这种聚类可能获得一些功能优势。在这里，我们目前的数据显示，第二类和第三类基因，抗原加工基因TAP 2，和MHC框架基因被发现在一起的tammar小袋鼠2号染色体上。令人惊讶的是，在2号染色体上没有发现I类基因座，而是将其映射到分布在6条染色体上的10个不同位置。I类基因座在小袋鼠几乎所有常染色体上的这种分布并不是所有有袋动物的特征，可能是一个相对较新的现象。它强调了在比较研究中纳入不止一种有袋动物物种的必要性，并提出了有关MHC基因聚集的功能意义的问题。版权所有（c）2007 S. Karger AG，巴塞尔
Genes within the Major Histocompatibility Complex (MHC) are critical to the immune response and immunoregulation. Comparative studies have revealed that the MHC has undergone many changes throughout evolution yet in tetrapods the three different classes of MHC genes have maintained linkage, suggesting that there may be some functional advantage obtained by maintaining this clustering of MHC genes. Here we present data showing that class II and III genes, the antigen processing gene TAP2, and MHC framework genes are found together in the tammar wallaby on chromosome 2. Surprisingly class I loci were not found on chromosome 2 but were mapped to ten different locations spread across six chromosomes. This distribution of class I loci in the wallaby on nearly all autosomes is not a characteristic of all marsupials and may be a relatively recent phenomenon. It highlights the need for the inclusion of more than one marsupial species in comparative studies and raises questions regarding the functional significance of the clustering of MHC genes. Copyright (c) 2007 S. Karger AG, Basel