Natural selection and the evolutionary history of major histocompatibility complex loci.
Natural selection and the evolutionary history of major histocompatibility complex loci.
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DOI：
10.2741/a298
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发表时间：
1998-05
期刊：
影响因子：
--
通讯作者：
A. Hughes;M. Yeager
中科院分区：
文献类型：
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作者：
A. Hughes;M. Yeager
主要组织相容性复合体（MHC）是脊椎动物特有的多基因家族，其产物的功能是将肽提呈给T细胞。某些MHC基因座是高度多态性的，这种多态性是通过一种平衡选择的形式来维持的，可能是超显性选择。这种选择对MHC生物学有几个后果，使这些基因不同于中性进化的基因：编码肽结合区的密码子中的非同义核苷酸取代率提高;持久（“跨物种”）多态性;以及由于重组和随后的遗传漂变而导致的内含子相对于外显子的同质化。MHC还揭示了与其他多基因家族共享的过程的证据，包括基因复制和缺失以及低水平的基因座间重组。
The major histocompatibility complex (MHC) is a multi-gene family unique to the vertebrates, whose products function to present peptides to T cells. Certain MHC loci are highly polymorphic, and this polymorphism is maintained by a form of balancing selection, probably overdominant selection. This selection has several consequences for MHC biology that make these genes different from neutrally evolving genes: an enhanced rate of nonsynonymous nucleotide substitution in codons encoding the peptide-binding region; long-lasting ("trans-species") polymorphism; and homogenization of introns relative to exons as a result of recombination and subsequent genetic drift. The MHC also reveals evidence of processes shared with other multi-gene families, including gene duplication and deletion and a low level of inter-locus recombination.