Evolution of the Phosphoglycerate mutase processed gene in human and chimpanzee revealing the origin of a new primate gene
Evolution of the Phosphoglycerate mutase processed gene in human and chimpanzee revealing the origin of a new primate gene
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DOI：
10.1093/oxfordjournals.molbev.a004124
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发表时间：
2002-05-01
影响因子：
10.7
通讯作者：
Long, MY
中科院分区：
文献类型：
--
作者：
Betrán, E;Wang, W;Long, MY
加工基因是由表达基因的信使RNA通过逆转录产生的。人类基因组中基因的加工拷贝的估计数量为10，000 - 14，000。其中一些可能是假基因，具有非功能序列的预期模式，但其他一些可能是新基因的重要来源。我们已经研究了在人类中描述的磷酸甘油酸酯酶加工基因（PGAM 3）的进化，并认为这是一个假基因。我们对黑猩猩和猕猴的PGAM 3基因进行了测序，获得了人类PGAM 3基因编码区的多态性数据。我们发现了PGAM 3可能产生功能蛋白的证据，作为解决人类加工假基因功能的一个例子。首先，开放阅读框架是完整的，尽管在3'非翻译区发生了许多缺失。第二，基因表达。终于来了PGAM 3的种间和种内变异与假基因的中性模型不一致，表明一个新的功能性灵长类基因已经起源。PGAM 3基因的氨基酸差异显著高于同义差异，支持正选择作用于该基因。在群体遗传分析中，稀有等位基因的过量进一步支持了选择的作用。因此，PGAM 3位于非常低重组的区域。可以想象的是，在这个新出现的基因中的快速固定事件可能有助于该区域中变异的选择性扫描。
Processed genes are created by retroposition from messenger RNA of expressed genes. The estimated amount of processed copies of genes in the human genome is 10,000-14,000. Some of these might be pseudogenes with the expected pattern for nonfunctional sequences, but some others might be an important Source of new genes. We have studied the evolution of a Phosphoglycerate mutase processed gene (PGAM3) described in humans and believed to be a pseudogene. We sequenced PGAM3 in chimpanzee and macaque and obtained polymorphism data for human coding region. We found evidence that PGAM3 likely produces a functional protein, as an example of addressing functionality for human processed pseudogenes. First, the open reading frame was intact despite many deletions that occurred in the 3' untranslated region. Second, it appears that the gene is expressed. Finally. interspecies and intraspecies variation for PGAM3 was not consistent with the neutral model proposed for pseudogenes, suggesting that a new functional primate gene has originated. Amino acid divergence was significantly higher than synonymous divergence in PGAM3 lineage, supporting positive selection acting in this gene. This role of selection was further supported by the excess of rare alleles in a Population genetic analysis. PGAM3 is located in a region of very low recombination: therefore. it is conceivable that the rapid fixation events in this newly arising gene may have contributed to a selective sweep of variation in the region.