Evolution of olfactory receptor genes in the human genome
Evolution of olfactory receptor genes in the human genome
复制标题
DOI：
10.1073/pnas.1635157100
复制
发表时间：
2003-10-14
影响因子：
11.1
通讯作者：
Nei, M
中科院分区：
文献类型：
--
作者：
Niimura, Y;Nei, M
嗅觉受体（OR）基因构成了人类基因组中已知最大的多基因家族。为了深入了解它们的进化历史，我们从最新的人类基因组序列中确定了完整的OR基因集及其染色体位置。我们检测到388个具有完整开放阅读框的潜在功能基因和414个明显的假基因。功能基因的数量和比例（48%）比之前报道的要大得多。如先前所述，人类OR基因可明确分为I类和II类基因。我们的系统发育分析表明，II类OR基因可进一步分为19个由高自展值支持的系统发育分支。我们还发现有许多在系统发育上密切相关的OR基因串联排列。这些基因似乎是由串联基因复制产生的。然而，基因组簇与系统发育分支之间的关系非常复杂。有大量情况是同一系统发育分支中的基因位于不同的染色体区域。此外，属于远缘系统发育分支的OR基因有时在染色体区域中紧密相邻，形成紧密的基因组簇。这些观察结果可以通过以下假设来解释：在OR基因簇区域发生了若干染色体重排，并且不同基因组簇中包含的OR基因发生了重排。
Olfactory receptor (OR) genes form the largest known multigene family in the human genome. To obtain some insight into their evolutionary history, we have identified the complete set of OR genes and their chromosomal locations from the latest human genome sequences. We detected 388 potentially functional genes that have intact ORFs and 414 apparent pseudogenes. The number and the fraction (48%) of functional genes are considerably larger than the ones previously reported. The human OR genes can clearly be divided into class I and class II genes, as was previously noted. Our phylogenetic analysis has shown that the class II OR genes can further be classified into 19 phylogenetic clacles supported by high bootstrap values. We have also found that there are many tandem arrays of OR genes that are phylogenetically closely related. These genes appear to have been generated by tandem gene duplication. However, the relationships between genomic clusters and phylogenetic clacles are very complicated. There are a substantial number of cases in which the genes in the same phylogenetic clade are located on different chromosomal regions. In addition, OR genes belonging to distantly related phylogenetic clacles are sometimes located very closely in a chromosomal region and form a tight genomic cluster. These observations can be explained by the assumption that several chromosomal rearrangements have occurred at the regions of OR gene clusters and the OR genes contained in different genomic clusters are shuffled.