Extensive gains and losses of olfactory receptor genes in mammalian evolution.
Extensive gains and losses of olfactory receptor genes in mammalian evolution.
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DOI：
10.1371/journal.pone.0000708
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发表时间：
2007-08-08
期刊：
影响因子：
3.7
通讯作者：
Nei, Masatoshi
中科院分区：
文献类型：
--
作者：
Niimura, Yoshihito;Nei, Masatoshi
哺乳动物的嗅觉是由一个多基因家族的嗅觉受体（OR）基因介导的。OR基因的数量在不同种类的哺乳动物中差异很大，大多数物种都有大量的假基因。为了深入了解哺乳动物OR基因的进化动力学，我们鉴定了鸭嘴兽、负鼠、牛、狗、大鼠和猕猴的整套OR基因，并与人类和小鼠的基因一起研究了这些基因的进化变化。我们发现鸭嘴兽和灵长类动物有<400个功能性OR基因，而其他物种有800- 1，200个功能性OR基因。然后，我们估计了哺乳动物系统发育树的每个分支的OR基因的获得和丢失的数量。这项分析表明，（i）胎盘谱系每次从单孔目动物和有袋类动物分化后都会发生基因扩增，（ii）数百个OR基因的获得和丢失以特定的方式发生，使基因库在不同的目的中高度可变。似乎OR基因的数量主要取决于每个物种的功能需求，但一旦数量达到所需水平，它就会因基因的随机复制和缺失而波动。这种波动似乎是由于OR基因表达的随机性。
Odor perception in mammals is mediated by a large multigene family of olfactory receptor (OR) genes. The number of OR genes varies extensively among different species of mammals, and most species have a substantial number of pseudogenes. To gain some insight into the evolutionary dynamics of mammalian OR genes, we identified the entire set of OR genes in platypuses, opossums, cows, dogs, rats, and macaques and studied the evolutionary change of the genes together with those of humans and mice. We found that platypuses and primates have <400 functional OR genes while the other species have 800–1,200 functional OR genes. We then estimated the numbers of gains and losses of OR genes for each branch of the phylogenetic tree of mammals. This analysis showed that (i) gene expansion occurred in the placental lineage each time after it diverged from monotremes and from marsupials and (ii) hundreds of gains and losses of OR genes have occurred in an order-specific manner, making the gene repertoires highly variable among different orders. It appears that the number of OR genes is determined primarily by the functional requirement for each species, but once the number reaches the required level, it fluctuates by random duplication and deletion of genes. This fluctuation seems to have been aided by the stochastic nature of OR gene expression.
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影响因子：
3.7
作者：
Demuth JP;De Bie T;Stajich JE;Cristianini N;Hahn MW
通讯作者：
Hahn MW
DOI：
10.1073/pnas.0307882100
发表时间：
2004-02-24
影响因子：
11.1
作者：
Malnic, B;Godfrey, PA;Buck, LB
通讯作者：
Buck, LB
人类，狗和小鼠的系统基因组研究。
影响因子：
4.3
作者：
Cannarozzi, Gina;Schneider, Adrian;Gonnet, Gaston
通讯作者：
Gonnet, Gaston
DOI：
10.1073/pnas.0501589102
发表时间：
2005-04-19
影响因子：
11.1
作者：
Grus, WE;Shi, P;Zhang, JZ
通讯作者：
Zhang, JZ
影响因子：
10.7
作者：
Nam, J;Nei, M
通讯作者：
Nei, M