基因復(fù)制是產(chǎn)生新基因和引發(fā)基因組革新的一種重要機(jī)制。轉(zhuǎn)位子介導(dǎo)的序列轉(zhuǎn)換（Retrotransposon-mediated sequence transduction，生物通編者譯，如轉(zhuǎn)位子在運動過程中會攜帶其側(cè)翼序列（flanking sequence））是一種已經(jīng)被認(rèn)可的基因復(fù)制機(jī)制。
L1 exon（外顯子）重排（shuffling ）潛能曾經(jīng)在細(xì)胞培植測試（cell culture assays）中有過報道，而且在培養(yǎng)細(xì)胞的基因組中也鑒別出兩種潛在的L1介導(dǎo)的外顯子重排事件。SVA是靈長類一種年輕的轉(zhuǎn)位子家族,，并且其3’側(cè)翼序列在轉(zhuǎn)位過程中能夠進(jìn)行轉(zhuǎn)換。
最近,，路易斯安娜州立大學(xué)BioModular Multi-Scale Systems中心研究員邢錦川（Jinchuan Xing,，音譯）、王慧（Hui Wang,，音譯）對人類基因組中全部的全長SVA元件進(jìn)行了檢測,，評估SVA介導(dǎo)的3’端序列轉(zhuǎn)換的頻率和影響。研究詳細(xì)結(jié)果刊登于11月21日電子版PNAS,。
結(jié)果顯示,，約有53kb的基因組序列是由143種不同的SVA介導(dǎo)的轉(zhuǎn)換事件復(fù)制得到的。特別是,，在人類和非洲人猿（African great apes）分道揚鑣以前,，一組SVA元件通過SVA介導(dǎo)的轉(zhuǎn)換事件，將整個AMAC基因在人類基因組中復(fù)制了三次,。作為對原始AMAC基因的補(bǔ)充,，三次轉(zhuǎn)換的AMAC拷貝包含了完整的ORF（開放閱讀框），至少有兩個在不同的人類組織中轉(zhuǎn)錄活躍,。新復(fù)制的整個基因和通過轉(zhuǎn)位介導(dǎo)的序列轉(zhuǎn)換產(chǎn)生先前未曾描述過的基因家族，代表了可移動元件影響宿主基因組的一種重要的機(jī)制,。
英文原文：
Emergence of primate genes by retrotransposon-mediated sequence transduction
Department of Biological Sciences, Biological Computation and Visualization Center, Center for BioModular Multi-Scale Systems, Louisiana State University, 202 Life Sciences Building, Baton Rouge, LA 70803; and Tulane Cancer Center SL-66, Department of Environmental Health Sciences, Tulane University Health Sciences Center, New Orleans, LA 70112
Edited by Susan R. Wessler, University of Georgia, Athens, GA, and approved June 28, 2006 (received for review April 20, 2006)
Gene duplication is one of the most important mechanisms for creating new genes and generating genomic novelty. Retrotransposon-mediated sequence transduction (i.e., the process by which a retrotransposon carries flanking sequence during its mobilization) has been proposed as a gene duplication mechanism. L1 exon shuffling potential has been reported in cell culture assays, and two potential L1-mediated exon shuffling events have been identified in the genome. SVA is the youngest retrotransposon family in primates and is capable of 3' flanking sequence transduction during retrotransposition. In this study, we examined all of the full-length SVA elements in the human genome to assess the frequency and impact of SVA-mediated 3' sequence transduction. Our results showed that 53 kb of genomic sequences have been duplicated by 143 different SVA-mediated transduction events. In particular, we identified one group of SVA elements that duplicated the entire AMAC gene three times in the human genome through SVA-mediated transduction events, which happened before the divergence of humans and African great apes. In addition to the original AMAC gene, the three transduced AMAC copies contain intact ORFs in the human genome, and at least two are actively transcribed in different human tissues. The duplication of entire genes and the creation of previously undescribed gene families through retrotransposon-mediated sequence transduction represent an important mechanism by which mobile elements impact their host genomes.
