Mol Biol Evol. 2011 Jan;28(1):13-5. doi: 10.1093/molbev/msq218. Epub 2010 Aug 16.
Alu is a predominant short interspersed element (SINE) family in the human genome and consists of two monomer units connected by an A-rich linker. At present, dimeric Alu elements are active in humans, but Alu monomers are present as fossilized sequences. A comparative genome analysis of human and chimpanzee genomes revealed eight recent insertions of Alu monomers. One of them was a retroposed product of another Alu monomer with 3' transduction. Further analysis of 1,404 loci of the Alu monomer in the human genome revealed that some Alu monomers were recently generated by recombination between the internal and 3' A-rich tracts inside of dimeric Alu elements. The data show that Alu monomers were generated by 1) retroposition of other Alu monomers and 2) recombination between two A-rich tracts.
Alu 是人类基因组中主要的短散在重复元件（SINE）家族，由两个单体单元通过富含 A 的连接子连接而成。目前，二聚体 Alu 元件在人类中具有活性，但 Alu 单体则以化石序列的形式存在。对人类和黑猩猩基因组的比较基因组分析显示，有 8 个 Alu 单体的近期插入。其中之一是另一个 Alu 单体的 3'转导的逆转录产物。对人类基因组中 Alu 单体的 1404 个位点的进一步分析表明，一些 Alu 单体是由二聚体 Alu 元件内部的内部和 3'富含 A 的片段之间的重组产生的。这些数据表明，Alu 单体是通过 1）其他 Alu 单体的逆转录和 2）两个富含 A 的片段之间的重组产生的。
