Laboratory of Cellular and Molecular Biology, National Institute on Aging/National Institutes of Health, 251 Bayview Blvd., Suite 100, Baltimore, MD 21224, USA.
Semin Immunol. 2010 Feb;22(1):10-6. doi: 10.1016/j.smim.2009.11.004. Epub 2009 Dec 9.
The recombination activating genes 1 and 2 (Rag1 and Rag2) encode the key enzyme that is required for the generation of the highly diversified antigen receptor repertoire central to adaptive immunity. The longstanding model proposed that this gene pair was acquired by horizontal gene transfer to explain its abrupt appearance in the vertebrate lineage. The analyses of the enormous amount of sequence data created by many genome sequencing projects now provide the basis for a more refined model as to how this unique gene pair evolved from a selfish DNA transposon into a sophisticated DNA recombinase essential for immunity.
重组激活基因 1 和 2(Rag1 和 Rag2)编码的关键酶对于产生高度多样化的抗原受体库至关重要,而这些受体库是适应性免疫的核心。长期以来,人们一直认为这对基因是通过水平基因转移获得的,这一假说旨在解释其在脊椎动物谱系中的突然出现。许多基因组测序项目所产生的大量序列数据的分析,为这对独特的基因如何从自私的 DNA 转座子进化为免疫必需的复杂 DNA 重组酶提供了更精细的模型。