Mol Biol Evol. 2011 Jan;28(1):33-7. doi: 10.1093/molbev/msq260. Epub 2010 Oct 1.
Retroposition, a leading mechanism for gene duplication, is an important process shaping the evolution of genomes. Retrogenes are also involved in the gene structure evolution as a major player in the process of intron deletion. Here, we demonstrate the role of retrogenes in intron gain in mammals. We identified one case of "intronization," the transformation of exonic sequences into an intron, in the primate specific retrogene RNF113B and two independent "intronization" events in the retrogene DCAF12L2, one in the common ancestor of primates and rodents and another one in the rodent lineage. Intron gain resulted from the origin of new splice variants, and both genes have two transcript forms, one with retained intron and one with the intron spliced out. Evolution of these genes, especially RNF113B, has been very dynamic and has been accompanied by several additional events including parental gene loss, secondary retroposition, and exaptation of transposable elements.
反转录转座，一种主要的基因复制机制，是塑造基因组进化的重要过程。反转录基因也参与了基因结构的进化，作为内含子缺失过程中的主要参与者。在这里，我们证明了反转录基因在哺乳动物中内含子获得中的作用。我们在灵长类特异性反转录基因 RNF113B 中发现了一个“内含子化”的例子，即将外显子序列转化为内含子，在 DCAF12L2 反转录基因中发现了两个独立的“内含子化”事件，一个发生在灵长类和啮齿动物的共同祖先中，另一个发生在啮齿动物谱系中。内含子的获得源于新剪接变体的起源，这两个基因都有两种转录形式，一种保留内含子，另一种内含子被剪接出去。这些基因的进化非常活跃，伴随着几个额外的事件，包括亲本基因的丢失、二次反转录和转座元件的适应。
