Centro de Investigação em Biodiversidade e Recursos Genéticos, Campus Agrário de Vairão, 4485-661 Vairão, Portugal.
BMC Evol Biol. 2011 Oct 8;11:294. doi: 10.1186/1471-2148-11-294.
Since the first report of the antiretroviral restriction factor TRIM5α in primates, several orthologs in other mammals have been described. Recent studies suggest that leporid retroviruses like RELIK, the first reported endogenous lentivirus ever, may have imposed positive selection in TRIM5α orthologs of the European rabbit and European brown hare. Considering that RELIK must already have been present in a common ancestor of the leporid genera Lepus, Sylvilagus and Oryctolagus, we extended the study of evolutionary patterns of TRIM5α to other members of the Leporidae family, particularly to the genus Sylvilagus. Therefore, we obtained the TRIM5α nucleotide sequences of additional subspecies and species of the three leporid genera. We also compared lagomorph TRIM5α deduced protein sequences and established TRIM5α gene and TRIM5α protein phylogenies.
The deduced protein sequence of Iberian hare TRIM5α was 89% identical to European rabbit TRIM5α, although high divergence was observed at the PRYSPRY v1 region between rabbit and the identified alleles from this hare species (allele 1: 50% divergence; allele 2: 53% divergence). A high identity was expected between the Sylvilagus and Oryctolagus TRIM5α proteins and, in fact, the Sylvilagus TRIM5α was 91% identical to the Oryctolagus protein. Nevertheless, the PRYSPRY v1 region was only 50% similar between these genera. Selection analysis of Lagomorpha TRIM5α proteins identified 25 positively-selected codons, 11 of which are located in the PRYSPRY v1 region, responsible for species specific differences in viral capsid recognition.
By extending Lagomorpha TRIM5α studies to an additional genus known to bear RELIK, we verified that the divergent species-specific pattern observed between the Oryctolagus and Lepus PRYSPRY-domains is also present in Sylvilagus TRIM5α. This work is one of the first known studies that compare the evolution of the antiretroviral restriction factor TRIM5α in different mammalian groups, Lagomorpha and Primates.
自灵长类动物中首次报道抗病毒限制因子 TRIM5α 以来，已在其他哺乳动物中描述了几个同源物。最近的研究表明，像 RELIK 这样的兔形目逆转录病毒，即首次报道的内源性慢病毒，可能对欧洲兔和欧洲野兔的 TRIM5α 同源物施加了正选择。考虑到 RELIK 必须已经存在于兔形目兔属、林兔属和穴兔属的共同祖先中，我们将 TRIM5α 的进化模式研究扩展到了兔形目科的其他成员，特别是林兔属。因此，我们获得了三个兔形目属的其他亚种和物种的 TRIM5α 核苷酸序列。我们还比较了兔形目 TRIM5α 推导蛋白序列，并建立了 TRIM5α 基因和 TRIM5α 蛋白系统发育。
伊比利亚兔 TRIM5α 的推导蛋白序列与欧洲兔 TRIM5α 有 89%的同一性，尽管在兔和该兔种鉴定的等位基因之间的 PRYSPRY v1 区域观察到高度分化（等位基因 1：50%分化；等位基因 2：53%分化）。林兔属和穴兔属的 TRIM5α 蛋白之间预计会有很高的同一性，事实上，林兔属的 TRIM5α 与穴兔属的蛋白有 91%的同一性。然而，这些属之间的 PRYSPRY v1 区域仅 50%相似。兔形目 TRIM5α 蛋白的选择分析鉴定了 25 个正选择密码子，其中 11 个位于 PRYSPRY v1 区域，负责病毒衣壳识别的种特异性差异。
通过将兔形目 TRIM5α 的研究扩展到另一个已知携带 RELIK 的属，我们证实了在穴兔属和兔属的 PRYSPRY 结构域之间观察到的分化的种特异性模式也存在于林兔属的 TRIM5α 中。这项工作是比较不同哺乳动物群体（兔形目和灵长目）中抗病毒限制因子 TRIM5α 进化的首批已知研究之一。
