Bénit Laurence, Calteau Alexandra, Heidmann Thierry
Unité des Rétrovirus Endogènes et Eléments Rétroïdes des Eucaryotes Supérieurs, UMR 8122 CNRS, Institut Gustave Roussy, 39 rue Camille Desmoulins, 94805 Villejuif Cedex, France.
Virology. 2003 Jul 20;312(1):159-68. doi: 10.1016/s0042-6822(03)00163-6.
In a previous search based on the envelope gene, we had identified two related proviral elements that could not be included in identified ERV families. An in silico database screening associated with an in vivo polymerase chain reaction search using primers in the reverse transcriptase domain, now allowed identification of a series of related elements, found at a limited number in simians. A phylogenetic analysis led to their inclusion in a new family of endogenous retroviruses with limited expansion, which we named ERV-Fc, and which is part of the enlarged ERV-F/H family. The human genome comprises only six HERV-Fc, among which two possess full-length coding envelope genes. A complete provirus was identified in the baboon, also disclosing a fully open envelope gene. Cloning of the sites orthologous to the envelope-coding human proviruses demonstrated presence of the integrated proviruses in chimpanzee and gorilla, but not in orangutan. For the baboon element, the orthologous locus was found empty even in the phylogenetically most closely related macaque, again suggesting, together with the complete identity of its LTRs, "recent" integration. The data presented are compatible with an evolutionary scheme in which the ERV-Fc proviruses would be the endogenous traces of an active retroviral element, possibly acting as an infectious retrovirus with low endogeneization potency, with evidence for integrations at two distinct periods of primate evolution.
在之前基于包膜基因的搜索中，我们鉴定出两个相关的前病毒元件，它们无法归入已确定的ERV家族。通过计算机数据库筛选，并结合使用逆转录酶结构域中的引物进行体内聚合酶链反应搜索，现在得以鉴定出一系列相关元件，这些元件在猿猴中数量有限。系统发育分析将它们归入一个新的内源性逆转录病毒家族，该家族扩张有限，我们将其命名为ERV-Fc，它是扩大后的ERV-F/H家族的一部分。人类基因组仅包含六个HERV-Fc，其中两个拥有全长编码包膜基因。在狒狒中鉴定出一个完整的前病毒，其包膜基因也完全开放。对与编码包膜的人类前病毒直系同源位点的克隆表明，黑猩猩和大猩猩中存在整合的前病毒，但猩猩中没有。对于狒狒元件，即使在系统发育上最密切相关的猕猴中，直系同源位点也是空的，这与它的LTR完全相同一起再次表明是“近期”整合。所呈现的数据与一种进化模式相符，即ERV-Fc前病毒可能是一种活跃逆转录病毒元件的内源性痕迹，可能作为一种内源性化能力较低的传染性逆转录病毒，有证据表明在灵长类进化的两个不同时期发生了整合。
