Department of Human Genetics, Center of Human and Molecular Biology, Medical Faculty, University of Saarland, 66421 Homburg, Germany.
Virology. 2013 Aug 15;443(1):1-10. doi: 10.1016/j.virol.2013.05.008. Epub 2013 May 29.
Transcriptome analysis of polar bears (Ursus maritimus) yielded sequences with highest similarity to the human endogenous retrovirus group HERV-K(HML-2). Further analysis of the polar bear draft genome identified an endogenous betaretrovirus group comprising 26 proviral copies and 231 solo LTRs. Molecular dating indicates the group originated before the divergence of bears from a common ancestor but is not present in all carnivores. Closely related sequences were identified in the giant panda (Ailuropoda melanoleuca) and characterized from its genome. We have designated the polar bear and giant panda sequences U. maritimus endogenous retrovirus (UmaERV) and A. melanoleuca endogenous retrovirus (AmeERV), respectively. Phylogenetic analysis demonstrated that the bear virus group is nested within the HERV-K supergroup among bovine and bat endogenous retroviruses suggesting a complex evolutionary history within the HERV-K group. All individual remnants of proviral sequences contain numerous frameshifts and stop codons and thus, the virus is likely non-infectious.
对北极熊（Ursus maritimus）的转录组分析产生了与人类内源性逆转录病毒组 HERV-K（HML-2）最相似的序列。对北极熊草案基因组的进一步分析确定了一个内源性β逆转录病毒组，包括 26 个前病毒拷贝和 231 个 solo LTR。分子年代测定表明，该组起源于熊类与共同祖先分化之前，但并非存在于所有食肉动物中。在大熊猫（Ailuropoda melanoleuca）中鉴定出了密切相关的序列，并从其基因组中进行了特征描述。我们分别将北极熊和大熊猫序列命名为 Ursus maritimus 内源性逆转录病毒（UmaERV）和 Ailuropoda melanoleuca 内源性逆转录病毒（AmeERV）。系统发育分析表明，熊类病毒组嵌套在牛和蝙蝠内源性逆转录病毒的 HERV-K 超组内，表明 HERV-K 组内存在复杂的进化历史。所有前病毒序列的个体残余物都包含大量移码和终止密码子，因此，该病毒可能是非感染性的。
