Tristem M, Kabat P, Herniou E, Karpas A, Hill F
Department of Biology, Imperial College, Ascot, Berkshire, UK.
Mol Gen Genet. 1995 Nov 15;249(2):229-36. doi: 10.1007/BF00290370.
Despite the close similarities between retroviruses and the gypsy/Ty3 group of LTR-retrotransposons their host ranges are largely distinct: the retroviruses are found only in vertebrates, whereas the gypsy LTR-retrotransposons are almost exclusively restricted to invertebrates, plants and fungi. Here we report the amplification by PCR, and characterisation, of one of the first LTR-retrotransposons to be discovered in vertebrates--in several members of the piscine family Salmonidae. Phylogenetic analysis of this retroelement, termed easel, indicates that it is probably a phylogeneticaly basal member of the gypsy group of LTR-retrotransposons and occurs in some of the same species from which retroviruses have previously been isolated. Thus some members of the Salmonidae are the first organisms known to harbour both retroviral branch elements and the gypsy LTR-retrotransposon branch elements. This creates an overlap in the host ranges of the two retroelement families.
尽管逆转录病毒与LTR逆转座子的吉普赛/Ty3组之间存在密切相似性，但它们的宿主范围却大不相同：逆转录病毒仅在脊椎动物中发现，而吉普赛LTR逆转座子几乎只限于无脊椎动物、植物和真菌。在此我们报告了通过PCR扩增并鉴定了在脊椎动物中发现的首批LTR逆转座子之一——在鲑科鱼类的几个成员中。对这种名为画架的逆转座子进行系统发育分析表明，它可能是LTR逆转座子吉普赛组的一个系统发育基础成员，并且出现在一些先前已分离出逆转录病毒的相同物种中。因此，鲑科的一些成员是已知同时携带逆转录病毒分支元件和吉普赛LTR逆转座子分支元件的首批生物。这在两个逆转座子家族的宿主范围中产生了重叠。
