Makarova K S, Vul'f Iu I, Seledtsov I A, Ratner V A
Genetika. 1995 Dec;31(12):1614-29.
Transposons of gypsy group are assigned to LTR-containing retrotransposons present in the genomes of invertebrates, fungi, and plants. In this work, a theoretical analysis of the potential products of ORFs of these retrotranposons was conducted. Alignments were obtained and trees of similarity were constructed for domains of the POL region. On the basis of the obtained data, two hypothetically monophyletic subgroups of transposons were distinguished within the framework of the gypsy group, settling the genomes of taxonomically related organisms (the subgroup of "true" gypsy of insects and the subgroup of gypsy-like transposons of plants and fungi). A number of peculiarities of the topology of these trees hypothetically indicate cases of genetic conversion and recombination of domains accompanying the evolution of this group. The amino acid substitution fixation rate was evaluated on the basis of comparison of sequences of the protein products of ORFs. Estimates of the time of divergence of subgroups of gypsy-group transposons are significantly less than estimates of the times of divergence of their host species. One explanation for this discrepancy might be the hypothesis of settlement by transposons of the genomes of isolated host species.
吉普赛族转座子属于存在于无脊椎动物、真菌和植物基因组中的含长末端重复序列（LTR）的逆转录转座子。在这项工作中，对这些逆转录转座子开放阅读框（ORF）的潜在产物进行了理论分析。获得了比对结果，并构建了POL区域各结构域的相似性树。基于所获得的数据，在吉普赛族框架内区分出两个假设的单系转座子亚组，它们存在于分类学上相关生物的基因组中（昆虫的“真正”吉普赛亚组以及植物和真菌的类吉普赛转座子亚组）。这些树的拓扑结构的一些特性假设性地表明了伴随该类群进化的结构域遗传转化和重组的情况。基于ORF蛋白质产物序列的比较评估了氨基酸替代固定率。吉普赛族转座子亚组的分歧时间估计值明显小于其宿主物种的分歧时间估计值。这种差异的一种解释可能是转座子定居于孤立宿主物种基因组的假说。
