MOLECULAR EVOLUTION OF HUMAN T-CELL LEUKEMIA-VIRUS
MOLECULAR EVOLUTION OF HUMAN T-CELL LEUKEMIA-VIRUS
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DOI：
10.1007/bf02102076
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发表时间：
1990-01-01
影响因子：
3.9
通讯作者：
GOJOBORI, T
中科院分区：
文献类型：
--
作者：
INA, Y;GOJOBORI, T
利用人类T细胞白血病病毒Ⅰ型（HTLV-Ⅰ）长末端重复序列（LTR）和tax基因的核苷酸序列，构建了HTLV-Ⅰ及其相关病毒的系统发育树。这些树显示，这些病毒从一个共同的祖先病毒分化而来，它们被分为两组，其宿主是灵长类动物或牛。然而，病毒的树的拓扑结构与宿主的不同。这表明HTLV-I和HTLV-I相关病毒的进化独立于宿主物种的差异，并且人类和猴子之间的种间传播发生在过去。HTLV-I Tax基因核苷酸多样性为0.025。该值比人类珠蛋白基因的值大10倍以上，但比甲型流感病毒的血凝素基因的值小约20倍。因此，HTLV-I基因的遗传变异性似乎高于核基因，但远低于典型RNA病毒的基因。此外，我们还研究了雷克斯和税收基因重叠区域的功能限制。结果表明，在重叠区，tax基因对氨基酸变化的抑制作用比雷克斯基因强得多。
Phylogenetic trees for the human T-cell leukemia virus type I (HTLV-I) and its related viruses were constructed by use of nucleotide sequences of the long terminal repeat (LTR) and the tax gene. The trees showed that the viruses diverged from a common ancestral virus and that they are classified into two groups whose hosts are either primates or bovines. However, the topology of the trees for the viruses differed from that for the hosts. This suggests that HTLV-I and HTLV-I-related viruses evolved independently of host-species divergence and that interspecies transmission between human and monkeys occurred in the past. The nucleotide diversity of the tax genes of HTLV-I was estimated to be 0.025. This value is more than 10 times larger than that of human globin genes, but it is about 20 times smaller than that of hemagglutinin genes of influenza A viruses. Thus, the genetic variability of the HTLV-I genes seems to be higher than that of nuclear genes but much lower than the genes of typical RNA viruses. Furthermore, we examined functional constraints on the overlapping region of the rex and tax genes. The results obtained imply that for the overlapping region, the tax gene has much stronger constraints against amino acid changes than the rex gene.