Koga A, Shimada A, Shima A, Sakaizumi M, Tachida H, Hori H
Division of Biological Sciences, Graduate School of Science, Nagoya University, Nagoya 464-8602, Japan.
Genetics. 2000 May;155(1):273-81. doi: 10.1093/genetics/155.1.273.
Tol2 is a transposable element of the terminal-inverted-repeat class, residing in the genome of the medaka fish Oryzias latipes. The genus Oryzias contains more than 10 species for which phylogenetic relationships have previously been estimated. To infer the history of Tol2 in this genus we performed genomic Southern blots and PCR analyses of 10 of the species. It was revealed that Tol2 occurs in 2 of the 10 species (O. curvinotus and O. latipes) and that the length and the restriction map structure of Tol2 are identical in the two cases. Further, sequencing analysis revealed an extremely low level of divergence compared with that in a nuclear gene. These results suggest recent incorporation of Tol2 into one or both of the two species, implying horizontal transfer of Tol2 from one species to the other or into them both from a common source.
Tol2是一种末端反向重复类转座元件，存在于青鳉鱼（Oryzias latipes）的基因组中。青鳉属包含10多个物种，此前已对它们的系统发育关系进行了估计。为了推断该属中Tol2的历史，我们对其中10个物种进行了基因组Southern杂交和PCR分析。结果显示，Tol2存在于10个物种中的2个（弯背青鳉和青鳉），并且在这两种情况下Tol2的长度和限制性图谱结构相同。此外，测序分析显示，与核基因相比，其分歧水平极低。这些结果表明Tol2是最近才整合到这两个物种中的一个或两个物种中，这意味着Tol2是从一个物种水平转移到另一个物种，或者是从一个共同来源水平转移到这两个物种中。
