Masui S, Kamoda S, Sasaki T, Ishikawa H
Department of Biological Sciences, Graduate School of Science, University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
J Mol Evol. 2000 Nov;51(5):491-7. doi: 10.1007/s002390010112.
Wolbachia are obligatory intracellular and maternally inherited bacteria, known to infect many species of arthropod. In this study, we discovered a bacteriophage-like genetic element in Wolbachia, which was tentatively named bacteriophage WO. The phylogenetic tree based on phage WO genes of several Wolbachia strains was not congruent with that based on chromosomal genes of the same strains, suggesting that phage WO was active and horizontally transmitted among various Wolbachia strains. All the strains of Wolbachia used in this study were infected with phage WO. Although the phage genome contained genes of diverse origins, the average G+C content and codon usage of these genes were quite similar to those of a chromosomal gene of Wolbachia. These results raised the possibility that phage WO has been associated with Wolbachia for a very long time, conferring some benefit to its hosts. The evolution and possible roles of phage WO in various reproductive alterations of insects caused by Wolbachia are discussed.
沃尔巴克氏体是一类必需在细胞内寄生且通过母体遗传的细菌，已知可感染多种节肢动物。在本研究中，我们在沃尔巴克氏体中发现了一种类似噬菌体的遗传元件，暂命名为噬菌体WO。基于几种沃尔巴克氏体菌株的噬菌体WO基因构建的系统发育树与基于相同菌株染色体基因构建的系统发育树不一致，这表明噬菌体WO具有活性且能在不同的沃尔巴克氏体菌株间水平传播。本研究中使用的所有沃尔巴克氏体菌株都感染了噬菌体WO。尽管噬菌体基因组包含多种来源的基因，但其这些基因的平均G+C含量和密码子使用情况与沃尔巴克氏体的一个染色体基因非常相似。这些结果增加了噬菌体WO与沃尔巴克氏体长期相关联并为其宿主带来某些益处的可能性。本文讨论了噬菌体WO在由沃尔巴克氏体引起的昆虫各种生殖改变中的进化及可能作用。
