Tan Bing, Yang Xing-Lou, Ge Xing-Yi, Peng Cheng, Liu Hai-Zhou, Zhang Yun-Zhi, Zhang Li-Biao, Shi Zheng-Li
University of Chinese Academy of Sciences, Beijing, PR China.
CAS Key Laboratory of Special Pathogens and Biosafety, Center for Emerging Infectious Diseases of Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, PR China.
J Gen Virol. 2017 Apr;98(4):739-748. doi: 10.1099/jgv.0.000739.
Bats have been reported to carry diverse adenoviruses. However, most bat adenoviruses have been identified on the basis of partial genome sequences, and knowledge on the evolution of bat adenoviruses remains limited. In this study, we isolated and characterized four novel adenoviruses from two distinct bat species, and their full-length genomes were sequenced. Sequence analysis revealed that these isolates represented three distinct species of the genus Mastadenovirus. However, all isolates had an exceptionally low G+C content and relatively short genomes compared with other known mastadenoviruses. We further analysed the relationships among the G+C content, 5'-C-phosphate-G-3' (CpG) representation and genome size in the family Adenoviridae. Our results revealed that the CpG representation in adenoviral genomes depends primarily on the level of methylation, and the genome size displayed significant positive correlations with both G+C content and CpG representation. Since ancestral adenoviruses are believed to have contained short genomes, those probably had a low G+C content, similar to the genomes of these bat strains. Our results suggest that bats are important natural reservoirs for adenoviruses and play important roles in the evolution of adenoviruses.
据报道，蝙蝠携带多种腺病毒。然而，大多数蝙蝠腺病毒是基于部分基因组序列鉴定出来的，关于蝙蝠腺病毒进化的知识仍然有限。在本研究中，我们从两种不同的蝙蝠物种中分离并鉴定了四种新型腺病毒，并对它们的全长基因组进行了测序。序列分析表明，这些分离株代表了哺乳动物腺病毒属的三个不同物种。然而，与其他已知的哺乳动物腺病毒相比，所有分离株的G+C含量都异常低，基因组也相对较短。我们进一步分析了腺病毒科中G+C含量、5'-C-磷酸-G-3'（CpG）表现形式和基因组大小之间的关系。我们的结果表明，腺病毒基因组中的CpG表现形式主要取决于甲基化水平，基因组大小与G+C含量和CpG表现形式均呈显著正相关。由于据信祖先腺病毒含有短基因组，那些基因组可能具有低G+C含量，类似于这些蝙蝠毒株的基因组。我们的结果表明，蝙蝠是腺病毒的重要天然宿主，在腺病毒的进化中发挥着重要作用。
