Prevalence of viral photosynthesis genes along a freshwater to saltwater transect in Southeast USA
Prevalence of viral photosynthesis genes along a freshwater to saltwater transect in Southeast USA
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DOI：
10.1111/1758-2229.12780
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发表时间：
2019-07-16
影响因子：
3.3
通讯作者：
Konstantinidis, Konstantinos T.
中科院分区：
文献类型：
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作者：
Ruiz-Perez, Carlos A.;Tsementzi, Despina;Konstantinidis, Konstantinos T.
噬菌体编码宿主获得的功能基因，称为辅助代谢基因（AMGs）。光合作用AMGs通常存在于海洋感染蓝藻的Myoviridae和Podoviridae噬藻体中，但它们在淡水环境中的生态学研究尚不充分。为了进一步了解这一问题，我们分析了四年来夏季从美国东南部查塔胡奇河相连的五个湖泊和两个河口收集的病毒宏基因组。十个不同amg的序列被恢复，并发现在所有地点普遍存在。大多数淡水AMGs的丰度比河口和海洋AMGs少10倍，由新型肌病毒科和足病毒科噬藻属编码。值得注意的是，一些相应的病毒基因组显示出沿江特定省份的地方性。这转化为psbA基因的系统发育聚类模式，与海洋和淡水来源相匹配，表明psbA可能作为一种强大的分类和来源跟踪生物标志物。以分离物S-EIVl为代表的新型病毒谱系中含有psbA，这在该谱系中是前所未有的。总之，我们的研究结果表明，光合作用AMGs的获取是水生生态系统中噬藻体广泛使用的策略，并进一步表明存在病毒省，其中某些病毒物种和/或基因型在当地丰富。
Bacteriophages encode host-acquired functional genes known as auxiliary metabolic genes (AMGs). Photosynthesis AMGs are commonly found in marine cyanobacteria-infecting Myoviridae and Podoviridae cyanophages, but their ecology remains understudied in freshwater environments. To advance knowledge of this issue, we analysed viral metagenomes collected in the summertime for four years from five lakes and two estuarine locations interconnected by the Chattahoochee River, Southeast USA. Sequences representing ten different AMGs were recovered and found to be prevalent in all sites. Most freshwater AMGs were 10-fold less abundant than estuarine and marine AMGs and were encoded by novel Myoviridae and Podoviridae cyanophage genera. Notably, several of the corresponding viral genomes showed endemism to a specific province along the river. This translated into psbA gene phylogenetic clustering patterns that matched a marine vs. freshwater origin indicating that psbA may serve as a robust classification and source-tracking biomarker. Genomes classified in a novel viral lineage represented by isolate S-EIVl contained psbA, which is unprecedented for this lineage. Collectively, our findings indicated that the acquisition of photosynthesis AMGs is a widespread strategy used by cyanophages in aquatic ecosystems, and further indicated the existence of viral provinces in which certain viral species and/or genotypes are locally abundant.