Genome sequences of the first Autographiviridae phages infecting marine Roseobacter

Abstract

The ubiquitous and abundant marine phages play critical roles in shaping the composition and function of bacterial communities, impacting biogeochemical cycling in marine ecosystems. Autographiviridae is among the most abundant and ubiquitous phage families in the ocean. However, studies on the diversity and ecology of Autographiviridae phages in marine environments are restricted to isolates that infect SAR11 bacteria and cyanobacteria. In this study, ten new roseophages that infect marine Roseobacter strains were isolated from coastal waters. These new roseophages have a genome size ranging from 38 917 to 42 634 bp and G+C content of 44.6–50 %. Comparative genomics showed that they are similar to known Autographiviridae phages regarding gene content and architecture, thus representing the first Autographiviridae roseophages. Phylogenomic analysis based on concatenated conserved genes showed that the ten roseophages form three distinct subgroups within the Autographiviridae, and sequence analysis revealed that they belong to eight new genera. Finally, viromic read-mapping showed that these new Autographiviridae phages are widely distributed in global oceans, mostly inhabiting polar and estuarine locations. This study has expanded the current understanding of the genomic diversity, evolution and ecology of Autographiviridae phages and roseophages. We suggest that Autographiviridae phages play important roles in the mortality and community structure of roseobacters, and have broad ecological applications.

Novel phage infecting the Roseobacter CHUG lineage reveals a diverse and globally distributed phage family

“…Currently, more than 64 phages that infect diverse Roseobacter lineages have been reported ( 20 , 22 , 23 , 33 – 38 ). Comparative genomic analysis classified the isolated roseophages into 16 groups.…”

“…Comparative genomic analysis classified the isolated roseophages into 16 groups. Although most roseophages were isolated on copiotrophic roseobacters that could proliferate on nutrient-rich plates ( 33 – 36 ), some roseophages infecting the oligotrophic PRC members have recently been reported ( 20 , 22 , 23 , 37 , 38 ). These PRC phages form six clades and are diverse, abundant, and widely distributed in oceans ( 20 , 22 , 23 , 37 , 38 ).…”

“…Although most roseophages were isolated on copiotrophic roseobacters that could proliferate on nutrient-rich plates ( 33 – 36 ), some roseophages infecting the oligotrophic PRC members have recently been reported ( 20 , 22 , 23 , 37 , 38 ). These PRC phages form six clades and are diverse, abundant, and widely distributed in oceans ( 20 , 22 , 23 , 37 , 38 ). Among them, one roseophage infecting CHUG member has been recently isolated and represents the first roseophage of the family Autographiviridae ( 38 ).…”

“…These PRC phages form six clades and are diverse, abundant, and widely distributed in oceans ( 20 , 22 , 23 , 37 , 38 ). Among them, one roseophage infecting CHUG member has been recently isolated and represents the first roseophage of the family Autographiviridae ( 38 ).…”