dsDNA Phage Andromeda with Quasispecies-like Genomic Hypervariability Establishes a Novel Phylogenetic Branch Within the Autographivirinae Subfamily

A new lytic phage Andromeda, specific to the economically important plant pathogen Pseudomonas syringae was isolated. It belongs to the Podoviridae family, Autographivirinae subfamily and possesses a linear dsDNA genome of 40,008 bp with four localized nicks. We reveal that Andromeda represents an atypical member of the phiKMVlviruses and establish a novel group of Andromeda-related phages within the Autographivirinae designated as the ExophiKMVviruses. The ExophiKMVviruses were revealed to share conservation of gene order and products with core phiKMVviruses despite a sequence-based relationship to T7 and SP6-related phages. Crucially Andromeda9s genome has no less than 80 hypervariable sites (SNPs) which show genome wide distribution resulting in heterogenous populations of this phage reminiscent of those of RNA virus quasispecies.