title: Potential photosynthesis gene recombination between Prochlorococcus and Synechococcus via viral intermediates.
abstract: Genes (psbA and psbD) encoding for photosynthetically important proteins were recently found in a number of cultured cyanophage genomes. This phenomenon may be a beneficial trait to the viruses or their photosynthetic cyanobacterial hosts, or may represent an untapped pool of genes involved in the formation of the photosynthetic apparatus that are prone to lateral gene transfer. Here we show analyses of psbA genes from uncultured environmental viruses and prophage populations. We observe a statistically significant separation between viral genes and their potential Synechococcus hosts' genes, and statistical analyses under models of codon evolution indicate that the psbA genes of viruses are evolving under levels of purifying selection that are virtually indistinguishable from their hosts. Furthermore, our data also indicate the possible exchange and reshuffling of psbA genes between Synechococcus and Prochlorococcus via phage intermediates. Overall, these observations raise the possibility that marine viruses serve as a potential genetic pool in shaping the evolution of cyanobacterial photosynthesis.
authors.affiliation: Biology Sciences Faculties, Technion -- Israel Institute of Technology, Haifa 32000, Israel.
authors.forename: Gil
authors.initials: G
authors.lastname: Zeidner
authors.forename: Joseph P
authors.initials: JP
authors.lastname: Bielawski
authors.forename: Michael
authors.initials: M
authors.lastname: Shmoish
authors.forename: David J
authors.initials: DJ
authors.lastname: Scanlan
authors.forename: Gazalah
authors.initials: G
authors.lastname: Sabehi
authors.forename: Oded
authors.initials: O
authors.lastname: Béjà
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics; D001435:Bacteriophages / Q000235:genetics / Q000502:physiology; D019143:Evolution, Molecular; D010788:Photosynthesis / Q000235:genetics; D045332:Photosystem II Protein Complex / Q000235:genetics*; D010802:Phylogeny; D048929:Prochlorococcus / Q000235:genetics / Q000378:metabolism / Q000821:virology*; D039002:Prophages / Q000235:genetics; D011995:Recombination, Genetic; D012623:Seawater / Q000821:virology; D046940:Synechococcus / Q000235:genetics / Q000378:metabolism / Q000821:virology*
chemical_list: D001426:Bacterial Proteins; D045332:Photosystem II Protein Complex; C422369:photosystem II, psbA subunit; C085993:psbDI protein, cyanobacteria