Diversity of viral photosystem-I psaA genes

• DOI: 10.1038/ismej.2014.244
• Publication Date: 2014-12-23T14:55:56Z
• Authors: Gur Hevroni; Hagay Enav; Forest Rohwer; Oded Béjà
• Keywords: Prochlorococcus; Horizontal Gene Transfer; Myoviridae

Abstract Marine photosynthesis is one of the major contributors to global carbon cycle and world’s oxygen supply. This process largely driven by cyanobacteria, namely Synechococcus Prochlorococcus. Genes encoding photosystem-II (PSII) reaction center proteins are found in many cyanophage genomes, expressed during infection their hosts. On basis metagenomics, photosystem-I (PSI) gene cassettes were recently discovered with two arrangements psaJF→C→A→B→K→E→D psaD→C→A→B. It was suggested that horizontal transfer PSII PSI genes increasing phage fitness. To better understand diversity, we designed degenerate primers cover a wide diversity organisms, using PCR targeted psaC→A arrangement, which unique cyanophages cassettes. We examined viral concentrates from four islands Pacific Ocean samples containing arrangement. Analyses amplified psaA revealed six subgroups varying level similarity %G+C content, suggesting greater than originally thought.