title: Diversity of diazotrophic unicellular cyanobacteria in the tropical North Atlantic Ocean.
abstract: We present data on the genetic diversity and phylogenetic affinities of N2-fixing unicellular cyanobacteria in the plankton of the tropical North Atlantic Ocean. Our dinitrogenase gene (nifH) sequences grouped together with a group of cyanobacteria from the subtropical North Pacific; another subtropical North Pacific group was only distantly related. Most of the 16S ribosomal DNA sequences from our tropical North Atlantic samples were closely allied with sequences from a symbiont of the diatom Climacodium frauenfeldianum. These findings suggest a complex pattern of evolutionary and ecological divergence among unicellular cyanobacteria within and between ocean basins.
authors.affiliation: Marine Sciences Research Center, Stony Brook University, Stony Brook, New York 11794-5000, USA. lfalcon@sfsu.edu
authors.forename: Luisa I
authors.initials: LI
authors.lastname: Falcón
authors.forename: Frank
authors.initials: F
authors.lastname: Cipriano
authors.forename: Andrei Y
authors.initials: AY
authors.lastname: Chistoserdov
authors.forename: Edward J
authors.initials: EJ
authors.lastname: Carpenter
mesh_terms: D001267:Atlantic Ocean; D005075:Biological Evolution; D000458:Cyanobacteria / Q000145:classification / Q000235:genetics*; D004269:DNA, Bacterial / Q000032:analysis; D014644:Genetic Variation; D008386:Marine Biology; D010088:Oxidoreductases / Q000235:genetics*; D012336:RNA, Ribosomal, 16S / Q000235:genetics*; D014871:Water Microbiology
chemical_list: D004269:DNA, Bacterial; D012336:RNA, Ribosomal, 16S; D010088:Oxidoreductases; C029130:nitrogenase reductase