Low genomic diversity in tropical oceanic N2-fixing cyanobacteria

@article{citeulike:1867472, abstract = {High levels of genomic and allelic microvariation have been found in major marine planktonic microbial species, including the ubiquitous open ocean cyanobacterium,Prochlorococcus marinus. Crocosphaera watsonii is a unicellular cyanobacterium that has recently been shown to be important in oceanic N2 fixation and has been reported from the Atlantic and Pacific oceans in both hemispheres, and the Arabian Sea. In direct contrast to the current observations of genomic variability in marine non-N2-fixing planktonic cyanobacteria, which can range up to >15\% nucleotide sequence divergence, we discovered that the marine planktonic nitrogen-fixing cyanobacterial genus Crocosphaera has remarkably low genomic diversity, with <1\% nucleotide sequence divergence in several genes among widely distributed populations and strains. The cultivated C. watsonii WH8501 genome sequence was virtually identical to DNA sequences of large metagenomic fragments cloned from the subtropical North Pacific Ocean with <1\% sequence divergence even in intergenic regions. Thus, there appears to be multiple strategies for evolution, adaptation, and diversification in oceanic microbial populations. The C. watsonii genome contains multiple copies of several families of transposases that may be involved in maintaining genetic diversity through genome rearrangements. Although genomic diversity seems to be the rule in many, if not most, marine microbial lineages, different forces may control the evolution and diversification in low abundance microorganisms, such as the nitrogen-fixing cyanobacteria. 10.1073/pnas.0701017104}, author = {Zehr, Jonathan P. and Bench, Shellie R. and Mondragon, Elizabeth A. and Mccarren, Jay and Delong, Edward F. }, citeulike-article-id = {1867472}, doi = {http://dx.doi.org/10.1073/pnas.0701017104}, journal = {Proceedings of the National Academy of Sciences}, keywords = {marine-microbiology, microbial-diversity, microbial-species, population-genetics, recombination}, month = {October}, pages = {0701017104+}, posted-at = {2007-11-05 13:05:06}, priority = {2}, title = {Low genomic diversity in tropical oceanic N2-fixing cyanobacteria}, url = {http://dx.doi.org/10.1073/pnas.0701017104}, year = {2007} }

TY - JOUR ID - citeulike:1867472 L3 - citeulike-article-id:1867472 TI - Low genomic diversity in tropical oceanic N2-fixing cyanobacteria JF - Proceedings of the National Academy of Sciences SP - 0701017104 N2 - High levels of genomic and allelic microvariation have been found in major marine planktonic microbial species, including the ubiquitous open ocean cyanobacterium,Prochlorococcus marinus. Crocosphaera watsonii is a unicellular cyanobacterium that has recently been shown to be important in oceanic N2 fixation and has been reported from the Atlantic and Pacific oceans in both hemispheres, and the Arabian Sea. In direct contrast to the current observations of genomic variability in marine non-N2-fixing planktonic cyanobacteria, which can range up to >15% nucleotide sequence divergence, we discovered that the marine planktonic nitrogen-fixing cyanobacterial genus Crocosphaera has remarkably low genomic diversity, with <1% nucleotide sequence divergence in several genes among widely distributed populations and strains. The cultivated C. watsonii WH8501 genome sequence was virtually identical to DNA sequences of large metagenomic fragments cloned from the subtropical North Pacific Ocean with <1% sequence divergence even in intergenic regions. Thus, there appears to be multiple strategies for evolution, adaptation, and diversification in oceanic microbial populations. The C. watsonii genome contains multiple copies of several families of transposases that may be involved in maintaining genetic diversity through genome rearrangements. Although genomic diversity seems to be the rule in many, if not most, marine microbial lineages, different forces may control the evolution and diversification in low abundance microorganisms, such as the nitrogen-fixing cyanobacteria. 10.1073/pnas.0701017104 KW - marine-microbiology KW - microbial-diversity KW - microbial-species KW - population-genetics KW - recombination AU - Zehr, Jonathan AU - Bench, Shellie AU - Mondragon, Elizabeth AU - Mccarren, Jay AU - Delong, Edward PY - 2007/10/30/ UR - http://dx.doi.org/10.1073/pnas.0701017104 ER -