title: Molecular phylogeny, population genetics, and evolution of heterocystous cyanobacteria using nifH gene sequences.
abstract: In order to assess phylogeny, population genetics, and approximation of future course of cyanobacterial evolution based on nifH gene sequences, 41 heterocystous cyanobacterial strains collected from all over India have been used in the present study. NifH gene sequence analysis data confirm that the heterocystous cyanobacteria are monophyletic while the stigonematales show polyphyletic origin with grave intermixing. Further, analysis of nifH gene sequence data using intricate mathematical extrapolations revealed that the nucleotide diversity and recombination frequency is much greater in Nostocales than the Stigonematales. Similarly, DNA divergence studies showed significant values of divergence with greater gene conversion tracts in the unbranched (Nostocales) than the branched (Stigonematales) strains. Our data strongly support the origin of true branching cyanobacterial strains from the unbranched strains.
authors.affiliation: Laboratory of Microbial Genetics, Department of Botany, Banaras Hindu University, Varanasi, 221005, India.
authors.forename: Prashant
authors.initials: P
authors.lastname: Singh
authors.forename: Satya Shila
authors.initials: SS
authors.lastname: Singh
authors.forename: Josef
authors.initials: J
authors.lastname: Elster
authors.forename: Arun Kumar
authors.initials: AK
authors.lastname: Mishra
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics*; D000458:Cyanobacteria / Q000201:enzymology / Q000235:genetics*; D019143:Evolution, Molecular; D014644:Genetic Variation; D005828:Genetics, Population; D016680:Genome, Bacterial; D058977:Molecular Sequence Annotation; D010088:Oxidoreductases / Q000235:genetics*; D010802:Phylogeny; D017422:Sequence Analysis, DNA
chemical_list: D001426:Bacterial Proteins; D010088:Oxidoreductases; C029130:nitrogenase reductase