|
|
||||||||
International Journal of Systematic and Evolutionary Microbiology, Vol 52, 861-867, Copyright © 2002 by Society for General Microbiology
J. F. Manen and J. Falquet
University of Geneva, Conservatoire et Jardin Botaniques, Imperatrice 1, CH-1292 Chambesy, Switzerland
To investigate the genetic diversity of the genus Arthrospira and to compare it with other cyanobacteria, sequences of 670 nt from the phycocyanin operon were determined for 23 natural, cultivated or commercial strains of Arthrospira and compared with sequences from 20 other non-Arthrospira cyanobacterial strains. The sequenced DNA fragment comprises the last 255 nt of cpcB, the cpcB--cpcA spacer and the first 304 nt of cpcA. The resulting phylogenetic tree confirms that the genus Arthrospira is not related to Spirulina. So far, cpcB--cpcA data suggest that the closest relative of Arthrospira is Planktothrix. Based on this locus, the genus Arthrospira consists of three genetically clustered lineages. However, the distribution of nucleotide substitutions indicates that these three lineages are not the result of a simple cladogenesis characterized by the accumulation of independent substitutions. Instead, the observed clustering is the result of horizontal transfers of blocks of sequences. Analysis of the distribution of substitutions in the sequenced fragment indicates a point of intragenic recombination close to the stop codon of cpcB. The capacity of exchange of genetic material among strains probably explains why morphology and geographical origin do not correlate with the cpcB--cpcA clusters. Nevertheless, this study shows for the first time that the genus Arthrospira, represented here by cultivated and wild specimens, is clearly monophyletic. Moreover, the cpcB--cpcA DNA fragment, comprising both highly and moderately variable regions, allows (1) a strict differentiation of the taxon Arthrospira from other cyanobacteria (using the coding regions only) and (2) the study of relationships inside Arthrospira (using both the coding and non-coding regions).
This article has been cited by other articles:
![]() |
A. Stuken, R. J. Campbell, A. Quesada, A. Sukenik, P. K. Dadheech, and C. Wiedner Genetic and morphologic characterization of four putative cylindrospermopsin producing species of the cyanobacterial genera Anabaena and Aphanizomenon J. Plankton Res., May 1, 2009; 31(5): 465 - 480. [Abstract] [Full Text] [PDF] |
||||
![]() |
E. Berrendero, E. Perona, and P. Mateo Genetic and morphological characterization of Rivularia and Calothrix (Nostocales, Cyanobacteria) from running water Int J Syst Evol Microbiol, February 1, 2008; 58(2): 447 - 460. [Abstract] [Full Text] [PDF] |
||||
![]() |
R. W. Thacker and V. J. Paul Morphological, Chemical, and Genetic Diversity of Tropical Marine Cyanobacteria Lyngbya spp. and Symploca spp. (Oscillatoriales) Appl. Envir. Microbiol., June 1, 2004; 70(6): 3305 - 3312. [Abstract] [Full Text] [PDF] |
||||
![]() |
N. D. Crosbie, M. Pockl, and T. Weisse Dispersal and Phylogenetic Diversity of Nonmarine Picocyanobacteria, Inferred from 16S rRNA Gene and cpcBA-Intergenic Spacer Sequence Analyses Appl. Envir. Microbiol., September 1, 2003; 69(9): 5716 - 5721. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| INT J SYST EVOL MICROBIOL | MICROBIOLOGY | J GEN VIROL |
| J MED MICROBIOL | ALL SGM JOURNALS | |