Phylogenetic and molecular clock inferences of cyanobacterial strains within Rivulariaceae from distant environments


Heterocyst-forming cyanobacteria are important players at both evolutionary and ecological scales, but to date it has been difficult to establish their phylogenetic affiliations. We present data from a phylogenetic and molecular clock analysis of heterocystous cyanobacteria within the family Rivulariaceae, including the genera Calothrix, Rivularia, Gloeotrichia and Tolypothrix. The strains were isolated from distant geographic regions including fresh and brackish water bodies, microbial mats from beach rock, microbialites, pebble beaches, plus PCC strains 7103 and 7504. Phylogenetic inferences (distance, likelihood and Bayesian) suggested the monophyly of genera Calothrix and Rivularia. Molecular clock estimates indicate that Calothrix and Rivularia originated $\sim$1500 million years ago (MYA) ago and species date back to 400-300MYA while Tolypothrix and Gloeotrichia are younger genera (600-400MYA). {\textcopyright} 2010 Federation of European Microbiological Societies Published by Blackwell Publishing Ltd. All rights reserved.

FEMS Microbiology Letters
Beatriz Díez Moreno
Beatriz Díez Moreno
Associate Professor.
P. Universidad Católica de Chile.
School of Biological Sciences,
Department of Molecular
Genetics and Microbiology,
Santiago, Chile.