title: Phylogenetic and molecular clock inferences of cyanobacterial strains within Rivulariaceae from distant environments.
abstract: 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 ∼1500 million years ago (MYA) ago and species date back to 400-300 MYA while Tolypothrix and Gloeotrichia are younger genera (600-400 MYA).
authors.affiliation: Instituto de Ecología, UNAM, Ciudad Universitaria, Coyoacán México DF, México.
authors.forename: Julia
authors.initials: J
authors.lastname: Domínguez-Escobar
authors.forename: Yislem
authors.initials: Y
authors.lastname: Beltrán
authors.forename: Birgitta
authors.initials: B
authors.lastname: Bergman
authors.forename: Beatriz
authors.initials: B
authors.lastname: Díez
authors.forename: Karolina
authors.initials: K
authors.lastname: Ininbergs
authors.forename: Valeria
authors.initials: V
authors.lastname: Souza
authors.forename: Luisa I
authors.initials: LI
authors.lastname: Falcón
mesh_terms: D000458:Cyanobacteria / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification*; D004783:Environmental Microbiology; D019143:Evolution, Molecular; D008969:Molecular Sequence Data; D010802:Phylogeny