Aquatic Sciences Meeting, Albuquerque 2001

SS14 Microbial Diversity (Disciplinary Connections)

Date: Monday, February 12, 2001, Time: 2:30:00 PM

Location: Brazos

Dyble, J, , University of North Carolina at Chapel Hill, Morehead City, USA, dyble@email.unc.edu

Neilan, B, A, University of New South Wales, Sydney, Australia, b.neilan@unsw.edu.au

Paerl, H, W, University of North Carolina at Chapel Hill, Morehead City, USA, hpaerl@email.unc.edu

MOLECULAR CHARACTERIZATION OF GLOBAL GEOGRAPHIC VARIATION IN CYLINDROSPERMOPSIS RACIBORSKII USING NIFH AND CPCBA-IGS

Blooms of the diazotrophic cyanobacteria Cylindrospermopsis raciborskii are receiving increasing attention worldwide as they invade eutrophying freshwater sources used for recreation and drinking water supplies. Many C. raciborskii strains produce the heptatoxin cylindrospermopsin that is a threat to both animal and human health. To contribute to the characterization of the global population of C. raciborskii, the genetic variation within two environmentally relevant genes was investigated. NifH is a highly conserved gene involved in nitrogen fixation and cpcBA-IGS is part of the phycocyanin operon that gives cyanobacteria their characteristic blue-green color. Nucleotide sequences for each of these genes were obtained from C. raciborskii cultures from Europe (Germany, Hungary, Portugal), Australia (Queensland, New South Wales), and the Americas (Brazil, Florida, North Carolina). In phylogenies based upon the nifH and cpcBA-IGS sequences, the American strains clustered in a group separate from the rest of the strains and nifH sequences further differentiated the Australian and European C. raciborskii strains. Primers specific to the genus and to the American strains were designed. The geographic distribution of C. raciborskii was reflected in genetic variation among strains.

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Aquatic Sciences Meeting, Albuquerque 2001

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