Revealing Toxin Signatures in Cyanobacteria: Report of Genes Involved in Cylindrospermopsin Synthesis from Saxitoxin-Producing Cylindrospermopsis raciborskii

摘要: Cyanotoxins are distinctive molecules in Cyanobacteria whose evolutionary origin, radiation and ecological role still controversial. The cyanobacterium Cylindrospermopsis raciborskii is alternately capable of producing two types potent toxins, cylindrospermopsin (CYN) or saxitoxin analogues (SAX). It has been proposed that this species spread to all continents early its history biogeographical differences toxin production found between populations. Most reports indicate American strains able produce SAX but not CYN, while Australian described CYN SAX. Here we describe the presence three genes belonging cluster (cyr), cyrA, cyrB cyrC, South C. strains, MVCC14 MVCC19, which due their morphology, growth preferences, genetic context defined as different ecotypes. No was detected either strain (by ELISA) after under nitrogen replete nitrogen-free nutrient conditions. Phylogenetic analyses cyrC partial sequences from both showed high similarity (>99%) with Australia Germany Aphanizomenon strains. This first report cyr known only