Why Cyanobacteria Produce Toxins? Evolutionary Game Theory Suggests the Key

• Published in: International journal of biology 2015-01, Vol.7 (1), p.64-64
• Main Authors: Baselga-Cervera, Beatriz, Garcia-Balboa, Camino, Costas, Eduardo, Lopez-Rodas, Victoria
• Format: Article
• Language: English
• Subjects: Cyanobacteria; Microcystis
• ISSN: 1916-9671; 1916-968X

Cyanobacteria are a source of potent toxins among which the microcystin (a hepatotoxic peptide encoded by the mcy gene cluster of Microcystis spp.) is a frequent cause of poisoning in inland waters worldwide. Although the molecular basis of microcystin production is known, its role is still unknown. It was suggested that microcystin production have a metabolic cost that could be offset by some benefit (e.g. protection from grazing). The authors check that microcystin-producing and non-producing strains occurs simultaneously in the Microcystis spp. blooms, evolutionary forces (mutation, genetic drift) control frequencies of microcystin production and non-production strains, and microcystin producing strains have diminished fitness compared with non-producing strains. The have employed evolutionary game theory to explain the maintaining of microcystin-producing genotypes in natural populations of Microcystis spp. A two-strategy (to produce or not microcystin), two-players game of cooperators (microcystin-producing genotypes) and cheaters (non-producing genotypes) explains the coexistence of both genotypes in the same bloom.