title: Killer-sensitive coexistence in metapopulations of micro-organisms.
abstract: Many micro-organisms are known to produce efficient toxic substances against conspecifics and closely related species. The widespread coexistence of killer (toxin producer) and sensitive (non-producer) strains is a puzzle calling for a theoretical explanation. Based on stochastic cellular automaton simulations and the corresponding semi-analytical configuration-field approximation models, we suggest that metapopulation dynamics offers a plausible rationale for the maintenance of polymorphism in killer-sensitive systems. A slight trade-off between toxin production and population growth rate is sufficient to maintain the regional coexistence of toxic and sensitive strains, if toxic killing is a local phenomenon restricted to small habitat patches and local populations regularly go extinct and are renewed via recolonizations from neighbouring patches. Pattern formation on the regional scale does not play a decisive part in this mechanism, but the local manner of interactions is essential.
authors.affiliation: Theoretical Biology and Ecology Research Group, Hungarian Academy of Sciences and Eötvös University, Pázmány P. sétány 1/C, H-1117 Budapest, Hungary.
authors.forename: Tamás L
authors.initials: TL
authors.lastname: Czárán
authors.forename: Rolf F
authors.initials: RF
authors.lastname: Hoekstra
mesh_terms: D017753:Ecosystem; D055646:Killer Factors, Yeast; D008954:Models, Biological; D009183:Mycotoxins / Q000235:genetics / Q000378:metabolism*; D010641:Phenotype; D011110:Polymorphism, Genetic; D013997:Time Factors; D015003:Yeasts / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*
chemical_list: D055646:Killer Factors, Yeast; D009183:Mycotoxins