Role of interference competition in the maintenance of diversity in yeast Saccharomyces cerevisiae.
Dominika M. Wloch-Salamon, J. Arjan G. M de Visser, Rolf F. Hoekstra
Laboratory of Genetics, WAGENINGEN UNIVERSITY, Arboretumlaan 4, Wageningen, 6703 BD, Netherlands
Identifying the mechanisms that lead to the origin and maintenance of biodiversity is an important goal in ecology and evolutionary biology. Theoretical models and evidence from empirical studies using bacteria show that interference competition (e.g. via the production of anti-competitor toxins), especially in structured environments, may be crucial for long lasting coexistence of competing species. We test those predictions empirically using three diploid baker yeast strains of known non-transitive hierarchical competitiveness (killer K1, resistant to killer RK1, and sensitive to killer SK1) by competing them in unstructured (continuously shaking, liquid) and structured (agar plates) environments. We demonstrate that the ability of the toxin producer to invade a population of sensitives depends on the structure of the environment. These results will be used in future experiments where we study the role of interference competition using 3 different toxin producers in the long-term maintenance of diversity.