title: Size and competitive mating success in the yeastSaccharomyces cerevisiae.
abstract: In unicellular organisms like yeast, mating with the right partner is critical to future fitness because each individual can only mate once. Because cell size is important for viability, mating with a partner of the right size could be a significant advantage. To investigate this idea, we manipulated the size of unmated yeast cells and showed that their viability depended on environmental conditions; large cells do better on rich medium and small cells do better on poor medium. We also found that the fitness of offspring is determined by the size of their parents. Finally, we demonstrated that when a focal cell of one mating type was placed with a large and a small cell of the opposite mating type, it was more likely to mate with the cell that was closer to the optimum size for growth in a given environment. This pattern was not generated by differences in passive mating efficiency of large and small cells across environments but by competitive mating behavior, mate preference, or both. We conclude that the most likely mechanism underlying this interesting behavior is that yeast cells compete for mates by producing pheromone signals advertising their viability, and cells with the opportunity to choose prefer to mate with stronger signalers because such matings produce more viable offspring.
authors.affiliation: The Galton Laboratory, Department of Genetics, Evolution, and Environment, University College London , Gower Street , London WC1E 6BT , UK .
authors.forename: Carl
authors.initials: C
authors.lastname: Smith
authors.affiliation: The Galton Laboratory, Department of Genetics, Evolution, and Environment, University College London , Gower Street , London WC1E 6BT , UK , ; CoMPLEX, University College London , Gower Street , London WC1E 6BT , UK , and.
authors.forename: Andrew
authors.initials: A
authors.lastname: Pomiankowski
authors.affiliation: The Galton Laboratory, Department of Genetics, Evolution, and Environment, University College London , Gower Street , London WC1E 6BT , UK , ; Max Planck Institute for Evolutionary Biology , August Thienemann Strasse 2 , Plön 24306 , Germany.
authors.forename: Duncan
authors.initials: D
authors.lastname: Greig
keywords: Saccharomyces cerevisiae; body size; cell size; mate choice; mating; sexual selection.