The genetics of a putative social trait in natural populations of yeast |
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Authors: | G. O. Bozdag D. Greig |
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Affiliation: | 1. Max Planck Institute for Evolutionary Biology, , Pl?n, 24306 Germany;2. The Galton Laboratory, Department of Genetics, Evolution, and Environment, University College London, , London, WC1E 6BT UK |
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Abstract: | The sharing of secreted invertase by yeast cells is a well‐established laboratory model for cooperation, but the only evidence that such cooperation occurs in nature is that the SUC loci, which encode invertase, vary in number and functionality. Genotypes that do not produce invertase can act as ‘cheats’ in laboratory experiments, growing on the glucose that is released when invertase producers, or ‘cooperators’, digest sucrose. However, genetic variation for invertase production might instead be explained by adaptation of different populations to different local availabilities of sucrose, the substrate for invertase. Here we find that 110 wild yeast strains isolated from natural habitats, and all contained a single SUC locus and produced invertase; none were ‘cheats’. The only genetic variants we found were three strains isolated instead from sucrose‐rich nectar, which produced higher levels of invertase from three additional SUC loci at their subtelomeres. We argue that the pattern of SUC gene variation is better explained by local adaptation than by social conflict. |
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Keywords: | cheating cooperation copy number variation droplet digital PCR
Saccharomyces
SUC
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