Mutational effects depend on ploidy level: all else is not equal.
Ploidy is predicted to influence adaptation directly, yet whether single mutations behave the same in different ploidy backgrounds has not been well studied. It has often been assumed theoretically that aside from dominance, selective parameters do not differ between cells of varying ploidy. Using the budding yeast Saccharomyces cerevisiae, I compared the effect size of 20 adaptive mutations in haploids and homozygous diploids and found, surprisingly, that the same mutations often had a much larger effect in haploids than homozygous diploids. This empirical result demonstrates that it cannot be assumed that mutations will have the same effect in haploids and homozygous diploids.
Department of Zoology and Biodiversity Research Center, University of British Columbia, Vancouver, British Columbia, Canada. gerstein@zoology.ubc.ca
Aleeza C
AC
Gerstein
D000935:Antifungal Agents / Q000494:pharmacology*; D004171:Diploidy; D004305:Dose-Response Relationship, Drug; D025141:Drug Resistance, Fungal; D056084:Genetic Fitness; D006238:Haploidy; D006720:Homozygote; D009154:Mutation; D009761:Nystatin / Q000494:pharmacology*; D012441:Saccharomyces cerevisiae / Q000187:drug effects / Q000235:genetics*
D000935:Antifungal Agents; D009761:Nystatin