Centromere‐associated meiotic drive and female fitness variation in Mimulus. (8th May 2015)

• Record Type: Journal Article
• Authors: Fishman, Lila; Kelly, John K.
• Is Part Of: Evolution. Volume 69:Number 5(2015:May)
• Page Start: 1208
• Page End: 1218
• Publication Date: 2015-05-08
• Subjects: Balancing selection -- centromere -- genetic conflict -- polymorphism -- seedset -- selfish genetic element -- standing variation; Evolution -- Periodicals; Heredity -- Periodicals; Évolution (Biologie) -- Périodiques; Hérédité -- Périodiques; 338.47004094
• DOI: 10.1111/evo.12661
• Languages: English
• ISSNs: 0014-3820

Abstract

Abstract : Female meiotic drive, in which chromosomal variants preferentially segregate to the egg pole during asymmetric female meiosis, is a theoretically pervasive but still mysterious form of selfish evolution. Like other selfish genetic elements, driving chromosomes may be maintained as balanced polymorphisms by pleiotropic or linked fitness costs. A centromere‐associated driver ( D ) with a ∼58:42 female‐specific transmission advantage occurs at intermediate frequency (32–40%) in the Iron Mountain population of the yellow monkeyflower, Mimulus guttatus . Previously determined male fertility costs are sufficient to prevent the fixation of D, but predict a higher equilibrium frequency. To better understand the dynamics and effects of D, we developed a new population genetic model and measured genotype‐specific lifetime female fitness in the wild. In three of four years, and across all years, D imposed significant recessive seedset costs, most likely due to hitchhiking by deleterious mutations. With both male and female costs as measured, and 58:42 drive, our model predicts an equilibrium frequency of D (38%) very close to the observed value. Thus, D represents a rare selfish genetic element whose local population genetic dynamics have been fully parameterized, and the observation of equilibrium sets the stage for investigations of coevolution with suppressors.