title: Meiotic sex ratio variation in natural populations of Ceratodon purpureus (Ditrichaceae).
abstract: •
  
  
  OBJECTIVE
  Sex ratio variation is a common but often unexplained phenomenon in species across the tree of life. Here we evaluate the hypothesis that meiotic sex ratio variation can contribute to the biased sex ratios found in natural populations of the moss Ceratodon purpureus.•
  
  
  METHODS
  We obtained sporophytes from several populations of C. purpureus from eastern North America. From each sporophyte, we estimated the mean spore viability by germinating replicate samples on agar plates. We estimated the meiotic sex ratio of each sporophyte by inferring the sex of a random sample of germinated spores (mean = 77) using a PCR-RFLP test. We tested for among-sporophyte variation in viability using an ANOVA and for deviations from 1:1 sex ratio using a χ(2)-test and evaluated the relationship between these quantities using a linear regression.•
  
  
  RESULTS
  We found among-sporophyte variation in spore viability and meiotic sex ratio, suggesting that genetic variants that contribute to variation in both of these traits segregate within populations of this species. However, we found no relationship between these quantities, suggesting that factors other than sex ratio distorters contribute to variation in spore viability within populations.•
  
  
  CONCLUSIONS
  These results demonstrate that sex ratio distortion may partially explain the population sex ratio variation seen in C. purpureus, but more generally that genetic conflict over meiotic segregation may contribute to fitness variation in this species. Overall, this study lays the groundwork for future studies on the genetic basis of meiotic sex ratio variation.
authors.affiliation: Department of Biology, University of Florida, Gainesville, Florida 32611-8525 USA.
authors.forename: Tatum E
authors.initials: TE
authors.lastname: Norrell
authors.affiliation: Department of Biology, University of Florida, Gainesville, Florida 32611-8525 USA.
authors.forename: Kelly S
authors.initials: KS
authors.lastname: Jones
authors.affiliation: Department of Biology, University of Florida, Gainesville, Florida 32611-8525 USA.
authors.forename: Adam C
authors.initials: AC
authors.lastname: Payton
authors.affiliation: Department of Biology, University of Florida, Gainesville, Florida 32611-8525 USA.
authors.forename: Stuart F
authors.initials: SF
authors.lastname: McDaniel
mesh_terms: D019068:Bryopsida / Q000235:genetics*; D019143:Evolution, Molecular; D056084:Genetic Fitness; D014644:Genetic Variation; D008540:Meiosis; D012098:Reproduction; D012744:Sex Ratio; D013170:Spores
keywords: Ceratodon purpureus; Dirichaceae; bryophyte; meiotic sex ratio; segregation distortion; sex chromosome