title: Components of selection in X chromosome lines of Drosophila melanogaster: sex ratio modification by meiotic drive and viability selection.
abstract: Selection coefficients and segregation parameters have been estimated in 18 randomly chosen lines carrying wild X chromosomes on the cn bw genetic background. Each line was studied in replicated crosses of four types, with approximately 100 replications per line per cross. Crosses in which male X chromosomes differed exhibited significant sex ratio heterogeneity. Maximum likelihood estimation of segregation parameters revealed two lines in which the proportion of X-bearing gametes produced by males was significantly different from Mendelian expectations. These observations suggest that segregation distortion is a common feature of naturally occurring genetic variation. Non-Mendelian segregation has important evolutionary implications.
mesh_terms: D000818:Animals; D004330:Drosophila / Q000235:genetics; D004331:Drosophila melanogaster / Q000235:genetics*; D005260:Female; D008297:Male; D008540:Meiosis; D012641:Selection, Genetic; D012744:Sex Ratio; D013045:Species Specificity