A factor on a wild third chromosome (IIIRa) that modifies the segregation distortion phenomenon in Drosophila melanogaster.
D000818:Animals; D002874:Chromosome Mapping; D002875:Chromosomes; D004331:Drosophila melanogaster; D005260:Female; D005787:Gene Frequency; D005796:Genes; D008297:Male; D008540:Meiosis; D010641:Phenotype; D012737:Sex Factors