Transmission ratio distortion in mouse t-haplotypes is due to multiple distorter genes acting on a responder locus.
Transmission ratios of male mice heterozygous for various combinations of partial t-haplotypes provide evidence in support of a model for the genetic basis of ratio distortion, involving two or more distorter genes acting on a responder locus. The t form of the responder locus, Tcr, in the medial part of the haplotype, must be present and heterozygous for distortion to occur. When the responder alone is present, as in t low haplotypes, the chromosome carrying it is transmitted in a low ratio (less than 50%). The t forms of the distorter loci act additively, in cis or trans, to raise the transmission of whichever chromosome carries Tcr. Identified distorter loci are Tcd-1, in the proximal part of the haplotype, Tcd-2, distal to Tcr, and probably Tcd-3, lying between Tcr and Tcd-2. In the absence of Tcr the distorters are transmitted normally. The system is compared with the SD system of Drosophila.
D000483:Alleles; D000818:Animals; D003433:Crosses, Genetic; D004330:Drosophila / Q000235:genetics; D005260:Female; D005796:Genes; D005804:Genes, Lethal; D008040:Genetic Linkage; D006238:Haploidy; D006579:Heterozygote; D006720:Homozygote; D006801:Humans; D008957:Models, Genetic