GENETIC-MAP OF THE FUSED LOCUS ON MOUSE CHROMOSOME-17

Fused (Fu) is a dominant mutation in mice resulting in the asymmetry and fusion of tail vertebrae in heterozygotes. Fu/Fu homozygotes are often viable and can exhibit a duplication of the terminal tail vertebrae resulting in bifurcated tails. There are two more severe alleles at Fu, Kinky (Fu(Ki)) and Knobbly (Fu(Kb)), which die between 9 and 10 days of gestation as homozygotes, exhibiting a duplication of the embryonic axis, leading to incomplete or complete twinning. To define the precise map position of the Fu(Ki) mutation on mouse Chromosome 17, a 983-animal (Fu(Ki) tf x Mus spretus)F-1, X + tf/ + tf interspecific backcross was generated and scored for Fu(Ki), another tightly linked visible marker tufted (tf), and five linked molecular loci, D17MIT18, D17Leh54, D17Aus57, Hba-ps4, and Pim1. The order and genetic distances between the markers were determined to be centromere-D17MIT18-5.79 cM-D17Leh54-0.85 cM-D17Pri6-0.12 cM-D17Pri7-0.12 cM-Hba-ps4-1.20 cM-D17Pri8-0.48 cM-tf-2.05 cM-Pim1. The Fu(Ki) gene could not be genetically separated from three molecular markers, D17Pri6, D17Pri7, and Hba-ps4. Yeast artificial chromosome clones that contain these tightly linked markers have been isolated to form a contig that contains Fu(Ki). Recombination breakpoints generated through the interspecies backcross were mapped onto the contig and demonstrate that recombination in this region is not random. (C) 1994 Academic Press, Inc.