EXCLUSION OF SOX9 AS A CANDIDATE FOR THE MOUSE MUTANT TAIL-SHORT

The Sry-related gene Sox9 has been proposed as the gene responsible fo r the mouse skeletal mutant Tail-short (Ts), on the basis of its expre ssion in skeletogenic mesenchymal condensations in the mouse embryo an d its chromosomal location in the region of Ts on distal Chromosome (C hr) 11. We present here detailed mapping of Ts locus relative to the S ox9, using an inter-subspecific cross. Among 521 backcross progeny, 16 recombinants were detected between Sox9 and Ts, suggesting a separati on of 3.5 +/- 0.01 cM, and excluding Sox9 as a candidate for Ts. A fur ther nine recombinants were detected between Ts and the poly-comb-like gene M33, suggesting that these loci are separated by 1.8 +/- 0.011 c M. Six microsatellite markers were co-localized to the Ts locus, provi ding reagents for positional cloning of Ts.