Physical maps of the wly mutation on mouse Chr 11. (a) Molecular markers and genes on mouse Chr 11 that are linked with wly. Markers in grey (D11Mit313 and D11Mit261) have been reported by others to flank the wly mutation . Segregation data from the large, 1,679-member backcross (shown in Figure 2) place wly between the markers shown in blue (D11Mit208 and D11Mit242). Single-nucleotide polymorphisms (SNP1-6, see Additional file 1 & Additional file 2) were used to further localize crossovers among those backcross mice recombinant between D11Mit208 and D11Mit242 (the numbers of crossovers located in each interval are shown below the chromosome). Three such recombinants located wly between SNP2 and SNP6 (shown in red). A 1-Mb scale bar is shown below the linear arrangement of these markers. An expanded physical map of the markers and genes (represented by colored rectangles) located between SNP2 and SNP6 is shown below the chromosome and above a 0.1 Mb scale bar. Markers shown in green were never separated from wly in the backcross panel. Mice homozygous for null-alleles of the genes shown in blue have normal furry coats, making these genes poor candidates for being the genetic basis of wly. For genes shown in orange, available expression and functional data [3, 4] did not overtly implicate skin, but genes shown in yellow are known to be expressed in mouse skin. (b) The Fam83g gene has been expanded (note the .01 Mb scale bar) to show the arrangement of its five exons. Taller green boxes represent coding regions, and shorter white boxes represent untranslated regions. The portion of Intron 2–3 and Exon 3 boxed in red on the wild type allele is deleted in mutant mice (see also Figure 4a). This disruption is predicted to alter mRNA splicing of the mutant Fam83g transcript, as indicated.