Fig. 2. Positional cloning of the sly and gup loci. (A) Meiotic map of the sly locus (including the nearest polymorphic CA repeat marker Z11023) compared with the chromosome walk undertaken. Starting from elra (PAC 196M22), the walk proceeded from left to right in a series of YACs, represented by labelled, coloured bars, e.g. 177C8. Polymorphisms were identified from YAC ends at various points and used to ascertain the distance and direction to the sly locus. These markers are indicated on the meiotic map, e.g. 177T3. Sequence of lamininC1 exon 3 was found at the end of YAC 148F11. (B) Zebrafish laminin 
1 protein. The positions of the premature stop codons caused by mutation in the slym466 and slym86 alleles are indicated. Protein domains are indicated by colored shapes: red, putative signal peptide; blue hexagon, laminin N-terminal globular domain; purple pentagons, laminin-type EGF-like repeats; orange octagon, laminin B globular domain; green rectangles, coiled-coil domains. (C) Meiotic map surrounding the gup locus compared with the physical map generated using RH analysis. A polymorphic marker, cat/gca, was identified by AFLP analysis and was found to map to LG25. Two candidates genes, lamb4 and lamb1, were established to be closely linked. (D) Zebrafish laminin ß1 protein. The position of the premature stop codon caused by the mutation in the gupm189 allele is indicated. Protein domains are represented as in B above.
