Schematic representation of W/Kit upstream region: (A) Restriction map of Kit upstream region. Sites for the restriction enzymes Not1 (N), EcoR1 (E), XbaI (X),SalI (S), MluI (M), ClaI (C ),PmeI (P), HindIII (H), AccI (A), Sac1 (Sc), BamH1 (B), PstI (Ps) are indicated. Sites for restriction enzymes determined for the entire region are shown without brackets. Sites for enzymes for which only a partial map exists are indicated with brackets. Scale in kilobases is shown. The relative position and size of overlapping P1 clones used to establish this restriction map is shown below. (B) Scheme used for the determination of the W^sh breakpoint. The relative position of probes used is indicated. A 0.9 kbHindIII-AccI fragment located at −72 kb was used to identify W^sh breakpoint. (C) Schematic of the identification of the W⁵⁷deletion endpoints located −34 to −38 kb and −146 to −147 kb upstream of the Kit transcription start site. The 0.6 kbBamH1-PstI and the 0.8 kb Xbal-Xhol probes used for the identification of the 5′ and the 3′, respectively, deletion endpoints are indicated.