PCR-restriction fragment length polymorphism analysis of Iy^a-phenotyped individuals with use ofNarI.

(A) A 332-base-pair product encompassing nucleotides 47-378 of theGPIbβ gene was obtained from genomic DNA by using primers GPIbβ 1 and GP Ibβ 3. The arrows indicate the cleavage sites recognized by the restriction endonuclease NarI. The length of the expected digested fragments from Iy^a-positive and Iy^a-negative alleles is also shown. (B) Analysis ofNarI-digested PCR products from genomic DNA of the members of the Iy family (left panel) and the Kr family (right panel). Lanes are inscribed according to the pedigrees (Figure 4). Undigested products from samples obtained from 3 individuals are shown in lanes 1 to 3 (left panel). In lane M, pBr 322 HaeIII DNA fragments are shown as standards.