Fig. 1.

Determination of codon 72 polymorphisms by restriction endonuclease digests. PCR products of exon 4 were digested either with BsaJI (lane 1–3) or with BstUI (lane 4–6); undigested DNA (lane 7) and a 50-bp marker (lane 8). The samples were homozygously Pro/Pro (lane 1 and 4), heterozygously Arg/Pro (lane 2 and 5) and homozygously Arg/Arg (lane 3 and 6). In the heterozygous condition, note the somewhat weaker expression of bands (i.e. lane 2, bands at 94 bp and 44 bp; lane 5, band at 127 bp.