Allelic expression of p73. Differential expression was detected by NlaIII digestion of RT-PCR products. The large arrow indicates the uncut band (390 bp). The small arrow (a) indicates the 358-bp product (NlaIII cuts at codon 223) when codon 349 is CAC (not cut with NlaIII). The small arrows (b) and (c) indicate the 277-bp and 89-bp bands, respectively, afterNlaIII cuts at both codon 349 (CAT) and codon 223. C, cut withNlaIII; U, uncut.