Identification of a KIT transcript lacking exon 17 in pigs with the dominant white allele. Agarose gel electrophoresis of RT–PCR products of KIT exon 16–19. Samples 1–3 and 4–6 are Swedish Large White (homozygous or heterozygous for the I allele) and Swedish Hampshire (i/i) pigs, respectively. The size difference between the 424- and 301-bp fragments is due to the lack of exon 17 in the latter fragment. The two upper bands of samples 1–3 were shown to be heteroduplexes (HDs) formed between the normal and splice mutant form. The tendency for different relative amounts of the 424- and 301-bp fragments may be a PCR artifact but may also have a biological cause, e.g., whether an animal is heterozygous or homozygous for the I allele.