A part of exon 8 encoding amino acids 360-390 was replaced with a neomycin selection cassette. Northern blot analysis demonstrated that no detectable full length transcript was produced from this allele in stomach of homozygous mice, although trace levels of a shorter 1 kb transcript was detected. Immunocytochemistry experiments on stomach tissue of homozygous mice demonstrated that no detectable protein was present. (J:63470)