A genomic fragment (8.4 kb) covering exons 10-12 was replaced with a 1.9-kb phosphoglycerate kinase-neomycin resistance (PGK-Neo) cassette. This mutation causes an reading frame shift and thereby generates a loss-of-function allele. Semi-quantitative RT-PCR and immunofluorescence staining confirmed absence of expression in the intestine of homozygous mutant mice. (J:243849)