Cckbr^tm1Tom

Part of exon 2 and exons 3-5 were replaced with a lacZ-PGK-neo cassette via homologous recombination resulting in deletion of the majority of 7 transmembrane regions after amino acid 108. Absence of gene expression was demonstrated by Northern blot analysis of cerebral cortex, basal ganglion, stomach, and pancreas mRNA from homozygous mutant animals using a 2.3 kb cDNA fragment as the probe. Absence of functional receptor protein was confirmed via binding assays using brain cell membrane preparations from homozygous mutants. (J:35876)