SEVERE PHENOTYPE IN MICE WITH TERMINATION MUTATION IN EXON-2 OF CYSTIC-FIBROSIS GENE

Mice with a termination codon mutation in exon 2 of the cystic fibrosi s (CF) gene were generated rising homologous recombination in embryoni c stem cells. Animals homozygous for the mutant allele display a sever e intestinal phenotype similar to that previously reported for CF muta nt mice. The null nature of this allele was demonstrated by the absenc e of detectable wild-type mRNA, by the absence of detectable CFTR in t he serous gland collecting ducts of salivary tissues, and by the lack of cAMP-mediated short-circuit current responses in colonic epithelium of mutant animals.