Gucy1a1^tm1.1Brou

Exon 6 of Gucy1a3 gene which codes for a conserved portion of the catalytic domain was flanked by a loxP and a loxP-neo-loxP cassette. The exon 6 and neo cassette was removed in ES cells by transient cre expression leaving a single loxP in place. Northern blot and RT-PCR confirmed excision of exon 6 in the transcript; however, immunoblot revealed a smaller mutant 59-kDa protein in homozygous mice. Mutant protein was determined to be inactive, thus it is functional null allele. (J:151161)