Bpnt2^tm1.2Aros

Two versions of exon2, a wild-type and an inverted mutated exon 2 with a G to A transition at position 726 leading to an asparagine substitution for the aspartate at amino acid 175 were introduced in a head-to-head orientation which were flanked by the head-to-head lox71 and loxKR3 sites and separated by an frt-flanked neomycin cassette. This mutation corresponds to the p.Asp177>Asn mutation detected in a patient with chondrodysplasia with joint dislocations, gPAPP type. In addition, close to the mutation two silent mutations, c.716T>C and c.719C>T were inserted to generate a ClaI restriction site. Flp-mediated recombination removed the neomycin cassette. Germline cre-mediated recombination results in stable inversion of the two exons and expression of the mutation. RT-PCR of homozygotes shows absence of the transcript seen in wild-type mice but shows two transcript variants that lack exon 2 or exon 2 and exon 3, indicating altered splicing of the modified allele. If translated, these would lead to premature stop codons. (J:273179)