Crk^{Gt(pU-Hachi)8104Imeg}

The integration of a gene trap vector into the coding sequence of the endogenous allele resulted in an isoform specific disruption. Sequence analysis revealed that the insertion prevented the translation of the carboxy terminal SH3 domain, thereby affecting the isoform containing both SH3 domains and not the isoform that contains only the amino terminal SH3 domain. Western blot analysis of homozygous mutant mice showed the presence of two mutant isoforms structurally similar to the wild-type splice variant containing single the single SH3 domains but lacking a tyrosine at position 221 and having additional amino acids encoded from the gene trap vector splice acceptor sequence on the carboxyl terminus. (J:59071)