Rapgef1^{Gt(pGT1.8geo)5Pgr}

The gene trap insertion is located in the 59 kb intron 1, approximately 16 kb 3' to exon 1. The predicted protein deduced from this fusion gene contains the first 19 amino acids of the endogenous protein fused to beta-galactosidase and neomycin phosphotransferase. This fusion protein will lack the carboxy-terminal CDC25-type catalytic domain, the 4 central Crk SH3-binding domains and the central p130Cas SH3-binding domain. However, RT-PCR and western blot analysis has shown that this allele generates less than 1% mRNA containing all coding exons and no more than 5% normal protein suggesting that some transcripts splice around the gene trap insertion site. Therefore, this is a hypomorphic rather than a null allele. (J:80219)