The exon encoding amino acids 23 through 69 was replaced with a construct containing a splice acceptor and a modified partial cDNA encoding the p80 splice form. Unlike the Dab1tm2Cpr. allele, the cDNA was NOT modified to eliminate the 5 tyrosines residues (185, 198, 200, 220, 232) that are potential phosphorylation sites. (J:79475)