Schematic model of the injection fragment for generating transgenic mice. The upper part of the figure shows the genomic structure of the mouse tec gene. The 5′ flanking region and the first intron are represented by thick and thin bars, respectively and the first exon is shown as a shaded box. Restriction enzyme sites are P; PstI, A; ApaI, S; SalI, X; XhoI, Sm;SmaI, Nc; NcoI, Nh; NheI, Ac; AccIII, and Sa; SacI. The lower part illustrates the structure of the injection fragment. The tec promoter (−1948 to +22), thebcr/abl (p210) cDNA (b3a2 type), and the SV40 early splicing and poly(A) signals are shown as white, black, and shaded boxes, respectively. The primers used for RT-PCR (P1-P4) are also indicated.