Figure 1.

Generation of gene targeted Sec22b alleles. (a) Sec22b-conditional gene trapped mice (tm1a), with a FRT-flanked gene trap inserted between exons 2 and 3 were mated to FLP-recombinase transgenic mice to create floxed (fl) mice, with LoxP sites flanking exon 3. Floxed mice were mated to EIIa-Cre to generate the germline null allele (Sec22b⁻), or to Vav1-Cre or CD11c-Cre transgenic mice to generate tissue specific Sec22b deficiency. Binding sites for genotyping primers (F1, F2, R1, R2, R3) are indicated with half arrowheads. (b) PCR with primers F1 and R1 detects the insertion of the conditional gene trap in Sec22b (tm1a). (c) PCR with primers F1 and R2 detects the excision of the conditional gene trap by FLP recombinase and distinguishes between Sec22b^fl homozygous and heterozygous mice. (d) Competitive PCR with primers F1, F2, and R3 detects the excision of exon 3 of Sec22b and distinguishes between Sec22b⁻ heterozygous and homozygous mice. (e) PCR on genomic DNA isolated from peripheral blood of a surviving Sec22b^fl/fl; Vav1-Cre⁺ mouse and a Sec22b^fl/+; Vav1-Cre⁻ littermate control, compared to DNA from Sec22b^+/− mice. Gel images (b–e) are cropped. Full-length images may be found in Supplementary Fig. S1a–c.