Targeted disruption of the mouse Adamts13 gene. (A) Structure of the targeted locus in the mouse Adamts13 gene. Exons are represented by filled boxes. A neomycin-resistance cassette (neo), in the opposite transcriptional orientation, and a forward-oriented diphtheria toxin A fragment expression cassette (DT-A) are indicated. Homologous fragments are indicated by dotted lines; the HindIII fragments detected by Southern analysis of the wild type and targeted alleles are indicated by double-headed arrows. The sites of primers used for the genotyping PCR (F, R1, and R2) are indicated by arrows. H indicates HindIII; S, SalI; E, EcoRI; N, NcoI. (B) Southern blot analysis. gDNA from offspring obtained from heterozygous intercrosses was digested with HindIII and detected with the 5′-specific probe (wild type: 14.5 kb; targeted allele: 6.6 kb). (C) RT-PCR analysis. Total RNA isolated from mouse liver was reverse-transcribed and amplified using the Adamts13-specific primer set to generate a 540-bp fragment.