• Duchenne muscular dystrophy (DMD) is a severe, progressive, muscle-wasting disease that leads to difficulties with movement and premature death.
• Duchenne muscular dystrophy (DMD) is caused by mutations in the DMD gene. These mutations frequently entail deletions of one or more exons, which disrupt the open reading frame and introduce a premature stop codon. This leads to the production of a nonfunctional truncated dystrophin protein, resulting in a severe muscle degeneration phenotype.
• The exons 45-50 of mouse Dmd gene were deleted in B-Dmd KO(del45-50) mice.
• Mouse Dmd mRNA and DMD protein were detectable in wild-type C57BL/6JNifdc mice but not in homozygous B-Dmd KO(del45-50) mice.
• This product is used for pharmacodynamics of Duchenne muscular dystrophy.

Gene targeting strategy for B-Dmd KO(del45-50) mice. The exons 45-50 of mouse Dmd gene were deleted in B-Dmd KO(del45-50) mice.

Strain specific analysis of DMD mRNA expression in wild-type C57BL/6JNifdc mice and B-Dmd KO(del45-50) mice by RT-PCR. Heart and skeletal muscle RNA were isolated from wild-type C57BL/6JNifdc mice (+/+) and homozygous B-Dmd KO(del45-50) mice (H/Y), then cDNA libraries were synthesized by reverse transcription, followed by PCR with mouse Dmd primers. Dmd mRNA was detectable in wild-type C57BL/6JNifdc mice (+/+) but not the homozygous B-Dmd KO(del45-50) mice (-/Y).

Western blot analysis of DMD protein expression in B-Dmd KO(del45-50) mice. Various tissue lysates were collected from wild-type C57BL/6JNifdc mice (+/+) and B-Dmd KO(del45-50) mice (-/Y), and then analyzed by western blot with anti-Dystrophin antibody (Sigma, D8168). 50 μg total proteins were loaded for western blotting analysis. DMD was detectable in heart, skeletal muscle and skin from wild-type C57BL/6JNifdc mice (+/+) but not homozygous B-Dmd KO(del45-50) mice (-/Y).

Behavioral performance in wild-type C57BL/6JNifdc and homozygous B-Dmd KO(del45-50) mice. Grip strength and rotarod tests were conducted to assay the behavioral performance in wild-type C57BL/6JNifdc and homozygous B-Dmd KO(del45-50) mice (male, 5-month-old, n=9). A. Grip strength results showed the strength produced by forelimb was ~20 N/kg in homozygous B-Dmd KO(del45-50) mice, which was significant weaker than that in wild-type control mice. All grip strength measurements are normalized to the individual animal’s body weight. B. Rotarod tests were performed to assay the motor coordination. The latency to fall was significantly decreased in homozygous B-Dmd KO(del45-50) mice. Values are expressed as mean ± SEM. Significance was determined by two-way ANOVA test.  *P < 0.05, **P < 0.01, ***P < 0.001.