These ZFN mutant rats were produced by injecting zinc finger nuclease targeting exon 1 of rat Pde4b into Sprague Dawley embryos. The 16-bp frameshift deletion (AGCGGCGTCGCTTCAC) in exon 1 in rat was created in the mutant founders. These mutant founders were backcrossed with Sprague Dawley to produce heterozygous offspring, which were then intercrossed to produce homozygous and heterozygous offspring.