Identification of sensory dysfunction and nervous structure changes in knockout mice.

Objectives: Mutation in human gene has been implicated in hereditary sensory and autonomic neuropathy type IIB. We aimed to knock out in mice and explored its phenotypes to determine whether the genetic impairments and behavioral changes can mirror manifestations noted in humans.

Methods: We used CRISPR/Cas9 technology to knockout the gene in the C57BL/6 J mouse. After confirming the knockout was successful by Sanger sequencing and Western blot, sensory function was measured using the hot plate test and the 50% paw withdrawal threshold test. In addition, standard microscopy and transmission electron microscopy were performed to observe the structural changes of the dorsal root ganglion sensory neuron and the sciatic nerve.

Results: DNA sequencing and Western blot analysis confirmed the mutation in the mutation gene and the loss of expression of its products. knockout mice exhibited heat pain insensitivity and mechanical hyperalgesia. Interestingly, limb damage was found in some homozygotes. Demyelination in the sciatic nerve was common. Golgi bodies were turgid in dorsal root ganglion neuron.

Conclusions: These findings indicate that peripheral neuropathy is common in KO mice. We believe this novel animal model is likely to have significant future potential as a reliable model for the evaluation of peripheral neuropathy and its complications.