Increased repetitive self-grooming occurs in Pax2 mutant mice generated using CRISPR/Cas9.

Autism spectrum disorder (ASD) is a neurodevelopmental disorder characterized by impaired social interaction and communication, and repetitive or restricted interest and behaviors. However, the specific pathogenesis of ASD is still unclear. It has been widely accepted that genetic and environmental risk factors are associated with the pathogenesis of ASD. Paired box2 (Pax2) gene encodes a transcription factor that plays an important role in the development of the central nervous system of humans and mice. In this study, we constructed Pax2 heterozygous gene knockout (Pax2+/-) mice using CRISPR/Cas9 technology and performed several autistic-like behavioral assays, including self-grooming test, sociability approach, the elevated plus maze test and Y maze test. Results showed increased repetitive self-grooming and possible abnormal anxiety-like behavior occur in Pax2+/- mice. Furthermore, no changes were observed in the abilities of sociability and working memory in Pax2+/- mice compared to wild-type C57BL/6 J mice. Finally, we speculated that possible mechanism of abnormal autistic-like behaviors due to the deletion of Pax2 gene.