Fig. 5

Impairment of α-secretase cleavage resulted in repetitive and social behavior abnormalities in mice. a Schematic representation of CRISPR/Cas9 knock-in method used to generate mutant I1254T mice by mutating “ATA” (Ile) to “ACG” (Thr) at the major α-cleavage site of CNTNAP2. b Body weight record of WT and I1254T mice. The weight of both mice was recorded daily, and no significant difference was found between mutants and WT mice (WT, n = 15; I1254T, n = 15). c Isolation-induced ultrasonic vocalizations (UsVs) test. The numbers of distress calls from infants of WT and mutants were detected at the age of P3, P6 and P12 (WT, n = 13; I1254T, n = 13). d Juvenile play test. Time involved in social interaction, as well as repetitive behaviors like grooming in WT and I1254T mutant mice were measured at the age of P21 when interacting with unfamiliar mice (n = 10 per group: male = 5, female = 5). e, f T maze and three chamber sociability tests performed at 7-week-old WT and mutants. I1254T mutation at the α-cleavage site increased repetitive behavior abnormalities in T maze (e) and decreased social interactions (f) in I1254T mutants, and C79 overexpression rescued the ASD-like behaviors (n = 12 per group: male = 6, female = 6). g–i Social and repetitive behavior tests in Cntnap2^−/− mice. C79 overexpression rescued the social interactions (g, i) and repetitive behaviors (h) in Cntnap2^−/− mice (n = 11: male = 6, female = 5 in WT and KO groups; n = 12: male = 6, female = 6 in KO + C79 group). Statistical significance was assessed by either one- or two-way ANOVA followed by Turkey or Bonferroni’s test. *p < 0.05; **p < 0.01; ***p < 0.001; ****p < 0.0001. All the results are expressed as mean ± SEM