Effects of a postnatalAtrxconditional knockout in neurons on autism-like behaviours in male and female mice

Background Alpha-thalassemia/mental retardation, X-linked, or ATRX , is an autism susceptibility gene that encodes a chromatin remodeler. Mutations of ATRX result in the ATR-X intellectual disability syndrome and have been identified in autism spectrum disorder (ASD) patients. The mechanisms by which ATRX mutations lead to autism and autistic-like behaviours are not yet known. To address this question, we generated mice with postnatal Atrx inactivation in excitatory neurons of the forebrain and performed a battery of behavioural assays that assess autistic-like behaviours. Methods Male and female mice with a postnatal conditional knockout of Atrx were tested in a battery of behavioural tests that assess autistic features. We utilized paradigms that measure social behaviour, repetitive and stereotyped behaviours, as well as sensory gating. Statistics were calculated by two-way repeated measures ANOVA with Sidak’s multiple comparison test or unpaired Student’s T-tests as indicated. Results The behaviour tests revealed no significant differences between Atrx -cKO and control mice. We identified sexually dimorphic changes in odor habituation and discrimination; however, these changes did not correlate with social deficits. We additionally observed sex-specific differences in sociability, vertical episodes, and acoustic startle response when results were analyzed by sex. Conclusion The postnatal knockout of Atrx in forebrain excitatory neurons does not lead to autism-related behaviours in male or female mice.