Defensive and offensive behaviors in social interaction settings in a Kleefstra syndrome mouse model

Kleefstra syndrome in humans is characterized by general delay in development, intellectual disability and autistic features. The mouse model of this disease (Ehmt1^+/-) expresses anxiety, autistic-like traits, and aberrant social interactions with non-cagemates. To investigate how Ehmt1^+/- mice behave with unfamiliar conspecifics, we allowed adult, male animals to freely interact for 10 minutes in a neutral, novel environment within a host-visitor setting. In 17 out of 74 trials there were defensive and offensive behaviors. Our key finding was that Ehmt1^+/- mice displayed defensive postures, attacking and biting; in contrast, wild-type (WT) interacting with other WT did not enact such behaviors. Further, if there was a fight between an Ehmt1^+/- and a WT mouse, it was always the Ehmt1^+/- who initiated these behaviors.