Multiple autism-like behaviors in a novel transgenic mouse model

Autism spectrum disorder (ASD) diagnoses are behaviorally based with no defined universal biomarkers, occur at a 1:110 ratio in the population, and predominantly affect males compared to females at approximately a 4:1 ratio. One approach to investigate and identify causes of ASD is to use organisms that display abnormal behavioral responses that model ASD-related impairments. This study describes a novel transgenic mouse, MALTT, which was generated using a forward genetics approach. It was determined that the transgene integrated within a non-coding region on the X chromosome. The MALTT line exhibited a complete repertoire of ASD-like behavioral deficits in all three domains required for an ASD diagnosis: reciprocal social interaction, communication, and repetitive or inflexible behaviors. Specifically, MALTT male mice showed deficits in social interaction and interest, abnormalities in pup and juvenile ultrasonic vocalization communications, and exhibited a repetitive stereotypy. Abnormalities were also observed in the domain of sensory function, a secondary phenotype prevalently associated with ASD. Mapping and expression studies suggested that the Fam46 gene family may be linked to the observed ASD-related behaviors. The MALTT line provides a unique genetic model for examining the underlying biological mechanisms involved in ASD-related behaviors.

Research highlights▶ The MALTT line shows multiple social behavior deficits and a progressive circling stereotypy. ▶ Juvenile MALTT mice exhibit minimal ultrasonic communication during a social assay. ▶ A variety of sensory-related abnormalities are observed in the MALTT line. ▶ Fam46d expression is strongly upregulated in the MALTT line.