Gene by environment interaction mouse model reveals a functional role for 5-hydroxymethylcytosine in neurodevelopmental disorders

Mouse knockouts of Cntnap2 exhibit altered neurodevelopmental behavior and a genome-wide disruption of 5-hydroxymethylcytosine (5hmC). Here we examined whether adult Cntnap2 heterozygous mice (Cntnap2+/-, lacking behavioral or neuropathological abnormalities) subjected to a prenatal stress would have disruptions in brain 5hmC levels and exhibit altered behaviors similar to the knockout mice. Adult prenatally stressed Cntnap2+/- female mice showed repetitive behaviors and altered sociability, similar to the homozygote phenotype. Genomic profiling revealed disruptions in hippocampal and striatal 5hmC levels that were correlated to altered transcript levels of genes linked to these phenotypes (e.g., Reln, Dst, Trio and Epha5). Chromatin-immunoprecipitation coupled with high-throughput sequencing and hippocampal nuclear lysate pull-down data indicated that 5hmC abundance alters the binding of the transcription factor CLOCK near the promoters of differentially expressed genes (e.g., Palld, Gigyf1, and Fry), providing a mechanistic role for 5hmC (disruption of transcription factor binding) in gene regulation of developmentally important genes.