Consequences of postnatal Tshz3 deletion: implications for autism spectrum disorder

We recently identified heterozygous deletions of the gene TSHZ3, which encodes a Zn-finger transcription factor, in patients with a syndrome including autistic features and provided evidence in mice for a link between Tshz3 haploinsufficiency, defects in cortical projection neurons (CPNs) and autism spectrum disorder (ASD)-like abnormalities. To get more insight into when and where TSHZ3 is required for the proper development of the brain, we generated and characterized a novel mouse model of conditional Tshz3 deletion in projection neurons from postnatal day 2-3 onward. These mice exhibit altered cortical expression of genes encoding for synaptic components, electrophysiological and synaptic changes in layer 5 CPNs, impaired corticostriatal glutamate transmission and plasticity, as well as strong ASD-relevant behavioral deficits. These data, by revealing a crucial postnatal role of TSHZ3 in the development and function of the corticostriatal circuitry that might be determinant for ASD pathogenesis, offer a novel ASD model and further open the possibility for an early postnatal therapeutic window for the syndrome linked to TSHZ3 haploinsufficiency. Overall design: Three independent replicates, each containing cortices from 3-4 mice (P34), were prepared for analysis.