Cell-type-specific dysregulation of gene expression due to Chd8 haploinsufficiency during mouse cortical development

Abstract

Disruptive variants in the chromodomain helicase CHD8 are associated with risk for autism spectrum disorder (ASD). CHD8 haploinsufficiency is hypothesized to contribute to ASD by perturbing neurodevelopmental gene expression. However, insight into cell-type-specific transcriptional effects of CHD8 haploinsufficiency remains limited. We used single-cell and single-nucleus RNA sequencing to identify dysregulated genes in the embryonic and juvenile Chd8^+/- mouse cortex. Chd8 and other ASD risk-associated genes showed a convergent expression trajectory conserved between mouse and human developing cortex, increasing from progenitor zones to the cortical plate. Genes associated with neurodevelopmental disorders or involved in chromatin remodeling and neuron projection development were dysregulated in Chd8^+/- embryonic radial glia. Genes implicated in synaptic activity and organization were dysregulated in Chd8^+/- postnatal excitatory cortical neurons, suggesting impaired synaptogenesis. Our findings reveal complex patterns of transcriptional dysregulation due to Chd8 haploinsufficiency, potentially with distinct impacts on progenitors and maturing neurons in the excitatory neuronal lineage.

Keywords: ASD; CHD8; autism spectrum disorder; cortical development; gene regulation; mouse model; neurodevelopment; neurodevelopmental disorders; single-cell transcriptomics.