Loss ofUBE3Aimpacts both neuronal and non-neuronal cells in human cerebral organoids

Angelman syndrome is a neurodevelopmental disorder caused by (epi)genetic lesions of maternal UBE3A . Research has focused largely on the role of UBE3A in neurons due to its imprinting in that cell type. Yet, evidence suggests there may be broader neurodevelopmental impacts of UBE3A dysregulation. Human cerebral organoids might reveal these understudied aspects of UBE3A as they recapitulate diverse cell types of the developing human brain. We performed scRNAseq on organoids to reveal the effects of UBE3A disruption on cell type-specific compositions and transcriptomic alterations. In the absence of UBE3A , progenitor proliferation and structures were disrupted while organoid composition shifted away from proliferative cell types. We observed impacts on non-neuronal cells, including choroid plexus enrichment. Furthermore, EMX1+ cortical progenitors were negatively impacted, disrupting corticogenesis, and potentially delaying excitatory neuron maturation. This work reveals novel impacts of UBE3A on understudied cell types and related neurodevelopmental processes and elucidates potential new therapeutic targets. Teaser Human cerebral organoids exhibit compositional and transcriptomic alterations in both neuronal and non-neuronal cells in the absence of UBE3A .