Cerebellar organoids model cell type-specific FOXP2 expression during human cerebellar development.

Human cerebellar development is unique and cannot be fully replicated in animal models. Although human stem cell-derived cerebellar organoid models are increasingly being applied to model cerebellar diseases, their potential to provide insight into normal human cerebellar development remains underexplored. Here, we used CRISPR-based gene editing in cerebellar organoids as an approach for modelling specific features of early human cerebellar development. Forkhead box protein P2 (FOXP2) is a transcription factor associated with speech and language development that is highly expressed in the developing brain. However, little attention has been directed to the study of FOXP2 in the early developing cerebellum. We generated a fluorescent FOXP2 reporter line in human induced pluripotent stem cells to enable the characterisation of FOXP2-expressing cells during cerebellar organoid differentiation. Through transcriptomic profiling of FOXP2 reporter cerebellar organoids and cross-referencing with existing cerebellar datasets, we describe the expression and identify potential downstream targets of FOXP2 in the early developing human cerebellum. Our results highlight expression of FOXP2 in early human Purkinje cells and cerebellar nuclei neurons, and the vulnerability of these cell populations to neurodevelopmental disorders.