Single-Cell Transcriptomics Reveals Neural Fate Reprogramming in RARS2-Related Pontocerebellar Hypoplasia

Although RARS2-related mitochondrial dysfunction has been linked to impaired brain development, the cellular and molecular mechanisms remain largely unknown. In this study, we established a zebrafish model of rars2 deficiency and combined single-cell RNA sequencing (scRNA-seq) with immunofluorescence, in situ hybridization, and electron microscopy to dissect neural lineage alterations.

Our analyses revealed a marked disruption of neurogenesis, accompanied by activation of glial and extracellular matrix–related programs. Key neurogenic transcription factors, including neurod4, her6, and pou3f1, were significantly downregulated, whereas glial- and stress-associated regulators such as hmgb1a, fabp7a, and foxp1b were strongly upregulated. Pathway enrichment indicated defects in RNA splicing and mitochondrial translation, together with compensatory metabolic and inflammatory responses.