Development of mitochondrial base editing technology and its application in animals

Mitochondrial DNA (mtDNA) mutations constitute major genetic determinants of mitochondrial disorders and contribute to the progressive dysfunction of energy-demanding tissues. However, precise manipulation of the mitochondrial genome remains a formidable challenge for decades due to the unique structural and biological features of mitochondria. Recent breakthroughs in mitochondrial base-editing technologies address longstanding barriers in mitochondrial genome engineering by enabling programmable nucleotide conversion without introducing DNA double-strand breaks. Mitochondrial base editing evolves rapidly from a proof-of-concept strategy in cultured cells into a versatile platform for generating animal models, dissecting mitochondrial gene function and exploring therapeutic interventions for mitochondrial diseases. Recent advances enable the creation of animals carrying defined pathogenic mtDNA variants and provide initial evidence supporting the feasibility of in vivo mitochondrial genome correction and disease amelioration. Here, we review the evolution of mitochondrial base-editing technologies and summarize the major editing platforms, with particular emphasis on recent advances in editor engineering, expansion of targeting capabilities, generation of animal disease models and emerging therapeutic applications. We further discuss the remaining challenges, including editing precision, target-site accessibility, delivery efficiency, and comprehensive safety evaluation. Finally, we highlight future opportunities for developing next-generation mitochondrial genome-editing systems and advancing their translation toward clinical applications.