Polg, also known as DNA polymerase gamma, is the gene encoding the mitochondrial DNA polymerase responsible for the replication of the mitochondrial genome [1,2,3]. This process is crucial for maintaining mitochondrial function, which is essential for cellular energy production and various biological processes. Genetic models, like the zebrafish polg2 mutant line, can be valuable for studying Polg-related functions [4].

Mutations in Polg are the most common cause of inherited mitochondrial disorders, with around 2% of the population carrying these mutations [1]. The resulting POLG-related disorders present a continuum of phenotypes from infancy to late adulthood, including Alpers-Huttenlocher syndrome, childhood myocerebrohepatopathy spectrum, myoclonic epilepsy myopathy sensory ataxia, ataxia neuropathy spectrum, autosomal recessive and dominant progressive external ophthalmoplegia [1,2]. In the zebrafish polg2 knock-out model, mutants recapitulate human POLG-related phenotypes such as mitochondrial DNA depletion, altered mitochondrial network and dynamics, and reduced mitochondrial respiration, along with morphological and locomotor defects [4].

In conclusion, Polg is essential for mitochondrial DNA replication and maintaining mitochondrial function. Studies using genetic models, like the zebrafish polg2 knock-out, have revealed its role in POLG-related disorders, which are a significant cause of inherited mitochondrial diseases. Understanding Polg function provides insights into the pathophysiology of these disorders and may inform future treatment strategies.