Zebrafish lacking functional DNA polymerase gamma survive to juvenile stage, despite rapid and sustained mitochondrial DNA depletion, altered energetics and growth
Autor: | Jennifer J. Rahn, Jennifer E. Bestman, Krista D. Stackley, Sherine S.L. Chan |
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Jazyk: | angličtina |
Rok vydání: | 2015 |
Předmět: |
Mitochondrial DNA
Mitochondrial disease Mutant DNA-Directed DNA Polymerase medicine.disease_cause DNA Mitochondrial 03 medical and health sciences chemistry.chemical_compound 0302 clinical medicine Adenosine Triphosphate Oxygen Consumption Genetics medicine Animals Regeneration Zebrafish Molecular Biology Polymerase 030304 developmental biology 0303 health sciences Mutation biology Zebrafish Proteins medicine.disease biology.organism_classification Molecular biology Survival Analysis DNA Polymerase gamma chemistry Models Animal biology.protein Animal Fins Ethidium bromide Genetic Engineering Glycolysis 030217 neurology & neurosurgery DNA |
Zdroj: | Nucleic Acids Research |
ISSN: | 1362-4962 0305-1048 |
Popis: | DNA polymerase gamma (POLG) is essential for replication and repair of mitochondrial DNA (mtDNA). Mutations in POLG cause mtDNA instability and a diverse range of poorly understood human diseases. Here, we created a unique Polg animal model, by modifying polg within the critical and highly conserved polymerase domain in zebrafish. polg(+/-) offspring were indistinguishable from WT siblings in multiple phenotypic and biochemical measures. However, polg(-/-) mutants developed severe mtDNA depletion by one week post-fertilization (wpf), developed slowly and had regenerative defects, yet surprisingly survived up to 4 wpf. An in vivo mtDNA polymerase activity assay utilizing ethidium bromide (EtBr) to deplete mtDNA, showed that polg(+/-) and WT zebrafish fully recover mtDNA content two weeks post-EtBr removal. EtBr further reduced already low levels of mtDNA in polg(-/-) animals, but mtDNA content did not recover following release from EtBr. Despite significantly decreased respiration that corresponded with tissue-specific levels of mtDNA, polg(-/-) animals had WT levels of ATP and no increase in lactate. This zebrafish model of mitochondrial disease now provides unique opportunities for studying mtDNA instability from multiple angles, as polg(-/-) mutants can survive to juvenile stage, rather than lose viability in embryogenesis as seen in Polg mutant mice. |
Databáze: | OpenAIRE |
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