Unbiased PCR-free spatio-temporal mapping of the mtDNA mutation spectrum reveals brain region-specific responses to replication instability

BMC Biology

Mie Kubota-Sakashita¹  Emilie Kristine Bagge¹  Takaoki Kasahara²  Noriko Fujimori-Tonou³  Tadafumi Kato⁴ 

[1] Laboratory for Molecular Dynamics of Mental Disorders, RIKEN Center for Brain Science, Wako, Saitama, Japan;Laboratory for Molecular Dynamics of Mental Disorders, RIKEN Center for Brain Science, Wako, Saitama, Japan;Current address: Career Development Program, RIKEN Center for Brain Science, Wako, Saitama, Japan;Laboratory for Molecular Dynamics of Mental Disorders, RIKEN Center for Brain Science, Wako, Saitama, Japan;Current address: Support Unit for Bio-Material Analysis, Research Resources Division, RIKEN Center for Brain Science, Wako, Saitama, Japan;Laboratory for Molecular Dynamics of Mental Disorders, RIKEN Center for Brain Science, Wako, Saitama, Japan;Department of Psychiatry and Behavioral Science, Juntendo University, Graduate School of Medicine, Hongo 2-1-1, Bunkyo, Tokyo 113-8421, Japan;

关键词: Mitochondrial DNA;    Polymerase gamma;    Polg;    Ageing;    Mitochondrion;    mtDNA mutation;    Paraventricular thalamic nucleus;    Nucleus accumbens;    Substantia nigra;    Dorsal raphe;   

DOI  :  10.1186/s12915-020-00890-5

来源: Springer

【 摘 要 】

BackgroundThe accumulation of mtDNA mutations in different tissues from various mouse models has been widely studied especially in the context of mtDNA mutation-driven ageing but has been confounded by the inherent limitations of the most widely used approaches. By implementing a method to sequence mtDNA without PCR amplification prior to library preparation, we map the full unbiased mtDNA mutation spectrum across six distinct brain regions from mice.ResultsWe demonstrate that ageing-induced levels of mtDNA mutations (single nucleotide variants and deletions) reach stable levels at 50 weeks of age but can be further elevated specifically in the cortex, nucleus accumbens (NAc), and paraventricular thalamic nucleus (PVT) by expression of a proof-reading-deficient mitochondrial DNA polymerase, PolgD181A. The increase in single nucleotide variants increases the fraction of shared SNVs as well as their frequency, while characteristics of deletions remain largely unaffected. In addition, PolgD181A also induces an ageing-dependent accumulation of non-coding control-region multimers in NAc and PVT, a feature that appears almost non-existent in wild-type mice.ConclusionsOur data provide a novel view of the spatio-temporal accumulation of mtDNA mutations using very limited tissue input. The differential response of brain regions to a state of replication instability provides insight into a possible heterogenic mitochondrial landscape across the brain that may be involved in the ageing phenotype and mitochondria-associated disorders.

【 授权许可】

CC BY