title: The low abundance of clonally expanded mitochondrial DNA point mutations in aged substantia nigra neurons.
abstract: Clonally expanded mitochondrial DNA (mtDNA) deletions accumulate with age in human substantia nigra (SN) and high levels cause respiratory chain deficiency. In other human tissues, mtDNA point mutations clonally expand with age. Here, the abundance of mtDNA point mutations within single SN neurons from aged controls was investigated. From 31 single cytochrome c oxidase normal SN neurons, only one clonally expanded mtDNA point mutation was identified, suggesting in these neurons mtDNA point mutations occur rarely, whereas mtDNA deletions are frequently observed. This contrasts observations in mitotic tissues and suggests that different forms of mtDNA maintenance may exist in these two cell types.
authors.affiliation: Newcastle University Centre for Brain Ageing and Vitality, Institute for Ageing and Health, Newcastle University, UK.
authors.forename: Amy K
authors.initials: AK
authors.lastname: Reeve
authors.forename: Kim J
authors.initials: KJ
authors.lastname: Krishnan
authors.forename: Geoffrey
authors.initials: G
authors.lastname: Taylor
authors.forename: Joanna L
authors.initials: JL
authors.lastname: Elson
authors.forename: Andreas
authors.initials: A
authors.lastname: Bender
authors.forename: Robert W
authors.initials: RW
authors.lastname: Taylor
authors.forename: Christopher M
authors.initials: CM
authors.lastname: Morris
authors.forename: Doug M
authors.initials: DM
authors.lastname: Turnbull
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000502:physiology*; D001483:Base Sequence; D004272:DNA, Mitochondrial / Q000235:genetics*; D003576:Electron Transport Complex IV / Q000235:genetics; D005260:Female; D006801:Humans; D008297:Male; D008938:Mitosis; D009474:Neurons / Q000166:cytology; D017354:Point Mutation; D013378:Substantia Nigra / Q000166:cytology* / Q000378:metabolism*
chemical_list: D004272:DNA, Mitochondrial; D003576:Electron Transport Complex IV