Please use this identifier to cite or link to this item: http://hdl.handle.net/1959.13/916912
- Region-specific changes in mitochondrial D-loop in aged rat CNS
McInerny, Simone C.;
Brown, Amanda L.;
Smith, Douglas W.
- The University of Newcastle. Faculty of Health, School of Biomedical Sciences and Pharmacy
- Impaired mitochondrial oxidative phosphorylation (OXPHOS) is considered a cause of aging. A reduction in mitochondrial DNA (mtDNA) replication and/or transcription may contribute to this OXPHOS diminution. Impairments in the displacement (D) loop, or non-coding, region of the mitochondrial genome, or accumulation of mtDNA mutations, may affect mtDNA replication and transcription. We determined the effects of age on the D-loop and on mtDNA deletion mutations in the spinal cord, medulla, midbrain, cerebellum, striatum, and cerebral cortex of Fischer 344 rats. D-loop, 7S DNA levels were reduced by 3-fold in striatum, 2.5-fold in cortex, and 2-fold in the spinal cord of older animals. We did not detect a population of mtDNA affected by the most prevalent known (ND4-containing) deletions, indicating they do not comprise a significant portion of total mtDNA. However, we detected an age-related and region-specific increase in the common deletion, which comprised 0.0003–0.0007% of total mtDNA. Mitochondrial genome copy number varied between regions, in addition to an overall 18% decrease with age across the whole brain. These results suggest the age-related decline in OXPHOS may be related to a reduction in D-loop function.
- Mechanisms of Ageing and Development Vol. 130, Issue 5, p. 343-349
- Publisher Link
mitochondrial genome mutation;
hypothesis of aging;
real-time quantitative PCR;
mitochondrial genome deletions;
- Resource Type
- journal article