Cochlear mitochondrial DNA3867bp deletion in aged mice
Zhang, X.; Han, D.; Ding, D.; Dai, P.; Yang, W.; Jiang, S.; Salvi, R.J.
Chinese Medical Journal 115(9): 1390-1393
2002
ISSN/ISBN: 0366-6999 PMID: 12411120 Document Number: 542009
Objectives: To study the status of cochlear mitochondrial DNA (mtDNA) and to determine the location of mtDNA deletion in aged mice. Methods: We detected cochlear mtDNA in 2, 7-10 and 17-19 month old mice by nested polymerase chain reaction (PCR) and DNA sequencing. Results: mtDNA3867bp deletions were found in the cochleae of aged mice. The deletion occurred within nt9103-nt12970 and were flanked by 15 base pair direct repeats. Comparing the incidence of mtDNA3867bp deletions, 17-19 month old mice (7/8) were significantly higher than 7-10 month old mice (4/16). The deletion was not observed in 2 month old mice (0/7). The ratio of deleted mtDNA/total mtDNA in 17-19 month old mice was higher than in 7-10 month old mice (P<0.001). Conclusion: Cochlear mtDNA 3867bp deletion in aged mice may be related to presbycusis.