Human mitochondrial DNA with large deletions repopulates organelles faster than full-length genomes under relaxed copy number control

AUTOR(ES)

Diaz, Francisca

FONTE

Oxford University Press

RESUMO

Partially-deleted mitochondrial DNA (ΔmtDNA) accumulates during aging of postmitotic tissues. This accumulation has been linked to decreased metabolic activity, increased reactive oxygen species formation and the aging process. Taking advantage of cell lines with heteroplasmic mtDNA mutations, we showed that, after severe mtDNA depletion, organelles are quickly and predominantly repopulated with ΔmtDNA, whereas repopulation with the wild-type counterpart is slower. This behavior was not observed for full-length genomes with pathogenic point mutations. The faster repopulation of smaller molecules was supported by metabolic labeling of mtDNA with [3H]thymidine during relaxed copy number control conditions. We also showed that hybrid cells containing two defective mtDNA haplotypes tend to retain the smaller one as they adjust their normal mtDNA copy number. Taken together, our results indicate that, under relaxed copy number control, ΔmtDNAs repopulate mitochondria more efficiently than full-length genomes.

Documentos Relacionados

• A Drosophila full-length cDNA resource
• Isolation of a full-length cDNA encoding Brassica napus mitochondrial chaperonin-60.
• Generation and initial analysis of more than 15,000 full-length human and mouse cDNA sequences
• SMART amplification combined with cDNA size fractionation in order to obtain large full-length clones
• High-efficiency cloning of full-length cDNA.