Related Experiment Video
Updated: Jul 31, 2026

Methodology for Accurate Detection of Mitochondrial DNA Methylation
Published on: May 20, 2018
Prominent mitochondrial DNA recombination intermediates in human heart muscle
O A Kajander1, P J Karhunen, I J Holt
1Institute of Medical Technology and Tampere University Hospital, FIN-33014 University of Tampere, Finland.
Abstract:
Recombination intermediates containing four-way (Holliday) junctions are generated during DNA repair and replication in many systems, including yeast mitochondrial DNA (mtDNA). In contrast, convincing evidence for recombination in mammalian mtDNA is lacking. We have used two-dimensional agarose-gel electrophoresis to analyse non-linear forms of mtDNA in human heart muscle. Replication intermediates from both the coupled and strand-asynchronous mtDNA replication pathways were detected. An additional class of non-linear molecules, with the electrophoretic properties of four-way junctions, was also prominent. These molecules were insensitive to topoisomerase I or RNase H, but were diminished by branch migration or RuvC treatment. Junctional molecules were detected in all regions of the mitochondrial genome, were found in myocardial DNA from young and old adults, but were present at lower levels in skeletal muscle and placenta. We suggest that they could represent intermediates of mtDNA repair, given their prevalence in the oxyradical-rich environment of heart muscle mitochondria.
Related Concept Videos
Animal Mitochondrial Genetics
Export of Mitochondrial and Chloroplast Genes
Conservative Site-specific Recombination and Phase Variation
The recognition sites for Cre recombinase called LoxP...
Mitochondrial Membranes
The Inner Mitochondrial Membrane
Crossing Over

