Gross Mosaic Pattern of Mitochondrial DNA Deletions in Skeletal Muscle Tissues of an Individual Adult Human Subject

Abstract

Using polymerase chain reaction techniques, the patterns of mitochondrial DNA deletions (which characteristically occur at low abundance during ageing) were compared in different skeletal muscle samples of an adult human subject. In one particular section of the biceps muscle, an unusual pattern of mitochondrial DNA deletions was detected; the common 4977 bp deletion was absent, but other deletions were observed. In pectoralis (chest) muscle, deletions commonly seen in normal adults were readily detected, including the 4977 bp deletion. Significantly, different patterns of mtDNA deletions were found in two adjacent parts of the same biceps muscle sample: one was the unusual pattern mentioned above, but the other part clearly contained the 4977 bp deletion. The results therefore demonstrate a gross mosaic pattern of mtDNA deletions in the skeletal muscle tissues of an individual human subject.