Mitochondrial DNA is more heterogeneous than was thought, a study of normal and cancerous human cells shows. The paper, published in Nature, provides new insights into the nature and variability of mitochondrial DNA sequences, and has implications for cancer biomarker development and forensic analysis.
Human cells can house hundreds of mitochondria, each containing up to 10 copies of presumed identical mitochondrial DNA. Bert Vogelstein and colleagues show that these copies are often not identical, and can vary dramatically from tissue to tissue within individuals. The study shows that our tissues contain a mix of mitochondrial genotypes, cautioning the value of forensic tests that exclude identity on the basis of a mismatch between mitochondrial DNA isolated two different tissue types (for example, sperm vs hair).
Bert Vogelstein (Howard Hughes Medical Institute, Baltimore, MD, USA)
Abstract available online.
(C) Nature press release.
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