Until now, opinions concerning the concrete “how and when?” of the inheritance of mitochondrial mutations were largely divided. Doctor Christoph Freyer and his international research team developed a new model and found answers: Intra-family differences in the degree of mutation of the mitochondrial genes are largely established before the mother herself is born.
The major part of a living organism’s genetic blueprint is held in the cell’s nucleus in the form of DNA. However, a cell’s mitochondria carry their own hereditary information as mtDNA. Mutations in the mtDNA can strongly affect health, since mitochondria play a central role in energy supply in the cell. Mutations are exclusively passed on via maternal mtDNA.
The new model developed by Freyer and his team through the research of mouse cells analyses the ratio of mutated to non-mutated genes over the different phases of the hereditary process: within germ cells, immature germ cells of the next generation and the following generation of mice. His findings show that mutated genes are not selected out by the female germ line. So whether and o what exten mutant genes can be transmitted to the next generation is decided when the future mother is still herself an embryo.
Freyer observed that mice mitochondria are able to compensate potential defects caused by mutations. This provides further insight into the hereditary process mechanisms underlying mitochondrial disease. Freyer hopes that this compensation can be stimulated by medical means. Therapies could be tested to prevent the hereditary transmission of mtDNA mutations.
MEDICA.de; Source: Max Planck Institute for Biology of Aging