Mitochondria are cell organelles located within animal and human cells. They produce energy for the organism, possess their own genetic material - mitochondrial DNA (mtDNA) - and are transmitted exclusively by the mother. Depending on their activity and tasks, different numbers of mitochondria are present in a cell - usually a few hundred to a thousand per body cell.
Inherited mitochondrial disorders or so-called mitochondropathies occur in about one of 10,000 humans throughout the world. Diseases such as diabetes, stroke, cardiac defects, epilepsy, or muscle weakness may originate from mitochondrial defects. Inherited mitochondrial disorders have been incurable so far. Therefore, efforts are now being made to enable women with this disease to bear healthy children by means of nuclear transfer.
Mitochondria multiply at different rates
Jrg Burgstaller, a scientist and member of Gottfried Brem's research group at the Vetmeduni Vienna, has been working for several years on the genetics of mitochondria. It was known before that different types of mitochondria within a cell can proliferate at different rates. However, it was not known whether this is a singular phenomenon or if these cases occur more frequently.
Burgstaller investigated this in four newly bred mouse models which carried different mixtures of mitochondria whose DNA were related to each other to a differing extent.
This meant no health problem for the mice since all mtDNAs are were fully functional.
The outcome was: the more distantly two types of mitochondria within an egg cell were related, the more frequently a growth advantage was noted in favor of one of the two types of mitochondria. When two different mtDNAs were equally common in cells of an organ at the time of birth, one type was completely lost after a while. One mitochondria variant had thus achieved a growth advantage compared to the other variant and superseded th
|Contact: Joerg Burgstaller|
University of Veterinary Medicine -- Vienna