Nematodes are Probably Not Useful Models of Mitochondrial Aging

Mitochondria, the power plants of the cell, carry their own DNA, encoding a few proteins essential to mitochondrial operation. Mutational damage to these genes can result in broken mitochondria that take over cells and cause the export of oxidizing molecules, contributing to the progression of aging. Not all mitochondrial DNA damage is the same, however: point mutations versus deletion mutations, for example. Researchers have struggled to produce consistent data in mice and nematodes with increased levels of mitochondrial DNA damage of various sorts. Some mice engineered to have greater mutation rates in mitochondrial DNA exhibit accelerated aging, while others do not, with little sign of a coherent explanation as to why beyond the sentiment that short-lived species are not useful models in this case. The work here in nematodes, using radiation to produce mitochondrial DNA damage, should probably taken as more in the same vein. The researchers find no correlation between damage levels and life span, and this may well be because they are not introducing the right sort of mutational damage that occurs over the course of aging in longer-lived species. It is thought that deletion mutations, or other equally drastic damage, is necessary, for example. But nematodes do not accumulate such damage over the course of their very short lives. They may just be a very poor model for any consideration of the mitochondrial contribution to the aging process. The mitochondrial ...
Source: Fight Aging! - Category: Research Authors: Tags: Daily News Source Type: blogs