By switching off the ageing gene DAF-2 roundworm Caenorhabditis lived more than twice as long as normal, which is the equivalent of a human living up to 200 years. This gene controls IGF-1 liver signalling proteins found on the membranes of cells.
IGF-1 hormones control an organism’s growth, reproduction, and longevity; reducing its activity has been shown to increase lifespan in many animals, as such the team allowed the worms to develop and reach maturity before knocking down DAF-2; as expected the worms lived more than two times longer when IGF-1 signalling was reduced.
“It is thought we age due to an accumulation of unrepaired cellular damage in the body, and ageing is a result of energy trade offs between growth, reproduction, and survival… switching off certain gene functions in adulthood can increase longevity without a reproduction cost… understanding these processes is important to understanding the evolution of ageing, and for programmes aimed at lifespan extension….” explains Dr. Alexei Maklakov.
“This study is important as we are killing two birds with one stone because we are improving the health and longevity of the parents which in turn is improving the Darwinian fitness of their offspring… to establish which of the processes is more prevalent across the tree of life will improve understandings of how and why we age fundamental to improving quality of life in an increasingly long lived society”
Findings support emerging views of suboptimal gene expression in adulthood being at the heart of ageing; results show natural selection optimises gene expression early in life but it is not strong enough to continue later in life causing problems, and changes the idea of ageing invariably being linked to energy allocation between survival and reproduction.
