UK researchers have discovered that a gene called DAF-16, that is known to be involved in the process of ageing, strongly influences the rate of ageing and average lifespan in nematode worms, and suggest the finding could open new doors for altering ageing, immunity and stress resilience in humans, since we have the same gene, as do many other animals.
You can read about the study, which was funded by the Biotechnology and Biological Sciences Research Council (BBSRC) and led by Dr Robin May, of the School of Biosciences at the University of Birmingham, in PLoS ONE, where a paper on it has been available online since 1st April.
May said in a statement that all organisms undergo ageing, but at very different rates.
“We know that, even between closely related species, average lifespans can vary enormously,” said May, explaining that he and his team wanted to find out how normal ageing is regulated by genes and what other traits might be influenced by the same genes, for instance immunity.
“To do that, we looked at a gene that we already knew to be involved in the ageing process, called DAF-16, to see how it may determine the different rates of ageing in different species,” he added.
DAF-16 plays a role in the “dauer” stage of development in nematode worms and affects lifespan and reproduction. It encodes a protein that belongs to a class known as “forkhead transcription factors” that control the expression of other genes. It is active in most cells and is similar to a series of genes in humans known as FOXO1, FOXO3, FOXO4 and FOXO6.
For the study, May and his colleagues compared the longevity of 4 species of nematode worm (Caenorhabditis elegans, Caenorhabditis briggsae, Caenorhabditis remanei and Caenorhabditis brenneri) and how this related to DAF-16 expression.
They found, for example, that DAF-16 expression is 12 times stronger in C. remanei, which also has a longer lifespan, than C. elegans.
When they investigated the worms’ resistance to stress and immunity, by exposing them to high temperatures, heavy metals and various bacterial and fungal diseases, they found that in general, the species with the highest DAF-16 expression lived longer, had increased resistance to stress and better immunity against infection.
There was one exception: in the case of infection with Salmonella, they found little difference among the four species.
May said that DAF-16 belongs to a group genes that drivs the biology of ageing, immunity and response to environmental stress.
“The fact that subtle differences in DAF-16 between species seem to have such an impact on ageing and health is very interesting and may explain how differences in lifespan and related traits have arisen during evolution,” he added.
May and colleagues are now investigating how DAF-16 controls genes to balance the varying needs of an organism’s immune system over time.
Chief Executive of BBSRC Professor Douglas Kell said:
“Research using model organisms that uncovers the biology underpinning ageing gives us the opportunity to understand some of the mechanisms that determine how humans age in a healthy, or at least normal, way.”
He said that research like this helps us better understand ageing and develop ways to improve the quality of life for older people, such as coping with illness, daily living tasks and recalling memories.
“Phenotypic Covariance of Longevity, Immunity and Stress Resistance in the Caenorhabditis Nematodes.”
Francis R. G. Amrit, Claudia M. L. Boehnisch, Robin C. May.
PLoS ONE, 2010, 5(4): e9978, Published online 01 Apr 2010.
Written by: Catharine Paddock, PhD