From an average of about 18 days in the lab, the longevity of C. elegans, the popular model organism for ageing research, increased 40–60% when researchers used a mutant that lacked the function of a particular gene (flr-4) and fed them a specific bacterial diet — E. coli strain H. The mutant worms fed another bacterial diet — E. coli strain O — did not show any increase in life span. Scientists use the term “diet-gene pairing” to describe such events. So far, only four gene-diet pairs that modulate longevity have been discovered using these worms. And researchers from the National Institute of Immunology (NII), New Delhi led by Arnab Mukhopadhyay have discovered the fifth such pair. The results were published in the journal PLOS Genetics. That longevity increases with reduced caloric or dietary restriction is well known. But in this study, there was increase in life span of the mutants even when there was no restriction on the quantity of food consumed. To find out the relation of flr-4 gene and dietary restriction, the researchers generated a condition where the mutant worms had reduced food intake. One would expect the dietary restriction in the mutants to cause an additive effect leading to further increase in life span. “But we did not see an additive effect. So the cellular module or mechanism by which food restriction increases lifespan overlaps with the mechanism by which flr-4 mutation increases longevity. This shows that organisms have evolved distinct as well as overlapping ways to evaluate both the quality and quantity of diet to regulate lifespan,” says Dr. Mukhopadhyay.
Source : https://www.thehindu.com/todays-paper/tp-features/tp-sci-tech-and-agri/mutant-worms-live-60-longer-on-specific-diet/article24959063.ece