December 18th, 2012
Digging Deeper into Nematode Longevity via Loss of Germ Cells
If you remove germ cells from nematode worms or flies they live longer. Researchers continue to investigate the mechanisms involved:
The gonad is well known to be important for reproduction but also affects animal life span. Removal of germ cells - the sperm and egg producing cells - increases longevity of the roundworm Caenorhabditis elegans. However, the underlying molecular mechanisms were a mystery. [The] roundworm Caenorhabditis elegans is a commonly used model organism in the field of ageing research. It develops from an egg to adult through four larval stages. These developmental stages are controlled by a developmental clock.[Researchers] used a laser to remove the germ cells. They found that the remaining gonadal cells trigger production of a steroid hormone called dafachronic acid. Dafachronic acid activates so-called microRNAs, which work as tiny molecular switches causing changes in gene expression that promote longevity. Interestingly, this same steroid hormone-microRNA switch was previously shown [to] be part of the developmental clock. Thus, the loss of the germ cells ultimately causes the worm to use developmental timers to put in motion a life-prolonging programme.