Starvation during L4-larval stage induces longevity in Caenorhabditis elegans

Abstract

The effects of experiencing starvation during adolescence, during which significant physical growth and sexual maturation occurs, on adulthood have remained largely unknown. In addition, the influence of nutritional status during adolescence on brain maturation and function are discussed on the viewpoints of young people’s mental, psychology and behavior. In order to gain knowledge about the effects of starvation on adolescence, we starved the model organism Caenorhabditis elegans during its fourth larval stage (L4), and the lifespan and expression of genes in insulin/IGF-1 pathway, which is crucial to regulate lifespan, of the resulting adult worms were analyzed. The worm’s gonadogenesis and spermatogenesis take place during the L4 stage, making the stage a possible equivalence to human puberty. We found that worms which experienced starvation during their L4 stage had significantly longer lifespan, especially in the latter half of their lifespan, namely the aged worms lived longer. The relative expression of daf-16 in the insulin/IGF-1 pathway increased as worms become old, suggesting that the insulin/IGF-1 pathway functioned to extend lifespan in old worms. It was also observed that the locomotor ability (mobility) of L4-starved adult worms decreased. In addition, expression of ser-4, serotonin receptor, which was reported to be involved in lifespan regulation in worms, increased gradually toward late lifespan, suggesting that effect of experiencing starvation during L4 stage may also be regulated by serotonin. Our data posed a possibility that also in human, hunger and nutritional deficiencies in adolescence may affect health and activity in later adulthood.