Worker survival and egg production depending on the diet

Aging is associated with diverse molecular processes such as oxidative
damage, a decrease in immunocompetence, or an increase in epigenetic
abnormalities, mutations, and inflammations. Many of these processes are
linked to nutrient-sensing signaling pathways, suggesting that diet plays
a critical role in the aging process. In fact, the protein content in the
diet can affect both longevity and fecundity, but often in opposite
directions. In many solitary organisms, protein-rich diets dramatically
shorten lifespan but increase egg production. We used the ant Temnothorax
rugatulus to investigate the effect of the protein-to-carbohydrate ratio
in the diet on the survival and fecundity of fertile workers. We fed
colonies either a moderately high-carbohydrate or high-protein diet (1:2
and 2:1 respectively) and monitored worker survival and egg production
over nine weeks. The protein-rich diet did not alter the ability of
workers to lay eggs, but reduced worker survival, suggesting that
consuming large amounts of protein may shorten the lifespan in
fertile ant workers without promoting reproduction. Our study shows for
the first time that a protein-rich diet reduces the overall fitness of
fertile workers.