Dietary zinc limitation dictates lifespan and reproduction trade-offs of Drosophila mothers
Dietary metal ions significantly influence the lifespan and reproduction of Drosophila females. In this study, we show that while the depletion of all metal ions from the diet adversely affects reproduction and lifespan, the absence of Zn alone negatively impacts reproduction without adversely altering maternal lifespan, indicating it can dictate resource reallocation between key fitness traits. Although our data show that flies sense varying dietary Zn levels, they apparently do not alter their feeding preferences to optimise egg production when faced with a choice between Zn- depleted or Zn- sufficient food, but they can choose to preferentially oviposit on Zn containing food, perhaps indicating a strategy to assure offspring survival. We also uncovered a role for the white gene in sustaining high levels of egg viability when Zn is diluted in the diet. These insights into the role of dietary metal ions, particularly Zn, point to a central role for these dietary micronutrients to indicate environmental quality and so govern trade-offs between lifespan and reproduction in flies.