Image:A schematic of an ant colony’s social network of exchange. 

The role of metabolic division of labour in determining lifespan

Supervisor: Prof Adria LeBoeuf

Life thrives on collaboration – this extends to the molecular scale, where life is fueled by the chemical processes collectively called metabolism. Microorganisms exchange nutrients through cross-feeding, and multicellular organisms are made up of cells with different metabolic roles and needs. These collaborations rely on metabolic division of labour. 

Social insects provide an ideal study system to understand metabolic division of labour for two reasons: 1. They subvert the classic life-history trade-off between longevity and fecundity with long-lived highly fertile queens and small short-lived sterile workers, and 2. Many ant colonies engage in frequent mouth-to-mouth social exchanges of experimentally accessible fluids that contain endogenously produced materials. These exchanges are so frequent that they form a social circulatory system that distributes material across the colony, allowing metabolic costs to be allocated locally while benefits are distributed across the collective. 

Our lab has done ample groundwork on this system in charactering the proteins that are socially transferred between individuals, where they are produced, when and by whom. This project addresses the role of metabolic division of labour in controlling lifespan – it has two parts. One will focus on tracking protein flow between individuals using stable-isotope proteomics and quantitative feeding measures. The second will quantify the metabolic costs of production for the producers and the longevity benefits for receivers using RNAi, artificial diets, and measurements of physiology, oxidative stress, and metabolic rate. 

Disentangling metabolic division of labour in ant colonies, where we can monitor exchanges easily, will allow us to better understand how some of our tissues/individuals lighten the load of others and possibly how to better extend life- and health-span.

References

Negroni & LeBoeuf. Metabolic division of labor in social insects. 2023 COIS https://doi.org/10.1016/j.cois.2023.101085

Hakala SM, Meurville MP, Stumpe M, LeBoeuf AC. 2021. Biomarkers in a socially exchanged fluid reflect colony maturity, behavior, and distributed metabolism. Elife 10. doi:10.7554/eLife.74005

Kramer BH, Nehring V, Buttstedt A, Heinze J, Korb J, Libbrecht R, Meusemann K, Paxton RJ, Séguret A, Schaub F and Bernadou A. (2021) Oxidative stress and senescence in social insects: a significant but inconsistent link? Philosophical Transactions of the Royal Society B, 376(1823), 20190732.