Project Details
Projekt
The fecundity/longevity trade-off in a clonal ant
Applicant
Abel Bernadou, Ph.D.
Subject Area
Evolution, Anthropology
Term
from 2018 to 2022
Project identifier
Deutsche Forschungsgemeinschaft (DFG) - Project number 261675780
In many solitary organisms longevity is negatively correlated with fecundity because of resource trade-offs. Queens of social insects are a notable exception to this rule. Reproductive individuals appear to avoid or even reverse this fundamental trade-off: they have extended longevity and high egg-laying capacities. However, in most advanced social insects, reproductives and non-reproductives differ tremendously in ontogeny, morphology, physiology, behavior and resource availability, which may affect the interrelation between fecundity and longevity. Clonal ants, such as Platythyrea punctata, are therefore suitable models to study the trade-off without these confounding traits: reproductives and non-reproductives of clonal ants are mostly identical. Nevertheless, reproductives live significantly longer than all non-egg-laying workers.During the 1st funding phase, we documented a number of factors that influence longevity and fecundity, e.g., nutritional manipulations (fat content and protein to carbohydrate ratios), removal of eggs, and oxidative stress. In addition, a transcriptome analysis - between reproductives and non-reproductives - matched these previous results and revealed several genes that are known to respond to oxidative stress, to be involved in nutrient signalling pathways, related to metabolism, or link environmental stimuli with phenotypic changes. Overall, our results point to the role of nutrition as well as to IIS/TOR pathways as important mediators in the regulation of fecundity and longevity. Although several interactions among these pathways are known, many “connections” among genes and how they contribute to this apparent remolding of the trade-off remain unclear. In the 2nd funding phase, our main aim is now to gain a deeper understanding of these interrelations and how reproduction and diet affect lifespan and gene expression changes. To do so, we will manipulate (i) the costs of reproduction, (ii) diets, and (iii) putative genes involved in the fecundity/longevity trade-off via RNAi. Thereafter we will measure the consequences of these manipulations for longevity, fecundity, oxidative stress, and immune responses. Finally, based on the most promising treatments, we will compare via transcriptome studies gene and pathway modifications. Our project will allow us, by manipulating (in-)directly candidate genes and by testing their effect at a phenotypic level, to elucidate their roles in the trade-off. It will also complement well other projects within the Research Unit 2281 by allowing us to compare the pathways involved between the different model organisms and to generalize hypotheses about the regulation of reproduction and longevity in social insects.
DFG Programme
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