Data from: Metabolic and immunological responses of Drosophila melanogaster to dietary restriction and bacterial infection differ substantially between genotypes in a population

To respond to changing environmental conditions, a population may either
shift towards better-adapted genotypes or adapt on an individual level.
The present work aimed to quantify the relevance of these two processes by
comparing the responses of defined Drosophila populations to different
stressors. To do this, we infected two homogeneous populations (isofemale
lines), which differ significantly in fitness, and a synthetic
heterogeneous population with a specific pathogen and/or exposed them to
food restriction. Pectobacterium carotovorum was used to infect Drosophila
larvae either fed standard or protein-restricted diets. In particular, the
two homogeneous groups, which diverged in their fitness, showed
considerable differences in all parameters assessed (survivorship, protein
and lipid contents, phenol-oxidase activity, and antibacterial rate).
Under fully nutritious conditions, larvae of the homogeneous population
with low fitness exhibited lower survivorship and protein levels, as well
as higher phenol-oxidase activity and antibacterial rate compared with the
fitter population. A protein-restricted diet and bacterial infection
provoked a decrease in survivorship, and antibacterial rate in most
populations. Bacterial infection elicited an opposite response in protein
and lipid content in both isofemale lines tested. Interestingly, the
heterogeneous population showed a complex response pattern. The response
of the heterogeneous population followed the fit genotype in terms of
survival and antibacterial activity but followed the unfit genotype in
terms of phenol-oxidase activity. In conclusion, our results show that
defined genotypes exhibit highly divergent responses to varying stressors
that are difficult to predict. Furthermore, the responses of heterogeneous
populations do not follow a fixed pattern showing a very high degree of
plasticity and differences between different genotypes.