DOI: 10.5061/dryad.4mw6m90cs
title: Data from: Metabolic and immunological responses of Drosophila melanogaster to dietary restriction and bacterial infection differ substantially between genotypes in a population

description: 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.
description: Two isofemale (homogenous) lines of <em>Drosophila
 melanogaster </em>were selected for use in the present study based
 on emergence percentage (survivorship) and referred to as  A and B. Line A
 was the population that produced the lowest emergence rate while line B
 was the population that produced the highest emergence rate of the eight
 isofemale lines tested. A heterogeneous population (experimental) was
 created by mixing the eight isofemale lines altogether. To assess the
 effects of protein-restricted diet and/or infection by  Pectobacterium
 carotovorum on the response of the populations A and B (genotypes) and the
 heterogeneous population (Exp), first instar
 <em>Drosophila</em> larvae were allowed to develop under four
 environmental conditions. These conditions were uninfected+standard diet,
 uninfected+restricted diet, infected+standard diet, and
 infected+restricted diet. Parameters such as survivorship, lipid and
 protein contents, phenol-oxidase activity, and antibacterial rate were
 assessed following exposure. Moreover, the extent of plasticity among
 isofemale lines (genotypes) and the heterogeneous population, was
 calculated using the relative distance plasticity index (RDPI).
 Survivorship was observed as the number of emerged adults out of ten
 larvae. The lipid and protein contents, phenol-oxidase activity and
 antibacterial rate were determined spectrophotometrically in the whole
 body homogenate of <em>D. melanogaster</em>
 larvae.  
description: # Metabolic and immunological responses of Drosophila melanogaster to
 dietary restriction and bacterial infection differ substantially between
 genotypes in a population
 [https://doi.org/10.5061/dryad.4mw6m90cs](https://doi.org/10.5061/dryad.4mw6m90cs) ## Description of the data and file structure Two isofemale (homogenous) lines were selected for use in the present study based on emergence percentage (survivorship) and referred to as A and B. Line A was the population A that produced the lowest egg-to-adult survival rate, while line B was the population that produced the highest egg-to-adult survival rate of eight isofemale lines tested, as reported in Elkayal et al. (2016). A heterogeneous population (experimental) was created by mixing the eight isofemale lines altogether as described in The Drosophila Synthetic Population Resource (DSPR, 2021). To assess the effects of protein-restricted diet and/or infection by Pectobacterium carotovorum on the response of the populations A and B (genotypes) and the heterogeneous population (Exp), first instar Drosophila larvae were allowed to develop under four environmental conditions. These conditions were uninfected+standard diet, uninfected+restricted diet, infected+standard diet, and infected+restricted diet. Parameters such as survivorship, protein and lipid contents, phenol-oxidase activity, and antibacterial rate were assessed following exposure. Moreover, the extent of plasticity among isofemale lines (genotypes) and the heterogeneous population, was calculated using the relative distance plasticity index (RDPI) as described in (Valladares et al., 2006). ### Files and variables #### File: Dataset.xls **Description:** we measured the survivorship, lipid and protein contents, phenol-oxidase specific activity and antibacterial activity of Drosophila melanogaster third-instar larvae after exposure to 4 environments. These conditions were as follows: i) standard medium in the absence of Pectobacterium carotovorum (uninfected standard), ii) restricted dietary medium in the absence of P. carotovorum (uninfected restricted), iii) P. carotovorum + standard medium (infected standard), and iv) P. carotovorum + restricted dietary medium (infected restricted). Survivorship was observed as the number of emerged adults out of ten larvae. The lipid and protein contents, phenol-oxidase activity and antibacterial rate were determined spectrophotometrically in the whole body homogenate of D. melanogaster larvae. ##### Variables * Population (categorical): we used three populations two homogenous populations (A represents the unfit population and B represents the fit population in terms of percentage emergence) as well as a heterogeneous population (Exp). * Diet: the populations were exposed to two different diet regimens (standard and protein-restricted diets). * Treatment: the population were exposed to two different treatment conditions called (control and infection with bacteria). - Environment (categorical): by combining treatment conditions and diet, we have exposed the populations to 4 environmental conditions (i) standard medium in the absence of Pectobacterium carotovorum (uninfected standard), ii) restricted dietary medium in the absence of P. carotovorum (uninfected restricted), iii) P. carotovorum + standard medium (infected standard), and iv) P. carotovorum + restricted dietary medium (infected restricted). - Survivor: number of emerged adults/replicate after exposure of D. melanogaster larvae to the environmental conditions tested. * Total: Number of D. melanogaster larvae tested in each replicate of the emergence experiment. - Emergence (proportion): number of emerged adults/replicate out of 10 D. melanogaster larvae tested. - trans_emergence: transformation of emergence = (Arcsin(Square root(emergence)). - Lipid content (continuous): the content of lipid in D. melanogaster larval homogenate (mg/g body), was measured using a spectrophotometer after 4-day exposure to the environments. - Protein contents (mg/g body) (continuous): the content of protein in D. melanogaster larval homogenate (mg/g body) was measured using a spectrophotometer after 4-day exposure of the environments. - Phenol-oxidase specific activity (continuous): It was measured in D. melanogaster larval homogenate after 4-day exposure to the environments. One unit is the amount of enzyme required to increase the absorbance at 490 nm by 0.001 min−1 divided by the protein content (mg) determined in the sample (Unit/mg.min) - Antibacterial rate (proportion): It was measured in D. melanogaster larval homogenate after 4-day exposure to the environments. The antibacterial rate was expressed as a rate, number of cell forming units in the P. carotovorum suspension incubated for 2h with whole-body homogenate of Drosophila larvae (95:5 v/v) in relation to the control measurement. The control contains Ringer’s solution instead of whole-body homogenate. - trans_antibacterial rate : transformation of antibacterial rate = (Arcsin(Square root(antibacterial rate)). #### File: plasticity\_index.xlsx **Description:** Three variables (two independent variables: genotype and environment) and one dependent variable (emergence, protein content, lipid content, Phenol-oxidase specific activity or antibacterial rate). we used 7 replicates for the emergence experiment and 5 replicates for the other experiments. ##### Variables * Environment_1 or environment_2 (categorical): it represents the type of environmental conditions, in which we exposed the different genotypes. It contains 4 categories: (i) control condition with standard medium (control standard), ii) control condition with restricted dietary medium (control restricted), iii) infection with P. carotovorum + standard medium (infected standard), and iv) infection with P. carotovorum + restricted dietary medium (infected restricted). * Genotype (categorical): we used three categories, two homogenous populations (A represents the unfit genotype and B represents the fit genotype in terms of percentage emergence) as well as one heterogeneous population (Exp). * Survivorship_1 and survivorship_2 (proportion): number of emerged adults/replicate out of 10 D. melanogaster larvae tested in different environments (environment_1 or environment_2). * Protein content_1 and protein content_2 (continuous): the content of protein in D. melanogaster larval homogenate (mg/g body) was measured using a spectrophotometer after 4-day exposure to different environments (environment_1 or environment_2). * Lipid content_1 and lipid content_2 (continuous): the content of lipid in D. melanogaster larval homogenate (mg/g body), was measured using a spectrophotometer after 4-day exposure to the environments (environment_1 or environment_2). * Phenoloxidase specific activity_1 and phenoloxidase specific activity_2 (continuous): It was measured in D. melanogaster larval homogenate (Unit/mg.min) after 4-day exposure to the different environments (environment_1 or environment_2). * Antibacterial rate_1 and antibacterial rate_2 (proportion): It was measured in D. melanogaster larval homogenate after 4-day exposure to different environments (environment_1 or environment_2). The antibacterial rate was expressed as a rate, number of cell forming units in the P. carotovorum suspension incubated for 2h with whole-body homogenate of Drosophila larvae (95:5 v/v) in relation to the control measurement. The control contains Ringer’s solution instead of whole-body homogenate. * Changing environment: by comparing environment_1 and environment_2, there is always one condition that is considered different, diet restriction or infection condition. * Fixed environment: by comparing environment_1 and environment_2, there is always one condition that is considered fixed: control and infection conditions, as well as standard and restricted diets. * Index (proportion): relative distance plasticity index (RDPI), the difference between the trait values of the same genotype in different environments divided by their sum. * Mean = Average of indices of one genotype at one changing environment. * SD = Standard deviation of the indices of one genotype in one changing environment. * M = Average of the indices of one genotype in diet restriction or infection condition. * sd = Standard deviation of the indices of one genotype in diet restriction or infection condition. * Mean_total = Average of the indices of one genotype across all environments. * sd_total = standard deviation of the indices of one genotype across all environments. ## Code/software There is missing data. Blank cells include n/a. ## Access information Other publicly accessible locations of the data: * No Data was derived from the following sources: * No