Genetic effects are often context-dependent, with the same genotype differentially affecting phenotypes across environments, life stages, and sexes. We used an environmental manipulation designed to increase energy demand during development to investigate energy demand as a general physiological explanation for context-dependent effects of mutations, particularly for those mutations that affect metabolism. We found that increasing the period during which Drosophila larvae are active during development phenocopies a temperature-dependent developmental delay in a mitochondrial-nuclear genotype with disrupted metabolism. This result indicates that the context-dependent fitness effects of this genotype are not specific to the effects of temperature and may result generally from variation in energy demand. The effects of this genotype also differ across life stages and between the sexes. Metabolic rates are disrupted by this genetic interaction in growing larvae, but not in adults; and reproduction of females, but not males, is compromised by this genetic interaction. These patterns are consistent with a model where context-dependent genotype-phenotype relationships may generally arise from differences in energy demand experienced by individuals across environments, life stages, and sexes.
development time data
File 1: devtime.xlsx
5 data sheets
Eclose16_LD.txt
Eclose16_LL.txt
Eclose22_LL.txt
Eclose22_LD.txt
Eclose25_LD.txt
Rows: each row represents a single adult that eclosed on a given date with a particular development time in days (“EcloseDay”)
Columns:
Date — date vial was scored for progeny;
Mito — mtDNA genotype;
Nuc — nuclear genotype;
Temp — rearing temperature;
Light — photoperiod; 12,12 (LD) or 24,0 (LL);
Vial — unique identifier for each vial;
EcloseDay — days until eclosion;
devtime.xlsx
metabolic rate data
File 2: metrate.xlsx
4 data sheets
MRdat_Group1616.txt
MRdat_Group2525.txt
MRdat_Group1625.txt
MRdat_Group2516.txt
Rows: each row represents a measure of average VCO2 from a chamber containing 10 adult flies
Columns
date — date of measurement;
run — unique run of the respirometry system;
rep — each chamber was sampled twice during the run;
line — (mtDNA);nuclear genotype;
mtDNA — mtDNA genotype;
nuclear — nuclear genotype;
tdev - development rearing temperature in C;
tmeasure - temperature in C at which metabolic rate was measured;
sex;
CO2 — average rate of CO2 production;
CO2.se — standard error of this average;
mass — mass of 10 flies in chamber;
MassMeasured — the initial mass of 10 flies corrected for any flies lost during the experiment (total mass - mean mass * number of flies lost);
Act1 — the median absolute difference of the squared activity signal;
Act2 — the standard error of the squared activity signal
metrate.xlsx
reproduction data
File 3: reproduction.xlsx
datasheet: mitofert.txt
Rows: each row represents a single male’s number of offspring sired across three females
Columns
mtDNA — mtDNA genotype;
nuclear — nuclear genotype;
genotype — mtDNA;nuclear genotype;
male — replicate male ID;
females — number of females who survived and produced offspring;
total — the sum of offspring for each male across the three females;
totalper — total divided by the number of females;
exp — block A or B
datasheet: mitofecund.txt
Rows: each row represents the number of eggs laid by each female (original data are reported in Meiklejohn et al. (2013) PLoS Genet 9:e1003238)
Columns
mtDNA — mtDNA genotype;
nuclear — nuclear genotype;
genotype — mtDNA.nuclear genotype;
female — female ID number;
day1-day10 — egg counts each day;
total — summed egg counts across all days
reproduction.xlsx