DOI: 10.5061/dryad.1g1jwsttk
title: Post-eclosion temperature effects on insect cuticular hydrocarbon profiles

description: The insect cuticle is the interface between internal homeostasis and the
 often harsh external environment. Cuticular hydrocarbons (CHCs) are key
 constituents of this hard cuticle and are associated with a variety of
 functions including stress response and communication. CHC production and
 deposition on the insect cuticle vary among natural populations and are
 affected by developmental temperature; however, little is known about CHC
 plasticity in response to the environment experienced following eclosion,
 during which time the insect cuticle undergoes several crucial changes. We
 targeted this crucial phase and studied post-eclosion temperature effects
 on CHC profiles in two natural populations of Drosophila melanogaster. A
 forty-eight hour post-eclosion exposure to three different temperatures
 (18, 25, & 30 °C) significantly affected CHCs in both ancestral
 African and more recently derived North American populations of D.
 melanogaster. A clear shift from shorter to longer CHCs chain-length was
 observed with increasing temperature, and the effects of post-eclosion
 temperature varied across populations and between sexes. The quantitative
 differences in CHCs were associated with variation in desiccation
 tolerance among populations. Surprisingly, we did not detect any
 significant differences in water loss rate between African and North
 American populations. Overall, our results demonstrate strong genetic and
 plasticity effects in CHC profiles in response to environmental
 temperatures experienced at the adult stage as well as associations with
 desiccation tolerance, which is crucial in understanding holometabolan
 responses to stress.
description: Body Mass Data: Body weight data was collected
 in the groups of five flies. The wet weight and dry weight data are given
 in miligrams. To obtain dry weight flies were dried at 50 degree
 centrigrade overnight. The wet mass, dry mass, and water content values
 were used to generate residuals for ANOVA analysis of desiccation
 tolerance.  Cuticular Hydrocarbon
 Data: Hydrocarbons were extracted in hexane before running
 through gas chromatography column. Data file contains raw data (retention
 time). Peak areas of the GC chromatograms corresponding to individual CHCs
 were converted into relative proportions of the sum of CHC peak areas. The
 relative data was arcsine transformed and the overall quantitative
 variability among samples and treatments visualized using principal
 component analysis (PCA) performed in Statistica 8.0.
 Desiccation Assay: Flies in the groups of five
 were used for desiccation assay. To measure desiccation tolerance
 desiccating environemnt was created in the tube (using Silica gel). Data
 contains hourly dead flies number. We used LT<sub>100</sub>
 data. We ran a mixed model ANOVA where population cages were nested within
 geographic source population. Respirometry
 Data (Water Loss Rate): Water-loss rate (WLR) was measured using
 flow-through respirometry. Flies in the groups were placed in a glass
 chamber where dry air was allowed to get in and outlet was connected with
 a humidity sensor. Water-loss rate was calculated from water vapor
 released by flies into the air stream. We ran a mixed model ANOVA where
 lines were nested within geographic source population.
description: The data has been provided in excel files. There are no missing
 values. Data could easily be accessed and analyzed for various other
 purposes.