Data from: HIF-signaling in the prothoracic gland regulates growth and development in hypoxia but not normoxia in Drosophila
Data files
Sep 20, 2024 version files 79.97 KB
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Body_Size.csv
52.51 KB
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Developmental_Time.csv
9.29 KB
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Expression.csv
13.85 KB
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README.md
2.94 KB
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Survival.csv
845 B
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Western.csv
530 B
Abstract
The developmental regulation of body size is a fundamental life-history characteristic that in most animals is tied to the transition from juvenile to adult form. In holometabolous insects this transition is ostensibly initiated at the attainment of a critical weight in the final larval instar. It has been hypothesized that the size-sensing mechanism used to determine attainment of critical weight exploits oxygen limitation as a larvae grows beyond the oxygen-delivery capacity of its fixed tracheal system; that is, developmentally-induced cellular hypoxia initiates the synthesis of the molting hormone ecdysone by the prothoracic gland. We tested this hypothesis in Drosophila by assaying cellular hypoxia throughout the third-larval instar at 21 and 10 kPa O2, using the activity of the HIF-signalling pathway as a measure of hypoxia. While HIF-signalling was elevated at low levels of environmental O2 it did not markedly increase during development at either oxygen level, and was only suppressed by hyperoxia after feeding had ceased. Further, changes in HIF-signalling in the prothoracic gland alone did not alter body size or developmental time in a way that would be expected if cellular hypoxia in the prothoracic gland was part of the critical weight mechanism. Our data do show, however, that reduced HIF-signalling in the prothoracic gland decreases survival and retards development at 10 kPa O2, suggesting that prothoracic HIF-signaling is a necessary part of the beneficial plasticity mechanism that controls growth and development in response to low oxygen level.
README: Data from: HIF-signaling in the prothoracic gland regulates growth and development in hypoxia but not normoxia in Drosophila
https://doi.org/10.5061/dryad.gf1vhhmxm
Description of the data and file structure
The data were collected from Drosophila larvae and adults reared in hypoxia (10kPa O2), normoxia (21kPa O2), or hyperoxia (40kPa O2). Drosophila were either wildtype controls or had up- and down-regulated HIF signaling in the PG by knockdown of Hph and HIF-1α *expression, respectively, using phm-GAL4 to drive expression of *UAS-Hph.RNAi and UAS-HIF-1α.RNAi.
Files and variables
The archive comprises six files. An RMarkdown file (Analysis.rmd) of the annotated code used to conduct the analysis and five text files (.csv) of the data used in the analysis.
The data files are as follows:
- Expression.csv contains the gene expression data. Variables include which gene is being analyzed (gene), experimental treatment (treatment), age in hours from ecdysis to third instar as a categorical variable (age), age in hours from ecdysis to third instar as a continuous variable (agenum), copy number (copies), pooled age as a categorical variable (pooled), pooled age as a continuous variable (poolnum), oxygen level in percent as a categorical variable (ox), and oxygen level in percent as a continuous variable (oxnum).
- Westen.csv contains the western blot data assaying HIF-1α protein levels. Variables include age of larvae (time), oxygen level in precent (oxygen), and protein level (density and logdensity, unitless).
- Body Size.csv contains the body size data. Variables include cross (cross: fga/phm – knockdown of Hph; sima/phm – knockdown of HIF-1α), oxygen level in percent (o2), sex (sex), genotype (genotype: +/+, uas/+, gal4/+, uas/gal4), adult mass in mg (mass), and experimental type (type: control, exp).
- Developmental Time.csv contains the developmental time data. Variables include cross (uas: fga [Hph], sima [HIF-1α]), oxygen level in percent (o2), genotype (genotype: +/+, fga/+, sima/+, phm/+, fga/phm, sima/phm), total number of flies (total.flies), age in hours from oviposition (age), number of eclosed flies at each age (eclose), number of uneclosed flies at each age (not.eclose), and experimental type (type: control, exp).
- Survival.csv contains the survival data. Variables include cross (uas: fga [Hph], sima [HIF-1α]), oxygen level in percent (o2), total number of flies (total.flies), genotype (genotype: +/+, uas/+, gal4/+, uas/gal4), number of flies that eclose as adults (eclose), number of flies that do not eclose as adults (not.eclose), and experimental type (type: control, exp).
Code/software
The analysis can be conducted in R using RStudio (2022.07.1) and R (4.0.3). The R Markdown file contains the annotated script of all the analysis described in the paper.
Methods
The data include:
- Gene expression analysis of HIF-signaling genes in Drosophila melanogaster third-instar larvae reared at 10, 21 and 40 kPa O2.
- Western blot analysis of HIF-1α protein in Drosophila melanogaster third-instar larvae reared at 10, 21 and 40 kPa O2.
- Adult body size, developmental time, and survival of Drosophila melanogaster reared at 10 and 21 kPa O2, in which HIF-signaling in the prothoracic gland has been up- and down-regulated.