Experimental Protocol for Using Drosophila As an Invertebrate Model System for Toxicity Testing in the Laboratory

Summary

In this paper, we provide a detailed protocol for exposing species in the genus Drosophila to pollutants with the goal of studying the impact of exposure on a range of phenotypic outputs at different developmental stages and for more than one generation.

Abstract

Emergent properties and external factors (population-level and ecosystem-level interactions, in particular) play important roles in mediating ecologically-important endpoints, though they are rarely considered in toxicological studies. D. melanogaster is emerging as a toxicology model for the behavioral, neurological, and genetic impacts of toxicants, to name a few. More importantly, species in the genus Drosophila can be utilized as a model system for an integrative framework approach to incorporate emergent properties and answer ecologically-relevant questions in toxicology research. The aim of this paper is to provide a protocol for exposing species in the genus Drosophila to pollutants to be used as a model system for a range of phenotypic outputs and ecologically-relevant questions. More specifically, this protocol can be used to 1) link multiple biological levels of organization and understand the impact of toxicants on both individual- and population-level fitness; 2) test the impact of toxicants at different stages of developmental exposure; 3) test multigenerational and evolutionary implications of pollutants; and 4) test multiple contaminants and stressors simultaneously.

Introduction

Every year, approximately 1,000 new chemicals are introduced by the chemical industry^1,2; however, the environmental impacts of only a small percentage of these chemicals are tested before distribution^2,3. Although large-scale catastrophes are uncommon, sublethal and chronic exposure to a large variety of pollutants are widespread in both humans and wildlife^4,5. The historical focus of ecotoxicology and environmental toxicology was to test lethality, single chemical exposure, acute exposure, an....

Protocol

The following protocol is an experimental protocol used to rear species in the Drosophila genus on contaminated medium when oral ingestion of a toxin is appropriate; other forms of exposure are possible using the Drosophila model^11,15,16,26. The methods described in this protocol have been previously described by Hirsch et al.¹⁹ and Peterson et al.^23,24,25.

1. Set ....

Results

By orally exposing Drosophila to a contaminant(s) throughout development, various toxicological questions can be tested by exposing Drosophila at different levels of biological organization. This section presents representative results obtained using this protocol in previously published papers^23,24. In particular, this protocol was previously used to evaluate the accumulation, elimination and sequestration of le.......

Discussion

Drosophila melanogaster has been established as a powerful model for a range of biological processes due to the extensive conservation of genes and pathways between D. melanogaster and humans^13,14. For the same reasons that it's a powerful model for medical science, Drosophila has emerged as a suitable model system to study the impact of anthropogenic pollution on a range of toxicological endpoints. Several laboratories are successf.......

Materials

List of materials used in this article

Name	Company	Catalog Number	Comments
Carolina Biological Instant Drosophila Medium Formula 4-24	Carolina Biological	173204
Drosophila vials, Narrow (PS), Polystyrene, Superbulk, 1000 vials/unit	Genessee Scientific	32-116SB	Used to store flies
Flugs Closures for vials and bottles, Narrow plastic vials	Genessee Scientific	49-102	Used to store flies
Cardboard trays, trays only, narrow	Genessee Scientific	32-124	Used to organize populations of flies
Cardboard trays, dividers only, narrow	Genessee Scientific	32-126	Used to organize populations of flies
Thermo Scientific Nalgene Square Wide-Mouth HDPE Bottles with Closure	Fischer Scientific	03-312D	Useful for storage of contaminants
Thermo Scientific Nalgene Color-Coded LDPE Wash Bottles	Fischer Scientific	03-409-17C	Useful for storage of contaminants
Eppendorf Repeater M4 Manual Handheld Pipette Dispenser	Fischer Scientific	14-287-150	Used to prepare medium
Combitips Advanced Pipetter Tips - Standard, Eppendorf Quality Tips	Fischer Scientific	13-683-708	Used to prepare medium
Flypad, Standard Size (8.1 X 11.6cm)	Genessee Scientific	59-114	Used to anesthetize flies
Flystuff foot valve	Genessee Scientific	59-121	Used to anesthetize flies
Tubing, green (1 continguous foot/unit)	Genessee Scientific	59-124G	Used to anesthetize flies
Mineral Oil, Light, White, High Purity Grade, 500 mL HDPE Bottle	VWR	97064-130	Used to make a morgue
Glass Erlenmeyer Flask Set - 3 Sizes - 50, 150 and 250ml, Karter Scientific 214U2	Walmart	Not applicable	Used to make a morgue
BGSET5 Glass Beaker Set Of 5	Walmart
Inbred or wildtype line of Drosophila	Bloomington Drosophila Stock Center at Indiana University		https://bdsc.indiana.edu
Wild popultions of Drosophila	UC San Diego Drosophila Stock Center		https://stockcenter.ucsd.edu/info/welcome.php