title: The CApillary FEeder Assay Measures Food Intake in Drosophila melanogaster.
abstract: For most animals, feeding is an essential behavior for securing survival, and it influences development, locomotion, health and reproduction. Ingestion of the right type and quantity of food therefore has a major influence on quality of life. Research on feeding behavior focuses on the underlying processes that ensure actual feeding and unravels the role of factors regulating internal energy homeostasis and the neuronal bases of decision-making. The model organism Drosophila melanogaster, with its great variety of genetically traceable tools for labeling and manipulating single neurons, allows mapping of neuronal networks and identification of molecular signaling cascades involved in the regulation of food intake. This report demonstrates the CApillary FEeder assay (CAFE) and shows how to measure food intake in a group of flies for time spans ranging from hours to days. This easy-to-use assay consists of glass capillaries filled with liquid food that flies can freely access and feed on. Food consumption in the assay is accurately determined using simple measurement tools. Herein we describe step-by-step the method from setup to successful execution of the CAFE assay, and provide practical examples to analyze the food intake of a group of flies under controlled conditions. The reader is guided through possible limitations of the assay, and advantages and disadvantages of the method compared to other feeding assays in D. melanogaster are evaluated.
authors.affiliation: Institute of Zoology, Albertus-Magnus University of Cologne; sdiegelm@uni-koeln.de.
authors.forename: Soeren
authors.initials: S
authors.lastname: Diegelmann
authors.affiliation: Institute of Zoology, Albertus-Magnus University of Cologne.
authors.forename: Annika
authors.initials: A
authors.lastname: Jansen
authors.affiliation: Institute of Zoology, Albertus-Magnus University of Cologne; Department of Veterinary Biomedical Sciences, Western College of Veterinary Medicine, University of Saskatchewan.
authors.forename: Shreyas
authors.initials: S
authors.lastname: Jois
authors.affiliation: Institute of Zoology, Albertus-Magnus University of Cologne.
authors.forename: Katharina
authors.initials: K
authors.lastname: Kastenholz
authors.affiliation: Institute of Zoology, Albertus-Magnus University of Cologne.
authors.forename: Laura
authors.initials: L
authors.lastname: Velo Escarcena
authors.affiliation: Institute of Zoology, Albertus-Magnus University of Cologne.
authors.forename: Nicole
authors.initials: N
authors.lastname: Strudthoff
authors.affiliation: Institute of Zoology, Albertus-Magnus University of Cologne; henrike.scholz@uni-koeln.de.
authors.forename: Henrike
authors.initials: H
authors.lastname: Scholz
mesh_terms: D000818:Animals; D001522:Behavior, Animal; D001681:Biological Assay; D003124:Colorimetry; D004331:Drosophila melanogaster / Q000502:physiology*; D004435:Eating / Q000502:physiology*; D005247:Feeding Behavior / Q000502:physiology*; D005260:Female; D008297:Male