An Adjustable High-Definition Imaging System for Behavioral Studies of Drosophila Adults

Summary

This protocol describes how to make a simple adult Drosophila behavior observation chamber, and how to take high-definition photographs/videos of the morphology or behavior of different types of fruit flies in the observation chamber through relatively simple and affordable methods.

Abstract

Drosophila melanogaster is a very powerful model in biological research, but a bad model for photography or videography. This paper describes a simple but effective method to observe and document the behavior or morphology of flies. Flies were placed in a translucent observation chamber c.a. Ø15 x 5mm (no food inside) or Ø15 x 12 mm (with an 8 mm-high piece of food inside). After covering with an ultraviolet (UV)/clear filter with high light transmittance, the chamber was placed under a 5-50x zoom stereo microscope, and mini light-emitting diode (LED) video lights were placed on both sides of the microscope to illuminate the chamber to obtain uniform, soft, bright, and nearly shadow-free light. Then, a compact digital camera with 3-5x optical zoom, which can record 1080 P high-definition or higher resolution video (at a frame rate of ≥30 fps), was connected to the eyepiece of microscope through a bracket, and photographs or videos were taken through the eyepiece. By adjusting the zoom knob of the zoom stereo microscope, it was very easy to track the flies and take panoramic or detailed close-up images as needed, while the camera recorded everything under the microscope. Because the flies can stay at any position in the chamber, they can be observed and recorded from all directions. The photographs or videos taken are of good image quality. This method can be used both for scientific research and teaching.

Introduction

Drosophila melanogaster is an outstanding model in biological research; however, it is a bad model for photography or videography, as it is too small for a camera or a camcorder and too large for a compound microscope¹. Despite excellent research described in the literature, most studies have only provided blurred, unclear images, rather than clear and sharp photographs with clear detail that illustrate the fly behavior being described. Moreover, although fly behaviors have been extensively studied (e.g., courtship and fighting), most of these papers have used illustrations to explain their research to readers.

Protocol

1. Construction of the observing/documenting system

NOTE: The materials needed to construct the fly behavior observing/documenting system are shown in Figure 1, and the completed system is shown in Figure 2. The protocol to construct the system and how to use it are described below.

1. Make a fly behavior observation chambe.......

Discussion

Light is at the very heart of photography and videography and is the decisive factor for obtaining high-quality images¹⁶. Here, two LED video lights with adjustable brightness and color temperature were used as illuminators, and a translucent material was selected to make the FBOC. The LED light panels on both sides provided enough brightness, and the translucent material softened and scattered light, eventually producing uniform, soft, and bright light to illuminate the flies in the FBOC, without.......

Materials

Name	Company	Catalog Number	Comments
compact camera, Nikon P310	Nikon		3-5x optical zoom, cam record 1080 P HD video
ethylamine foam			60 mm x 60 mm x 15 mm
Food Blue No 1		CAS 3844-45-9
mini LED lights and transformer	GODOX	LED-P120	have 5000-5600 K color temperature
small container (e.g. bottle cap)			about Ø 15 mm x 20 mm
UV / Clear filter			high-quality UV/Clear filter with high transmittance, 30-40 mm
zoom stereo microscope			5-50x zoom