Light Spot Assay: A Method to Investigate Drosophila Phototactic Behavior
Transcrição
– Begin by selecting a third instar larva, the largest of the larval forms, from the culture medium, and wash it with water para remove any food. Since the larval eyes, or Bolwig organs, are located de the upper front of the larva, place the larva de the center of an agar plate with the light source above the animal. Turn off the room light and allow the larva para acclimate para the dark.
Since the larva is barely detectable de a light spot made by visible light, turn on infrared LED lights para illuminate the animal for the camera. Wait until the animal begins crawling straight para control for its path. And then rotate the plate so that the larva crawls directly toward the light spot. Record the animal crawling into the light and then away from the light spot. This light-avoidance tactic helps larvae avoid predators by burrowing into food.
In the following example, we will perform the light spot assay para test the ability of different genetic strains of Drosophila larvae para escape light.
– Before introducing the larva para the imaging setup, acquire a short video of the light position, and nome the unfiltered control background video “lightarea1”. Place the filter back on the camera lens, and turn on a light far from the experimental device at as low a setting as possible while still allowing the larvae para be clearly observed. Use a spoon para remove some larvae from the culture medium, and gently select a third instar larva.
Wash the larva de distilled water, and place the larva de the center of the agar plate. Gently remove any excess water from the larva, and turn off the room light. Allow the larva para acclimate for two minutes de the dark environment before turning on the infrared LED light. The following light-avoidance behavior experiment needs para be carried out de the dark. For the convenience of demonstration, we filmed de the bright light.
Gently brush the larva para the center of the plate. When the larva begins para crawl straight, rotate the plate para make the larva head towards the light spot. Click Capture, Setup, and Video Capture para select the save path. And click Start Recording para record. Allow the lava para crawl toward, enter, and leave the light spot until it is nearly out of the field of view, then click Stop Recording.
Move the filter away from the camera, and acquire a short video of the position of the light spot. Then nome the post as a unfiltered video, “lightarea2”, and compare this video with the “lightarea1” video para ensure that the light spot position is not changed.
