Gut See

Shining a light on microscopic life is only half the battle to seeing what’s going on. Fluorescent proteins (FPs) are often used like bright beacons inside cells and tissues, but looking down through a microscope can be like staring at street lights from a plane – blurry and indistinct. These fruit fly intestines have been genetically engineered to produce a special type of photoactivatable FP, switched on and off with lasers. A technique called RESOLFT uses fast on/off switching to picture small areas of fluorescence one after another. A bit like turning a string of lights on one at a time, a sharp pattern emerges behind the glare – here individual tubules in the gut’s cytoskeleton stand out like flames in a fire. Examining the fruit fly’s digestive system tells us a lot about how our own guts evolved, but these techniques are being used to spot details inside human cells, too.

Written by John Ankers

• Image from work by Sebastian Schnorrenberg and colleagues
• Max Planck Institute for Biophysical Chemistry, Germany
• Image originally published under a Creative Commons Licence (BY 4.0)
• Published in eLife, June 2016