Gene activity glows in the eyes
Scientists from the USA and the UK have created flies with glowing eyes and developed a system that allows you to track their movement simultaneously with the brightness of the glow. The new technique allows you to observe the work of genes in real time and on a freely moving animal. A detailed description of the method is presented in the freely distributed journal BMC Biotechnology (Simultaneous tracking of fly movement and gene expression using GFP).
To solve one of the most important tasks in neuroscience - understanding the relationship between gene expression and behavior - biologists used a green fluorescent protein.
The gene of interest to the researchers (in total, scientists studied three different genes associated with the development of the nervous system and aging) was associated with the fluorescent protein gene so that they were expressed simultaneously and in equal amounts. After that, a special installation with blue backlight, light filters and a video camera was used to track the animal.
(In the image of Kevin Edwards Laboratory, University of Illinois - the eye of a transgenic fly with a fluorescent protein.)
Contrary to popular misconception, the fluorescent protein, for the discovery of which the Nobel Prize in Chemistry was awarded this year, does not glow by itself. Its molecules absorb light with more energy (blue, so the experimenters used blue LEDs for illumination) and emit light with less energy (green). Blue light does not pass through the filters installed on the video cameras, and therefore transgenic flies are visible only thanks to the fluorescent tags, and not the light falling on them. These marks were used to determine the position of insects, which made it possible to study their activity. The brightness of the labels indicated the intensity of gene expression, and thus scientists were able to look at the relationship of behavior with the work of the genome.
Of the three genes studied, one, PAX6, which is associated with the development of the eyes and nervous system, was also responsible for regulating the level of activity during the day. Two more genes worked in the last hours of the drosophila's life and naturally led to a decrease in the animal's activity. As the authors themselves point out, when analyzing such long-term processes (the life cycle of drosophila lasts several tens of days), the new method turns out to be especially valuable and eliminates the need to carry out many separate measurements.