Follow That Fish

Development is a delicate process, shrouded in mystery as much as it is in darkness – how can we follow what we can’t see? Fluorescent sensors are often used like beacons to pinpoint and measure early microscopic life, but they usually don’t last long – broken apart quickly inside the natural tissues. Yet in the lower of these two zebrafish (Danio rerio) artificial light was first switched on four months ago. Using a modified form of the UAS-GAL4 system, researchers create a long-term fluorescent sensor. Activated by a blast of heat, the green fluorescence is self-sustaining – recycled by way of feedback loops. With further genetic tweaks, the team were able to follow their sensor – and trace the lineage of cells in the fish’s developing tissues from one day after fertilisation into adulthood. While zebrafish are a common biological model for human development, this new tool could well be modified for use in species even closer to us.

Written by John Ankers

John Ankers

Writer

A former researcher in systems biology, John is now an online biology tutor and professional coach supporting the wellbeing of scientists and NHS professionals. He's writing, too, of course.

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• Image from work by Yanfeng Li and colleagues
• Institute of Developmental Biology and Regenerative Medicine, Southwest University, Chongqing, China
• Image originally published with a Creative Commons Attribution 4.0 International (CC BY 4.0)
• Published in Development, March 2025