What do zebrafish have to do with human health? More than you’d expect.

These tiny, transparent creatures are giving scientists big insights into rare genetic conditions like mitochondrial DNA depletion syndromes (MDDS).

People with MDDS have faulty genes that stop their cells from making energy. There’s no cure yet – and testing treatments in humans is risky. So, researchers turn to models and zebrafish are ideal.

Zebrafish share over 70% of their genes with humans. They develop quickly and scientists can watch their cells in real time.

Between 2018 and 2019, Lily funded research into using zebrafish to test new treatments for MDDS. Researchers created zebrafish with the same genetic mutations found in people with MDDS. These fish showed the same symptoms as patients – difficulty swimming, high lactate levels and reduced mitochondrial DNA.

Tiny fish, big breakthroughs

Then came a breakthrough. A treatment called deoxynucleosides, which is like giving extra DNA building blocks, helped the fish recover: their DNA improved, lactate levels dropped and they began to swim normally again.

Learn more about the project from our Research Manager, Maria, and hear from Dr Ben Munro as he explains the impact of the funding and how it supported this work:

While this Lily-funded research has now ended, the project was so exciting that it’s expanded beyond just one lab and is now part of a larger, international effort, accelerating progress across Europe.

Prof Rita Horvath, lead of the Cambridge University team who worked on the project, said: “This research improved knowledge in the field of mitochondrial disease by exploring the effect of nucleoside supplementation in mitochondrial DNA depletion syndromes.”

Thanks to zebrafish, we’re getting closer to real treatments for people living with mitochondrial disease.