This technique, published in Nature Protocols, provides a more humane way to study the impacts of environmental hazards on freshwater fish, whilst reducing the number needed for experiments.
Professor Christer Hogstrand, King’s College London, said: “Whole-animal studies can use millions of fish worldwide each year, and therefore efforts are focusing on refining, reducing and replacing (3Rs) these numbers.”
In the study, researchers found that using just two fish can produce between 40-72 ‘mini gills’.
Doctor Nic Bury, King’s College London, said: “In this technique, gill cells from one fish are placed onto inserts and grown for a day. The next day, a second seed of gill cells from another fish are placed on top of the first seed – this is known as a double-seeded-insert technique (DSI).”
These ‘mini gills’ can be used as an alternative for toxicology testing, bioaccumulation studies and environmental water quality monitoring, as the researchers discovered that they can tolerate freshwater in the laboratory, as well as river water taken in the field.
Doctor Nic Bury, King’s College London, said: “The next step is to further develop this technique to extend its tolerance as the cell cultures can only withstand water exposure of up to 48 hours. By extending this period, the ‘mini gills’ could be used for longer-term studies.”
The study was funded by the Biotechnology and Biological Sciences Research Council (BBSRC) and the National Centre for the Replacement, Refinement and Reduction of Animals in Research (NC3Rs).
