Mice, rats and zebrafish will no longer be bred for medical research at one of the world’s leading genetics institutes

A row has broken out among scientists over the decision by one of the world’s leading genetics laboratories – the Sanger Institute in Cambridgeshire – to close its animal breeding facility.

The Wellcome Trust, which runs the institute, has decided that the £30m animal laboratory, where mice, rats and zebrafish are bred for medical experiments, should be shut within the next three years. It was set up 12 years ago and employs 70 staff. The institute – which played a leading role in the first sequencing of the human genome – says its scientists are now using fewer and fewer animals in their research.

“Our science strategy is changing. It is as simple as that,” Jeremy Farrar, director of the Wellcome Trust, told the Observer. “New laboratory techniques have recently been developed which mean we simply do not need the numbers of animals that were once required for our experiments. We still need animals for our research, but not as many as in the past.”

As a result, the Sanger is seeking a partner organisation that would provide an animal experimentation service for its scientists, though this will no longer be based at the institute.

But this approach has been questioned by other scientists. “I think that the Sanger decision is disappointing,” said geneticist Professor Ian Jackson, of Edinburgh University. “At present, techniques such as cell cultures cannot tell the whole story of what a mutated gene does. You need to observe what it does inside a living animal. A gene can have an unexpected impact in some organs.”

The use of animals in scientific experiments has been a cause of controversy for decades and has been opposed – sometimes violently – by activists. However, scientists have defended the practice on the grounds that it has led to significant medical advances, from the development of penicillin to the creation of drugs to treat breast cancer.

The crucial point is that animals like mice may have very different appearances from that of humans, but they share virtually the same set of genes. Almost every gene found in a mouse so far has been found in a closely related form in a human.

And the importance of this genetic similarity underpins the worries that some scientists have about the Sanger decision. “We recently carried out experiments on mice in which we had disabled a random set of their genes and found several that, unexpectedly, affected their hearing,” said Professor Karen Steel, of King’s College London, whose current research focuses on deafness.

“These have been shown to affect humans in a similar way, which greatly helps us to understand deafness in men and women. You simply cannot make discoveries like that in a culture dish, and it is premature to move in that direction,” she said.

Sanger scientists said they did not intend to halt all animal experiments but merely planned to carry out fewer procedures on living creatures. The development of techniques such as cells grown in culture and the creation of organoids, miniaturised versions of animal or human organs – such as the pancreas and kidney – now made it possible to think about reducing numbers of animal experiments, they argued.

“This is a positive story,” Farrar said. “The development of tissue culture and organoids has opened up the possibility of reducing animal experiments. It won’t take away the need to carry out all such procedures, but it should help to keep them down.”

This point was backed by Professor Mike Stratton, director of the Sanger. “This has been a difficult decision,” he said. “However, we believe it is the best way to continue to deliver science and make discoveries that impact on human health.”