Why a fruit fly is for life

The potential for using worms or fruit flies to replace protected animals such as mice, dogs and primates in scientific testing is the latest focus for the UK Government agency that funds advances into the replacement and reduction of animals in research.

The National Centre for the Replacement, Refinement and Reduction of Animals in Research (NC3Rs) has announced the 2008 winners of £2.6 million in funding for its flagship scheme to advance knowledge and application of the 3Rs (see listings opposite). It has now also thrown open the doors for the scheme's 2009 round - and has confirmed that a "priority area" will be for work towards "replacing animals protected under the Animals (Scientific Procedures) Act 1986 with invertebrate models".

"We want to encourage scientists who are doing research with invertebrates to think about whether their work could be relevant to replacing some vertebrate models that are currently being used in disease research," explained Harriet Warburton, programme manager for research funding at the NC3Rs.

The priority area comes against a backdrop of rising numbers of vertebrates being used in experiments (3.2 million procedures were carried out in 2007).

This year's pot for the NC3Rs scheme is initially worth £2.5 million, but no specific amount has been "ring-fenced" for the priority area. The priority area has been agreed with the Biotechnology and Biological Sciences Research Council, which will welcome applications for support for fundamental research that addresses the issue.

Dr Warburton said the reason for the call was that the UK had "real strength" in the area of invertebrate biology and there was "a lot of potential" to apply invertebrate models where vertebrate models are currently being used. "It is not something that has been done before and it is something both the NC3Rs and the BBSRC want to encourage," she said.

The two most common invertebrate models used in scientific studies are the nematode worm (C. elegans) and the drosophila fruit fly. A range of human diseases from neurological disorders to heart disease are studied using these models.

The idea behind the priority designation is to take examples where a current vertebrate model is not working well and see whether an invertebrate model would work better. "Could the nematode worm or drosophila fruit fly be useful to answer some of the questions currently being done in mice models?" asked Dr Warburton. Proposals could involve other types of switching and did not have to be limited to swapping worms and fruit flies for mice, she said.

The use of invertebrates is considered to be a "replacement" technique because, bar a certain species of octopus which is considered highly intelligent, they are not covered by the animal scientific procedures Act. Invertebrates, said Dr Warburton, have "much lower potential" to feel pain and suffer.

She said that, aside from a reduction in the use of protected animals, "clear scientific, financial and time benefits" could also be derived from switching to invertebrate models. "Invertebrates have shorter lifespans which mean they can be produced more quickly, easily and cheaply."

Those interested in applying for the funding need to submit an application either to the NC3Rs or the BBSRC. Applications that directly relate to replacing a currently used vertebrate with an invertebrate, such as toxicity testing, drug discovery or disease studies, will be funded by the NC3Rs while fundamental research into the potential for replacement will be BBSRC funded. Expressions of interest for the priority area close on 17 October and the two agencies will work together to ensure that proposals are considered correctly.

Dr Warburton said it was important for researchers to be clear about what was being replaced, what the severity of the current procedures are and what the scientific benefits of switching to a new model might be. She encouraged researchers to get in touch to discuss proposals. "We want to be sure that what's being proposed will actually be a useful replacement ... collaborations between people who are using invertebrates and those working on diseases that would benefit from a new model would obviously be viewed favourably."

Cahir O'Kane, a reader in genetics at the University of Cambridge who uses drosophila fruit flies to study human diseases, welcomed the designation and said it would raise awareness of the issue. "Quite a lot of people haven't appreciated the possibility fully," he said. But he cautioned that it was important for the funding not to detract from what made sense scientifically: "There are some things for which you just cannot replace mammalian models."

zoe.corbyn@tsleducation.com

www.nc3rs.org.uk/invertebratepriority.