Glow cats with jellyfish genes help advance HIV treatment

Green glowing cats have been created by gene scientists working on the Aids virus.

The animals had their DNA modified with a gene from a fluorescent jellyfish. Placed under blue light, their fur, claws and whiskers emit a green glow.

The purpose of the study was to show how a natural protein that prevents macaque monkeys developing Aids can do the same in cats.

Scientists in the US used the jellyfish gene to track the gene for the protein. Both were inserted into the DNA of adult tabby cats, which gave birth to luminous kittens.

Cats are susceptible to their own version of the HIV virus that triggers Aids, called feline immunodeficiency virus, or FIV.

Normally, the immune systems of cats and humans are overwhelmed by the viruses.

But macaque monkeys possess “restriction factor” proteins that can stop the viruses invading immune cells.

When cats were genetically engineered to produce one of these factors, TRIMcyp, FIV replication was reduced.

Two male cats and one female with the genes were born and survived. The male passed the genes down to kittens of his own, which emitted a weaker glow.

Eric Poeschla, from the Mayo Clinic in Rochester, New York state, who led the study, reported in the journal Nature Methods: “One of the best things about this biomedical research is that it is aimed at benefiting both human and feline health. It can help cats as much as people.”

There are no plans to place restriction factor genes from monkeys into humans – or to create glowing humans. But it is hoped the research will help scientists looking for new ways to combat HIV and Aids understand how the restriction factor proteins work.

British experts welcomed the research, but cautioned against assuming immediate human applications.

Professor Helen Sang and Professor Bruce Whitelaw of the Roslin Institute at Edinburgh University, said: “This report on a novel method for producing genetically-modified cats is an advance on previous studies using cloning in cats.

“This report describes the use of viral vectors to introduce genes into oocytes, a method that has already been shown to be very efficient in a range of other mammalian species, including pigs and sheep. The method described here is shown to be relatively effective in cats, reducing the number of experimental animals that are needed, although the embryological technologies are not yet as successful as in livestock.”

Dr Robin Lovell-Badge, from the Medical Research Council National Institute For Medical Research, said: “When carrying out research with animals, it is important to consider the most appropriate species for the questions to be addressed, and to adopt methods that are the least harmful, are efficient, and are likely to generate valuable data. The work on transgenic cats … satisfies all these requirements.”

Although the green fluorescent protein gene produced “dramatic pictures” it was important for studying the transfer of a gene that may confer resistance against Aids viruses, said Prof Lovell-Badge.

He added: “Cats are one of the few animal species that are normally susceptible to such viruses, and indeed they are subject to a pandemic, with symptoms as devastating to cats as they are to humans. Understanding how to confer resistance is therefore, as the authors point out, of equal importance to cat health as it is to human health.”

However, the experiments were strongly opposed by animal welfare campaigners.

Dr Ned Buyukmihci, veterinary adviser for the British Union for the Abolition of Vivisection, said: “Gene modification can result in substantial, unintended abnormalities; it is likely that many of the cats in earlier studies suffered greatly or were killed in order for researchers to get to this point.

“This type of research serves only to continue our reliance on scientifically flawed animal-based research. Science should instead be progressing in the area of non-animal alternatives.”