Frog's immune system is key in fight against killer virus

Feb 27, 2009

(PhysOrg.com) -- Scientists from Queen Mary, University of London have discovered how changes to a frog's immune system may be the key to beating a viral infection which is devastating frog populations across the UK.

Communities of common frogs (Rana temporaria) are being struck down by a foreign virus which is estimated to be killing tens of thousands of frogs in the UK each year. When it strikes garden ponds, the surrounding lawn becomes strewn with dead frogs, some with skin ulcers so severe they reduce limbs to stumps, others with internal bleeding. The virus, called Ranavirus, has invaded the home counties around London, and is now spreading north and west.

Writing in the journal PLoS One, Dr Amber Teacher describes how the frogs' immune system has responded to the virus. Working with her fellow scientists at Queen Mary, University of London and experts at the Institute of Zoology, she studied ponds where Ranavirus deaths are occurring year after year, and consistently found changes to a gene called the MHC, which codes for a major part of the frog's immune system.

Dr Teacher explains: "It seems, as Darwin would have predicted, that the plucky surviving frogs have passed on to their descendants an immune system which is better tuned to the new threat."

Teacher also found that the frogs' immune systems are simpler than many other animals, including humans, who have several MHC genes doing a similar job. She adds: "This discovery has helped identify the point in our evolutionary history when this multiplication of genes occurred. With luck, even the frog's simpler system will be sufficient to win their battle".

It is too early to determine if the adaptation in the frogs' immune response will be enough to save them from the virus. Her colleague Professor Richard Nichols, from Queen Mary's School of Biological and Chemical Sciences added: "From a scientific point of view we could learn as much about the fight against viruses, whether the frogs succumb or they don't; but from a personal point of view I hope these changes are the first signs that the frogs getting the upper hand over the virus."

More information: ‘Evidence for Directional Selection at a Novel Major Histocompatibility Class I Marker in Wild Common Frogs (Rana temporaria) Exposed to a Viral Pathogen’ will be published online in PLoS ONE on Wednesday, 25 February.

Source: Queen Mary, University of London

Explore further: Research shows impact of BMR on brain size in fish

Related Stories

Stinky frogs are a treasure trove of antibiotic substances

Nov 30, 2011

Some of the nastiest smelling creatures on Earth have skin that produces the greatest known variety of anti-bacterial substances that hold promise for becoming new weapons in the battle against antibiotic-resistant ...

Humans, sharks share immune-system feature

Sep 30, 2011

A central element of the immune system has remained constant through more than 400 million years of evolution, according to new research at National Jewish Health. In the September 29, 2011, online version ...

Amphibian communities collapse in wake of viral outbreak

Oct 16, 2014

Two closely related viruses that have been introduced to northern Spain in recent years have already led to the collapse of three different species of amphibian—the common midwife toad, the common toad, ...

Recommended for you

Research shows impact of BMR on brain size in fish

22 hours ago

A commonly used term to describe nutritional needs and energy expenditure in humans – basal metabolic rate – could also be used to give insight into brain size of ocean fish, according to new research by Dr Teresa Iglesias ...

Why do animals fight members of other species?

Apr 23, 2015

Why do animals fight with members of other species? A nine-year study by UCLA biologists says the reason often has to do with "obtaining priority access to females" in the area.

Dolphins use extra energy to communicate in noisy waters

Apr 23, 2015

Dolphins that raise their voices to be heard in noisy environments expend extra energy in doing so, according to new research that for the first time measures the biological costs to marine mammals of trying ...

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.