Wednesday, July 6, 2011

Naked mole rat's genome 'blueprint' revealed

African Naked mole rat baby Photo
The industrious but unlovely naked mole rat is the latest creature to have its genome sequenced by scientists.
A genetic blueprint for this bizarre-looking rodent could help researchers understand why it is so long-lived.
Naked mole rats are also of interest to scientists because they appear to have some resistance to cancer.
A team from the University of Liverpool, UK, led the project and have made the "first draft" of the genome available online for other researchers.
Dr Joao Pedro Magalhaes, the Liverpool-based biologist who led the study, explained that he became interested in naked mole rats when he discovered how long they lived.
"Bigger animals tend to live longer, but the naked mole rat is an exception to that rule," he told BBC Nature.
"It can live over 30 years, which is very impressive for an animal that's smaller than a rat. Rats live for just four years."
Dr Magalhaes worked with researchers from Queen Mary, University of London, which is home to the UK's only naked mole rat colony.
The animals are native to the deserts of East Africa, where they dig their tunnels using their impressive teeth.
Unlike true rats, mole rats form a distinct group of rodents that are adapted to live underground.
Unique physical traits allow naked mole rats to survive in these harsh, underground environments for so many years. And the genetic secrets of those traits are contained in the mole rats' DNA.
Previous research has shown that the small wrinkled rodents have very little or no pain sensation in their skin and a low metabolic rate that allows them to live with limited oxygen.
The animals are also resistant to many diseases, particularly cancer.
Naked mole rat (image:
Naked Mole Rat Picture
"I think that's the most interesting thing about them from a biomedical perspective," said Dr Magalhaes.
"To date, there have been no reported deaths of cancer, and there are [teams] around the world that have kept and studied naked mole rats for decades."
The gene sequencing technology the team employed used chemical scissors to snip out chunks of the long strands of DNA code that make up the animal's genome. This technique allows these shorter sections of code to be read and jigsawed back together into the complete genome.
Dr Chris Faulkes, who studies naked mole rats at Queen Mary, University of London, was keen to help with this project. The genome, he explained, was a valuable research tool.
"We're interested in how the animals evolved their amazing social behaviour," he told BBC Nature.
"They live in groups of up to 300 animals and each group has a [reproductively active] queen who can 'switch off' the reproduction in other animals."
These findings will allow Dr Faulkes and his team to find any features of the rats' brains that might drive these unusual social bonds and behaviour.
Dr Magalhaes says that the team now has a "blueprint" for the naked mole rat that will allow "much more sophisticated studies of the animals".
"You can start to look, for example, at the DNA repair systems in naked mole rats, and find out if they are different from mice, which have a much shorter lifespan," he said.
"It's a first step to uncovering the mysteries of this creature's remarkable longevity and its resistance to diseases."
The mole rats spend their entire lives underground