Because Iraq and politics are all fucked up today, I decided this will be Cool Science Day
Rat's 'life code' read by science
By Jonathan Amos
BBC News Online science staff
Scientists have decoded the rat genome, the biochemical instructions in the rodent's cells that guide the building and maintenance of the animal's body.
It is the third mammalian DNA sequence to be deciphered - humans and mice came first - and will be used by researchers to understand the causes of disease.
It should also give valuable insights into the evolution of all mammals.
…Of rodents and dogs
"If one looks at genes that are basically equivalent, then nine out of 10 are the same," said Professor Chris Ponting, from the UK Medical Research Council's Functional Genetics Unit, who worked on the project.
"The disease genes are nearly all within that 90% - they're conserved between rodents and humans. Therefore, in looking at the biology of human disease genes in rodents, it appears rodents make excellent models," he told BBC News Online.
Some families of genes, though, have been greatly expanded in the rat, including, perhaps not surprisingly, those associated with the ability to emit and sense smells.
There are significant distinctions, also, in the genes of the immune system.
Comparison of the rat code with those of the human and the mouse should allow a remarkable view of mammalian evolution.
The rat data shows about 40% of the modern mammalian genome derives from the last common mammalian ancestor that existed tens of millions of years ago. This "core" DNA encodes nearly all the genes and their regulatory signals, and accounts for the similarities among mammals, such as the basic body plan.
More details about the fundamental biochemistry and evolution of mammals will become apparent when scientists get to compare the human and the rodent codes with those of the soon-to-be finished chimp and dog genomes.
"What we know about the dog is that genetically speaking it is closer to humans than rodents, even though in terms of evolution it is further away," explained Professor Ponting.
"That's to say, the dog lineage split off from the human lineage before rodents - it's just that the rodents' DNA has mutated like crazy since then."
