WASHINGTON, March 31 (UPI) -- U.S.-led researchers said Tuesday they have sequenced the genome of the Brown Norway rat, only the third mammal to be sequenced, after humans and mice.
"Today we gather to honor the rat -- something we don't often do," said Dr. Francis Collins, of the National Human Genome Research Institute, at a news conference.
Rats are closely related to humans, sharing nearly 90 percent of their genes, Collins said.
Nearly a million scientific papers since 1966 have used laboratory rats as models, but no gene model has been available until now, said Howard Jacob of the Medical College of Wisconsin's Human and Molecular Genetics Center.
The researchers said they actually mapped only 90 percent of the rat's genome because the remaining 10 percent could cost far more and might not yield the same wealth of information, said Richard Gibbs of Baylor College of Medicine's Human Genome Sequencing Center.
At about $110 million, the project's cost was roughly one-third of the human genome, Gibbs said. It was the first to use a faster method that could map as many as 20 mammals within the next several years.