lab rat’s code cracked

To mice and men, add the common lab rat to the creatures whose genomes — or genetic blueprints — have been sequenced and decoded. A large international team of researchers known as the Rat Genome Sequencing Project Consortium reported their draft of the brown Norway rat’s genetic map in the April 1 issue of Nature. The researchers found that the rat genome is slightly smaller than the human, and slightly larger than the mouse, but that all three share about 25,000 to 30,000 genes. The rat genome should help shed light on the complicated genetic components of human physiology and illness, since almost all human genes linked to disease have been found to have counterparts in the rat, confirming its use as an excellent model for medical research. The team also found that rats, unlike mice, have genes that help them deal with toxins, and that evolutionary changes have occurred at a faster rate in rodents than in primates, suggesting that their genes may be more dynamic than our own.

This news brief appeared in the Discoveries column of the Boston Globe’s Health/Science section on 4/06/2004.