Officials at the National Institute of Environmental Health Sciences, part of the National Institutes of Health, say they plan to use the animals immediately to help determine how different organisms react to environmental toxins.

"These data allow researchers to compare the genetic makeup of one mouse strain to another and perform the necessary genetic analyses to determine why some individuals might be more susceptible to disease than others," said David Schwartz, NIEHS director. "This puts us one step closer to understanding individual susceptibility to environmental toxins in humans. We also hope that pharmaceutical companies developing new treatments for environmental diseases will find these data a valuable resource."

Most of the mapping was done at Perlegen Sciences Inc. in Mountain View, Calif., using the oligonucleotide array technology used to discover common DNA variations in the human genome.

The researchers used C57BL/6J -- the first mouse strain to undergo DNA sequencing -- as their standard reference for the other 14 strains, some of which were wild and some of which were raised in the laboratory.

The report appears in the July 29 issue of the journal Nature.