Lab mouse genome isn't simple

The patterns of variation between genomes of standard laboratory inbred mice are not as simple as generally believed, according to a team reporting in PNAS. The results suggest that researchers will be forced to use other methods in quantitative trait loci (QTL) mapping, as gene identification will become "not impossible, but more challenging," said Richard Mott, who led the study with Jonathan Flint at the Wellcome Trust Centre for Human Genetics, Oxford.

"Inbred strains are great in the sense that they're completely homozygous," said Mott. But laboratory mice were bred originally by amateur scientists who used anything they could catch, said Mott. "They weren't created, generally speaking, for genetic research. The question is, if you look at the genomes of these inbred strains in detail, how do they differ?"

Mott and his team sequenced about 12% of a 4.8-megabase region known to contain a QTL affecting anxiety in each of ...