PLoS Biol. 7, e1000112 (2009)

Humans and mice have slightly less in common than was previously thought, reveals the international Mouse Genome Sequencing Consortium.

The team produced a more complete Mus musculus genome by sequencing DNA fragments and linking them back to a physical map of the genome. Earlier efforts used an efficient approach known as whole-genome sequence and assembly, which does not require a physical map. This left many gaps owing to difficulty in assembling some regions, such as those containing repetitive DNA. Now researchers have filled more than 175,000 gaps and uncovered more than 139 million bases of overlooked DNA. Moreover, they identified more than 2,000 genes the sequences of which were missed or wrongly assembled before, more than half of which do not have an analogue in the human genome.

The results underscore the importance of complete genome sequences, and should lend more power to comparative studies in human biology, the authors suggest.