NEW YORK, March 31 (GenomeWeb News) - The draft genome sequence of the brown Norway laboratory rat, Rattus norvegicus, has been completed by the Rat Genome Sequencing project Consortium, the consortium said today.
This is the third mammalian genome to be sequenced to a high degree of quality, and published in a major scientific journal. Efforts are underway to compare this genome to that of the other two sequenced genomes, the mouse and human.
The Rat Genome Sequencing consortium was led by the Human Genome Sequencing Center at Baylor College of Medicine in Houston, in conjunction with the National Human Genome Research Institute and the National Heart, Lung, and Blood Institute, the major funders for the project.
"The sequencing of the rat genome constitutes another major milestone in our effort to expand our knowledge of the human genome," said NHGRI director Francis Collins in a statement. "As we build upon the foundation laid by the Human Genome Project, it's become clear that comparing the human genome with those of other organisms is the most powerful tool available to understand the complex genomic components involved in human health and disease."
The sequence draft, which covers 90 percent of the rat genome, is being published in the 1 April issue of Nature. Thirty other articles analyzing the genome are being published simultaneously in the April issue of Genome Research.
According to the Nature article, the rat genome, at 2.75 Gb, is smaller than the human genome (2.9 Gb), but larger than the mouse genome, which is 2.6 Gb. All three, however, have similar numbers of genes. Additionally, orthologs were found in the rat genome for all human disease-associated genes. In total, about a billion nucleotides, or 40 percent of the rat genome, align orthologously to the human and mouse genome, and about 30 percent of the rat genome aligns only with mouse.
Additionally, genes found in rat but not mouse include ones encoding for pheromone production, immunity, chemosensation, detoxification and proteolysis.
Data for the Rat Genome Sequencing Project was generated by the Baylor team, with Celera Genomics, Genome Therapeutics (and later Agencourt Bioscience), the British Columbia Cancer Agency Genome Sciences Center, the Institute for Genomic Research; the University of Utah, the Medical College of Wisconsin, the Childrens Hospital of Oakland Research Institute, and Max-Delbruck-Center for Molecular Medicine in Berlin.
The sequencing of the rat genome involved both whole genome shotgun and BAC clone sequencing, and the genome was assembled using Atlas assembly software.
After the genome was assembled, a team of 20 groups in six countries performed the analysis, relying on gene and protein predictions from the EMBL-EBI and Sanger Institute Ensembl Project.
The Baylor group is now working on sequencing projects for the Bovine and Rhesus macaque genome projects.