Two new organisms sequenced

Researchers at the Wellcome Trust Sanger Institute and their collaborators have published the genome sequence of Schizosaccharomyces pombe (fission yeast) and completed sequencing of Mycobacterium bovis.

Analysis of the fission yeast genome sequence was published in February 2002 in Nature. Fission yeast has been studied genetically since the 1950s, and among single-celled organisms, it is second only to budding yeast (Saccharomyces cerevisiae) for the ease with which it can be genetically manipulated.

The availability of the annotated genome sequence will accelerate the organism's use in studies of basic cellular processes, particularly cell division. As such S. pombe is a valuable model organism for studies of cancer and other human diseases. More than 99.8 per cent of its genome is now in public domain databases, and all that sequence has been analysed for protein-coding capacity. S. pombe has become the second publicly available unicellular eukaryotic sequence, after S. cerevisiae. There are striking differences between S. pombe and S. cerevisiae genomes, and comparisons between the two organisms will shed important light on their respective biologies.

Sequencing of M. bovis, the bacterium that causes tuberculosis (TB) in cattle, has also been completed. M. bovis can also cause TB in a number of other species, including badgers and humans: although the risk is low, bovine TB can be passed to humans if they drink untreated (unpasteurized) milk from infected cows. The number of TB cases in both humans and cattle - and wild animals - has increased significantly around the world in recent years.

The M. bovis genome is very similar (99.9 per cent identical) to that of the human TB bacterium, Mycobacterium tuberculosis. Analysis of the TB and M. bovis genomes has revealed an unexpected evolutionary scenario for the development of these two pathogens. It had been thought that M. tuberculosis arose when M. bovis crossed the species barrier into humans after cattle began to be domesticated 10-15000 years ago. However, since the M. bovis genome is smaller than that of M. tuberculosis, it is more likely that humans gave tuberculosis to cattle, or that the two organisms evolved separately from a common ancestor.

Core analysis of the fission yeast genome was carried out by Val Wood, Rachel Lyne and Mike Lyne from the Wellcome Trust Sanger Institute, based on map data refined by Rhian Gwilliam. Dr Paul Nurse, Joint Director General of Cancer Research UK, and his team contributed specific analyses. Genome sequencing was carried out by a European consortium led by the Sanger Institute. Funding was provided by the European Commission and the Wellcome Trust.

The M. bovis genome was determined in a collaborative project between Dr Glyn Hewinson's team at the Veterinary Laboratories Agency, Dr Stewart Cole's team at the Pasteur Institute, Paris, and the Pathogen Genome Sequencing Unit at the Sanger Institute, led by Dr Bart Barrell. The project was funded by the Ministry of Agriculture, Fisheries and Food (now DEFRA), the Pasteur Institute and the Wellcome Trust.

External links

• Schizosaccharomyces pombe genome sequencing project at the Wellcome Trust Sanger Institute
• Mycobacterium bovis genome sequencing project at the Wellcome Trust Sanger Institute
• The genome sequence of Schizosaccharomyces pombe, Nature 415, 871-880 (21 February 2002)