Published: 23-05-2013 00:00 | Updated: 30-10-2014 09:27

Spruce genome of importance for medical research

Swedish scientists have mapped the genome sequence of Norway spruce – a species with huge economic and ecological importance and the largest genome to ever be mapped. The genome is complex and seven times larger than that of humans. The findings, which are published in the journal Nature, are the result of method- and technique development that will also benefit medical research in the future.

This major research project has been led by Umeå Plant Science Centre (UPSC) and the Science for Life Laboratory (SciLifeLab) in Stockholm, a collaboration of Karolinska Institutet, the Royal Institute of Technology (KTH) and Stockholm University. The scientists have identified about 29,000 functional genes, marginally more than in humans. However, the genome of the spruce is still seven times larger than ours. According to the study, this genome obesity is caused by extensive repetitive DNA sequences, which have accumulated for several hundred million years of evolutionary history. Other plant and animal species have efficient mechanisms to eliminate such repetitive DNA, but these do not seem to operate as well in conifers.

The greatest challenge in the project has been to get the approximately 20 billion 'letters' found in spruce's genetic code into the correct order, rather than obtaining the actual DNA sequences. In order to handle the large amount of DNA sequences, the scientists had to customize computers and rewrite much of the software used in earlier similar studies. The recently established research facility SciLifeLab was of huge importance to this work.

"Through this joint venture, critical infrastructure has been built and the local expertise in modern sequencing technology has been further developed, which we will greatly benefit from also in medical research", says Björn Andersson, Professor of genome analysis at Karolinska Institutet and one of the study authors. "A side project of the study has been comparative sequencing of other conifers, which may prove to be of more immediate medical use. This is something that we are working on right now."

The project was mainly financed by the Knut and Alice Wallenberg Foundation. Additional funders have been the Swedish Research Council, the Swedish Governmental Agency for Innovation Systems, the Swedish Research Council for Environment, Agricultural Sciences and Spatial Planning, the Swedish foundation for Strategic Research, amongst others.

Publication

The Norway spruce genome sequence and conifer genome evolution.
Nystedt B, Street N, Wetterbom A, Zuccolo A, Lin Y, Scofield D, et al
Nature 2013 May;497(7451):579-84