Arabidopsis lyrata(Image by OutiSavolainen, University of Oulu, Finland)
Arabidopsis thaliana is a small flowering plant often used as a model system by researchers. As part of the 2006 Community Sequencing Program portfolio, the DOE JGI selected A. thaliana’s close relative A. lyrata for sequencing. By comparing their genomes and the genomes of other, related species, researchers could gain insight into plant genetics, specifically how they respond to disease and environmental stress.
In a report published online April 10, 2011 in Nature Genetics, a team of researchers led by collaborators Magnus Nordborg and DetlefWeigel and including JGI’s Igor Grigoriev and Jeremy Schmutz at the HudsonAlpha Institute for Biotechnology compared the sequences of A. thaliana and A. lyrata.
Representing the research team, Nordborg also discussed the differences between these two plant genomes during the recent JGI User Meeting in a talk entitled “How to lose half your genome in 10 million years and live to tell the tale.”
“An exciting opportunity to understand what drives differences in genome size over shorter time scales is offered by the genus Arabidopsis in the Brassicaceae family,” the researchers noted in their paper comparing the two species that diverged 10 million years ago.
Sequenced using the Sanger sequencing platform, the high-quality 207-million base pair reference genome of A. lyrata was found to be nearly twice as large as that of A. thaliana. The model plant also had fewer chromosomes and roughly 17 percent fewer genes compared to A. lyrata, leading Nordborg to refer to it as “a bare-bones genome” during his talk.