Plant & Animal Genomes XIV Conference

January 14-18, 2006
Town & Country Convention Center
San Diego, CA

Retrotransposons And Their Use As Molecular Markers In Brachypodium.

Ruslan Kalendar¹ , Alan H. Schulman^1,2

¹  MTT/BI Plant Genomics Laboratory, Institute of Biotechnology, University of Helsinki, Viikki Biocenter, P.O. Box 56, FIN-00014 Helsinki, Finland

²  Plant Breeding Biotechnology, MTT Agrifood Research Finland, Myllytie 10, FIN-31600 Jokioinen, Finland

Brachypodium distachyon, purple false brome, offers many advantages over the current model species, rice, for functional genomics relevant to the key temperate cereal crops and forage grasses. It is a diploid (2n=10) with a genome of only 150 Mbp, comparable to Arabidopsis thaliana and about 30% the size of that of rice, but is closely related evolutionarily to the Triticeae, which includes wheat, barley, and rye. It is easily transformed, has a rapid life cycle, does not shatter its seeds, and shows varying degrees of disease resistance in its wild populations. These features offer opportunities for rapid and effective map-based cloning and function verification of genes relevant to temperate agriculture, with potentially fewer of the difficulties stemming from lack of microsynteny between the Triticeae and rice. Retrotransposons comprise most of the intervening DNA between the genes in the large cereal genomes. The compact genome of B. distachyon is expected to contain comparatively few retrotransposons. Both as an aid to developing this plant as a model and to understand the structure and evolution of its genome, we are examining its genome for the presence, diversity, and distribution of the major classes of plant transposable elements, particularly the retrotransposons. These include the copia, gypsy, TRIM, and LARD groups of elements. These data are enabling us to develop retrotransposon-based molecular markers for the IRAP, REMAP, and SSAP methods, and later the RBIP method, for application as diversity and mapping tools.