In the latest issue of Nature Genetics
(volume 22; in July 1st 1999) the first ever-established
complete clone-based physical map of a plant genome is
published. The work was conducted in the group of Dr. Thomas
Altmann at the Max Planck Institute of Molecular Plant
Physiology, Golm, in collaboration with groups at the Max
Planck Institute of Molecular Genetics, Berlin, Germany, the
University of Pennsylvania, Philadelphia, and the Washington
University, St. Louis, USA. The map covers the entire nuclear
genome of the higher plant Arabidopsis thaliana.
Furthermore, this map is the first ever assembled (for any
organism) entirely on the basis of BAC (bacterial artificial
chromosome) clones, the premier system for cloning and
maintenance of large genomic DNA.
A physical map of a genome shows the localisation of all cloned DNA-segments of an organism in relative order and distribution over the different chromosomes. The existing Arabidopsis physical maps were predominantly based on YACs (yeast artificial chromosomes, a system for cloning and maintenance of large DNA fragments). The map presented here is highly reliable and offers strongly increased resolution, due to the properties of the BAC cloning system. It is a representation of the entire Arabidopsis genome as a set of 8,285 overlapping BAC clones. The sequence analysis of these BAC clones, currently being done in the framework of the International Arabidopsis Genome Initiative, will lead to elucidation of the complete genomic DNA sequence within the next years. To date, complete genomic DNA sequences are available only for yeast and several prokaryotic microorganisms. Arabidopsis thaliana - a small flowering plant which is also called Thales cress and which possesses a very small genome of only 5 chromosomes - is the major mod
Contact: Thomas Altmann