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 model system for plant molecular
genetics. The most important benefit of the physical map lies
in its support for map-based gene cloning experiments. Novel
genes identified, will not only provide insight into the
molecular mechanisms of plant function, but will also offer
the means to generate the future 3rd and 4th generation of
genetically engineered crops (this view is evidently
supported by the strong investments of the agro-biotech
industry into Arabidopsis research). From this point
of view, major achievements in Arabidopsis genome
research are of interest to the plant research community, the
general research community as well as the general public.
Prior to publication the results announced here were
continuously presented to the plant research community in the
Arabidopsis database of the Max Planck Institute of
Molecular Plant Physiology in Golm, Germany. The demand in
the public and private plant research communities for this
information is demonstrated by the fact that the web site
displaying the map data has already been accessed by several
hundred users from all over the world (http://www.mpimp-golm.mpg.de/101/mpi_mp_map/access.html). Thanks to the willingness of many colleagues
within the Arabidopsis research community by providing
individual information to be integrated into the map and the
attitude of all the co-authors to make all information
instantaneously available to the research community, an
extraordinary model of international collaboration has been
demonstrated:
Teresa Mozo1, Ken Dewar2, Pat Dunn3,
Joseph R. Ecker3, Sabine Fischer1,
Sebastian Kloska1, Hans Lehrach4, Marco
Marra5, Robert Martienssen6, Sebastian
Meier-Ewert7 & Thomas Altmann1.
1Max-Planck-Institut
für molekulare Pflanzenphysiologie,
Karl-Liebknecht-Str. 25, 14476 Golm, Germany. 2Whitehead
Institute/MIT Center of Genome Research, Cambridge, Massachusetts 02141, USA. 3Plant
Science Institute, Department of Biology, University of
Pennsylvania, Philadelphia, Pennsylvania 19104, USA. 4Max-Planck-Institut für molekulare Genetik, Ihnestr. 73, 14195 Berlin, Germany. 5Washington
University School of Medecine,
Genome Sequencing Center, St. Louis, Missouri 63108, USA. 6Cold
Spring Harbor, New York 11724, USA.
7GPC Aktiengesellschaft,
Lochhamer Str. 29, 82152 Martinsried, Germany.
Journal
Nature Genetics