Plant Genome I Conference
Town & Country Conference Center, San Diego, CA, November, 1992.
PG-I: 66pg1
THE PHYSICAL MAP OF ARABIDOPSIS THALIANA AND BEYOND.
Brian Hauge, Susan Hanley and Howard M. Goodman, Department of
molecular Biology, Massachusetts General Hospital, Boston, MA
02114.
Over the course of the past several years we have assembled
an overlapping cosmid map of the Arabidopsis thaliana genome, the
construction of which involved the characterization from primary
libraries of 20,000 clones by fingerprint analysis. Using
computer matching programs the clones have been aligned into some
750 overlapping groups or contigs that encompass approximately
91,000 kb representing between 90-95% of the Arabidopsis genome.
Having fingerprinted 10 genomic equivalents we have reached the
practical limit of random clone mapping. The majority of the gaps
in the map are expected to be small and can be attributed to the
fact that the linking cosmids are either non-existent or
under-represented in the cosmid libraries. To join the contigs
we are selecting the linking clones from the currently available
Arabidopsis YAC libraries. our linking strategy is to use YAC
clones to probe ordered cosmid grids which are representative of
the contigs and the unattached clones. Cosmids within a contig
are chosen such that there is minimal overlap between flanking
clones, yet the clones are representative of the entire contig.
The representative collection of 1920 cosmids can be arrayed on
two filters each the size of a microliter plate. To date we have
run 226 CHEF gels, purified 2,810 random YAC clones, and
completed approximately 2500 hybridizations. We are currently in
the very beginning stages of comparing the hybridization linkages
with the established contig map. For the physical map to be of
any utility it is necessary to align it with the classical
genetic linkage map. We have collaborated with Elliot Meyerowitz
and Piet Stam and Maarten Koornneef in integrating the two RFLP
maps and the physical and classical genetic maps of Arabidopsis.
Common markers have been incorporated into the maps facilitating
integration of the two data sets. The current map contains 123
classical morphological and 305 RFLP markers and a continuously
updated version is available in AATDB (an Arabidopsis thaliana
database).
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