AN INTEGRATED GENETIC RFLP MAP OF THE ARABIDOPSIS-THALIANA GENOME

We have assembled an integrated genetic/restriction fragment length po lymorphism (RFLP) linkage map of the nuclear genome of the flowering p lant Arabidopsis thaliana. The map is based on two independent sets of RFLP data, RFLP data for 123 new markers, and pairwise segregation da ta of 125 classical genetic markers. Mathematical integration of the i ndependent data sets was performed using the JOINMAP computer package. Sixty-two markers common to two or more data sets were exploited to f acilitate integration of the individual maps. The current map, which e ncompasses a total genetic distance of 520 cM, contains 125 classical genetic markers and 306 RFLP markers. Comparison of the integrated con sensus map with the individual maps demonstrates that the overall line ar order of the integrated map is in good agreement with the component maps. It must be emphasized, however, that the integrated map represe nts the 'best fit' which is clearly subject to the statistical limitat ions of the available data. We present several examples where local di fferences in map order are observed between the integrated and compone nt maps. It is likely, given the problems associated with statistical integration of mapping data from different populations, that the integ rated map will contain additional local inconsistencies and problemati c regions. None the less, the unified map provides a framework for bui lding an increasingly accurate and useful map. Subsequent refinements of the map will be available electronically and researchers are invite d to submit revised map data to the corresponding author for inclusion in future updates (see Appendix 1).