AN INTEGRATED GENETIC RFLP MAP OF THE ARABIDOPSIS-THALIANA GENOME

We have assembled an integrated genetic/restriction fragment length polymorphism (RFLP) linkage map of the nuclear genome of the flowering plant Arabidopsis thaliana. The map is based on two independent sets of RFLP data, RFLP data for 123 new markers, and pairwise segregation data of 125 classical genetic markers. Mathematical integration of the independent data sets was performed using the JOINMAP computer package. Sixty-two markers common to two or more data sets were exploited to facilitate integration of the individual maps. The current map, which encompasses a total genetic distance of 520 cM, contains 125 classical genetic markers and 306 RFLP markers. Comparison of the integrated consensus map with the individual maps demonstrates that the overall linear order of the integrated map is in good agreement with the component maps. It must be emphasized, however, that the integrated map represents the 'best fit' which is clearly subject to the statistical limitations of the available data. We present several examples where local differences in map order are observed between the integrated and component maps. It is likely, given the problems associated with statistical integration of mapping data from different populations, that the integrated map will contain additional local inconsistencies and problematic regions. None the less, the unified map provides a framework for building an increasingly accurate and useful map. Subsequent refinements of the map will be available electronically and researchers are invited to submit revised map data to the corresponding author for inclusion in future updates (see Appendix 1).