THE GENETIC AND RFLP CHARACTERIZATION OF THE LEFT END OF LINKAGE GROUP-III IN CAENORHABDITIS-ELEGANS

A genetic approach was taken to identify new transposable element Tc1- dependent polymorphisms on the left end of linkage group III in the ne matode Caenorhabditis elegans. The cloning of the genomic DNA surround ing the Tc1 allowed the selection of overlapping clones (from the coll ection being used to assemble the physical map of the C elegans genome ). A contig of approximately 600-800 kbp in the region has been identi fied, the genetic map of the region has been refined, and 10 new RFLPs as well as at least four previously characterized genetic loci have b een positioned onto the physical map, to the resolution of a few cosmi ds. This analysis demonstrated the ability to combine physical and gen etic mapping for the rapid analysis of large genomic regions (0.5-1 Mb p) in genetically amenable eukaryotes.