IDENTIFICATION AND CHARACTERIZATION OF PUTATIVE TRANSPOSABLE DNA ELEMENTS IN SOLANACEOUS PLANTS AND CAENORHABDITIS-ELEGANS

Several families of putative transposable elements (TrEs) in both sola naceous plants and Caenorhabditis elegans have been identified by scre ening the DNA data base for inverted repeated domains present in multi ple copies in the genome, The elements are localized within intron and flanking regions of many genes, These elements consist of two inverte d repeats flanking sequences ranging from 5 bp to >500 bp, Identificat ion of multiple elements in which sequence conservation includes both the flanking and internal regions implies that these TrEs are capable of duplicative transposition, Two of the elements were identified in p romoter regions of the tomato (Lycopersicon esculentum) polygalacturon ase and potato (Solanum tuberosum) Win1 genes, The element in the poly galacturonase promoter spans a known regulatory region. In both cases, ancestral DNA sequences, which represent potential recombination targ et sequences prior to insertion of the elements, have been cloned from related species, The sequences of the inverted repeated domains in pl ants and C, elegans show a high degree of phylogenetic conservation, W hile frequency of the different elements is variable, some are present in very high copy number, A member of a single C, elegans TrE family is observed approximately once every 20 kb in the genome, The abundanc e of the described TrEs suggests utility in the genomic analysis of th ese and related organisms.