IDENTIFICATION AND CHARACTERIZATION OF 14 TRANSPOSON-LIKE ELEMENTS INTHE NONCODING REGIONS OF MEMBERS OF THE XA21 FAMILY OF DISEASE RESISTANCE GENES IN RICE

The rice disease resistance gene Xa21, which encodes a receptor-like k inase, is a member of a multigene family. Based on comparisons of geno mic sequences of seven family members, seventeen transposon-like eleme nts were identified in the 5' and 3' flanking regions and introns of t hese genes. Sequence characterization revealed that these elements are diverse, showing similarity to maize Ds, CACTA and miniature inverted repeat-like elements, as well as novel elements. Only two elements we re located in presumed coding regions, indicating that integration of transposable elements at the Xa21 disease resistance locus occurred pr eferentially in noncoding regions.