Sequence variations at a complex microsatellite locus in rice and its conservation in cereals

In an attempt to study changes associated with microsatellites in rice, the DNAs of cultivated rice, including indica and japonica varieties, and wild rice genotypes were amplified by the polymerase chain reaction with primer s flanking the (GATA)(n) and (AC)(n) repeats at a microsatellite-containing locus OS1E6 (Genebank accession number AFO16617) previously reported from a PstI rice (var. Malkolam) genomic library in pUC18. Eight alleles of vary ing sizes were obtained which were cloned and sequenced. Sequencing data in dicated that the size variations of the different alleles were due to diffe rences in the repeat number as well as to sequence variations in the region flanking the microsatellite motifs. In order to study the presence of this complex microsatellite-containing locus of rice in different cereals, thei r DNAs were amplified using primers flanking the OS1E6 locus. It was found that this locus was present in the various cereal genotypes analyzed, indic ating its conservation across different cereal members.