CLONING AND CHARACTERIZATION OF A REPETITIVE SEQUENCE IN RYE (SECALE-CEREALE)

We describe here a repetitive DNA sequence common to both rye and whea t genomes. It was cloned as a 630 bp Xbal fragment (thus RXX630). RXX6 30 does not hybridize to barley DNA. It is highly repeated with ca. 10 (5) copies per rye genome and distributes unevenly on different rye ch romosomes. The complex patterns of rye genomic DNA in Southern hybridi zation indicated that it is not organized as blocks of simply tandem a rrays. Comparison of the nucleotide sequence of RXX630 with the databa se found no homology to any previously reported repetitive sequences i n rye and wheat.