Nucleotide sequence organisation in the rye genome.

Nucleotide sequence organisation in the genome of rye, Secale cereale, has been studied using renaturation kinetics and S1 nuclease digestion of the renatured products. Approximately 25 to 30% of the genome consists of very slowly renaturing, possibly single copy sequences. Most, if not all, of these sequences are interspersed between repeated sequences and are between 400 and 3500 nucleotide pairs long. Approximately 70 to 75% of the genome consists of repeated sequences. The more highly diverged repeated sequences (30% of the genome) which fail to renature under highly stringent renaturation conditions range from 500 to more than 5000 base pairs long and are interspersed in the chromosomes with less diverged repeated sequences (40% of the genome) which are usually less than 800 nucleotide pairs long. Four percent of the genome consists of very rapidly reannealing sequences which may be inverted duplications. These sequences may be in clusters distributed through at least 30% of the genome.