DNA sequence organization in the flax genome.

The complexity of the flax genome has been determined by reassociation kinetics. The total complexity of one constituent genome was 3.5 . 10(8) nucleotide pairs. The single copy sequences comprised 44% of the genome and showed a long period interspersion pattern with the repetitive sequences. The repetitive sequences occurred in clusters which stretched for at least 10 000 base pairs. Within these clusters the individual repetitive elements were about 650 base pairs. These elements themselves showed little interspersion of different frequency classes in lengths less than 3000 base pairs. The repetitive sequence duplexes formed on reassociation, except for the satellite DNA, showed a high thermal stability. The fold-back DNA comprised 1% of the total genome, and was itself clustered in a small fraction of the genome.