Each chromosome is represented as a coloured bar. Sequenced portions are red, telomeric and centromeric regions are light blue, heterochromatic knobs are shown black and the rDNA repeat regions are magenta. The unsequenced telomeres 2N and 4N are depicted with dashed lines. Telomeres are not drawn to scale. Images of DAPI-stained chromosomes were kindly supplied by P. Fransz. The frequency of features was given pseudo-colour assignments, from red (high density) to deep blue (low density). Gene density (‘Genes’) ranged from 38 per 100 kb to 1 gene per 100 kb; expressed sequence tag matches (‘ESTs’) ranged from more than 200 per 100 kb to 1 per 100 kb. Transposable element densities (‘TEs’) ranged from 33 per 100 kb to 1 per 100 kb. Mitochondrial and chloroplast insertions (‘MT/CP’) were assigned black and green tick marks, respectively. Transfer RNAs and small nucleolar RNAs (‘RNAs’) were assigned black and red ticks marks, respectively.