Abstract
Electrophoretic analysis reveals that the nucleus of the ultra-small eukaryotic alga Cyanidioschyzon merolae contains approximately 11.7×106 base pairs (11.7 Mb) of DNA. This compact genome is fragmented into 15 small chromosomes ranging in size from 410 to 1700 kb. The migratory behaviour of chloroplast DNA is consistent with the presence of a circular plastid genome of about 170 kb. The conformation of mitochondrial DNA resembles that in yeasts and fungi and is predominantly linear and heterogenous in size.