Cryptomonads are natural experiments in genome miniaturization and cell simplification.
They are evolutionary chimaeras of a red alga and a non-photosynthetic host but unlike other chromophyte algae they retain the enslaved red algal nucleus as a minute 'nucleomorph'. The sequences of the three nucleomorph chromosomes of one of these elaborate 'Russian doll' cells reveals the most gene-dense eukaryotic genome known. This simplified chromosome could become a valuable model for the study of nuclear function. The sequence of the genome in one such nucleus is now revealed. Lilliputian A pared-down genome shows us how simple life can be.