Figure 1.

Diagrams of cryptomonad and chlorarachniophyte cells and their nucleomorph (Nm) genomes. Cryptomonad and chlorarachniophyte cells (left) contain red and green algal endosymbionts, respectively, the reduced nuclei (nucleomorphs) of which encode three repeat-capped chromosomes (right). In cryptomonads, starch is stored within the endosymbiont and often sheaths the chloroplast's own pyrenoid (P), a specialized region of the chloroplast. In chlorarachniophytes, carbohydrate storage has moved from a chloroplast starch-based system to one based on β1,3 glucan within the host cell.