The ultrastructure of the heterocyst and akinete of the blue-green algae (original) (raw)

The ultrastructure of the heterocyst and its development from the vegetative cell is described. The ultrastructure of the akinete is also described. The “mature” heterocyst (still attached to the filament) has an elaborate structure which is distinct from both that of the normal vegetative cell and the akinete (the normal reproductive cell).

Despite the extra structural detail seen in the electron micrographs, the observations do not indicate a likely physiological role for the heterocyst. However, since the developing-mature heterocyst has an organised structure, it is probable that it has an active metabolism. In contrast, the detached heterocyst has a highly disorganised structure and, for this reason, it is likely to be metabolically inactive and incapable of germination.