The cyanelles of the „living fossil“ Cyanophora paradoxa

We are interested in the biochemistry, molecular and cell biology of cyanelles. These peculiar plastids are found only in glaucocystophyte algae. Their unique peptidoglycan wall and the postulated carboxysome (both features are otherwise found in cyanobacteria only) render them a “missing link” of plastid evolution and an extant proof of the endosymbiotic theory. The data and results we generated working with Cyanophora paradoxa support the concept of a single primary endosymbiotic event leading to phototrophic eukaryotes: this vastly complicated process dating back approximately 1.2 billion years happened only once, i.e. between a certain type of heterotrophic eukaryotic host and a certain cyanobacterial species. Thus the kingdom Plantae can be considered as monophyletic.