Photosynthetic organelles (plastids) come in many forms and were originally thought to have multiple origins. The complete genome of the thermophilic red alga Cyanidioschizon merolae provides further evidence that all plastids derive from a single endosymbiotic event more than 600 million years ago.

We analyzed nuclear-localized plastid-like DNA (nupDNA) fragments in protozoa, metazoa and fungi. Most eukaryotes that do not have plastids contain 40-5000 bp nupDNAs in their nuclear genomes. These nupDNA fragments are mainly derived from repeated regions of plastids and distribute through the whole genomes. A majority of nupDNA fragments is located on coding regions with very important functi...

The yellow variegated mutant of Arabidopsis thaliana is characterized by bright-yellow true leaves that turn green- and white-sectored as leaf development proceeds. Variegation is due to the action of a nuclear recessive gene. Whereas cells in the green sectors contain morphologically normal chloroplasts, cells in the yellow and white sectors are heteroplastidic and contain plastids with rudime...

The discovery of a nonphotosynthetic plastid in malaria and other apicomplexan parasites has sparked a contentious debate about its evolutionary origin. Molecular data have led to conflicting conclusions supporting either its green algal origin or red algal origin, perhaps in common with the plastid of related dinoflagellates. This distinction is critical to our understanding of apicomplexan ev...

Cellular response to osmotic stress is critical for survival and involves volume control through the regulated transport of osmolytes. Organelles may respond similarly to abrupt changes in cytoplasmic osmolarity. The plastids of the Arabidopsis thaliana leaf epidermis provide a model system for the study of organellar response to osmotic stress within the context of the cell. An Arabidopsis mut...

How easy is it to acquire an organelle? How easy is it to lose one? these questions underpin the current debate about the evolution of the plastid —that is, chloroplast—the organelle of photosynthesis in eukaryotic cells. the origin of the plastid has been traced to an endosymbiosis between a eukaryotic host cell and a cyanobacterial symbiont, the latter gradually ceding genetic control to the ...