Protein trafficking pathways to plastids are directed by N-terminal targeting peptides. In plants this consists of a relatively simple transit peptide, while in organisms with secondary plastids (which reside within the endomembrane system) a signal peptide is appended to the transit peptide. Despite amino acid compositional differences between organisms, often due to nucleotide biases, the fea...

Chloroplasts are the sites of photosynthesis within the cell of land plants and algae. In non-photosynthetic tissues of plants, they are called plastids. Various lines of evidence, such as similarity of photosynthetic machineries and photosynthetic metabolic pathways as well as fossil records, suggested that the cyanobacteria are related to the origin of chloroplasts [1]. Now, cyanobacteria exh...

The Rhodophyta (red algae) are composed of the subclasses Bangiophycidae and Florideophycidae. Two evolutionarily interesting features of the Bangiophycidae are: (1) they are the ancestral pool from which the more morphologically complex taxa in the Florideophycidae have arisen and (2) they are the sources of the plastids, through secondary endosymbioses, for the Cryptophyta, Haptophyta, and th...

The three anomalously pigmented dinoflagellates Gymnodinium galatheanum, Gyrodinium aureolum, and Gymnodinium breve have plastids possessing 19'-hexanoyloxy-fucoxanthin as the major carotenoid rather than peridinin, which is characteristic of the majority of the dinoflagellates. Analyses of SSU rDNA from the plastid and the nuclear genome of these dinoflagellate species indicate that they have ...

To probe the earliest evolutionary events attending the origin of the five known genome types (archaebacterial, eubacterial, nuclear, mitochondrial and plastid), we have analyzed sequences corresponding to a ubiquitous, highly conserved core of secondary structure in small subunit rRNA. Our results support (i) the existence of three primary lineages (archaebacterial, eubacterial, and nuclear), ...

Mixotrophy, i.e., the capability of both phototrophy and phagotrophy within a single organism, is prominent trophic mode in aquatic ecosystems. Mixotrophic strategies can be highly advantageous when feeding or photosynthesis alone does not sustain metabolic needs. In current review, we discuss functional types mixotrophic marine protists (herein mixoplankton) context evolution. Permanent plasti...

Plastids and mitochondria each arose from a single endosymbiotic event and share many similarities in how they were reduced and integrated with their host. However, the subsequent evolution of the two organelles could hardly be more different: mitochondria are a stable fixture of eukaryotic cells that are neither lost nor shuffled between lineages, whereas plastid evolution has been a complex m...

Chlorarachniophytes are amoeboflagellate cercozoans that acquired a plastid by secondary endosymbiosis. Chlorarachniophytes are the last major group of algae for which there is no completely sequenced plastid genome. Here we describe the 69.2-kbp chloroplast genome of the model chlorarachniophyte Bigelowiella natans. The genome is highly reduced in size compared with plastids of other photosynt...

The establishment of a new plastid organelle by secondary endosymbiosis represents a series of events of massive complexity, and yet we know it has taken place multiple times because both green and red algae have been taken up by other eukaryotic lineages. Exactly how many times these events have succeeded, however, has been a matter of debate that significantly impacts how we view plastid evol...

Protozoan parasites of the phylum Apicomplexa contain three genetic elements: the nuclear and mitochondrial genomes characteristic of virtually all eukaryotic cells and a 35-kilobase circular extrachromosomal DNA. In situ hybridization techniques were used to localize the 35-kilobase DNA of Toxoplasma gondii to a discrete organelle surrounded by four membranes. Phylogenetic analysis of the tufA...