The search for the missing link: A relic plastid in Perkinsus?

• Published in: International journal for parasitology Vol. 41; no. 12; pp. 1217 - 1229
• Main Authors: Fernández Robledo, José A., Caler, Elisabet, Matsuzaki, Motomichi, Keeling, Patrick J., Shanmugam, Dhanasekaran, Roos, David S., Vasta, Gerardo R.
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01.10.2011; Elsevier
• Subjects: Alveolata - genetics; Alveolata - pathogenicity; Alveolata - ultrastructure; Amino Acid Sequence; Animals; Apicomplexa; Apicoplast; Biological and medical sciences; Brackish; Chromalveolata hypothesis; Classical genetics, quantitative genetics, hybrids; Evolution, Molecular; Fundamental and applied biological sciences. Psychology; Genetics of eukaryotes. Biological and molecular evolution; Genome; Humans; Life cycle. Host-agent relationship. Pathogenesis; Marine; Microscopy, Electron; Models, Biological; Molecular Sequence Data; Ostreidae - parasitology; Perkinsozoa; Perkinsus; Perkinsus marinus; Plastid; Plastids - genetics; Plastids - ultrastructure; Protista; Protozoa; Protozoan; Sequence Alignment; Targeting; United States; United States; USA; Apicoplast; Targeting; Protozoan; Plastid; Genome; Chromalveolata hypothesis; Perkinsus; Protozoa; Parasite
• ISSN: 0020-7519; 1879-0135
• DOI: 10.1016/j.ijpara.2011.07.008

[Display omitted] ► Perkinsus marinus is a protozoan parasite that has devastated natural and farmed oyster populations in the USA. ► The Perkinsozoa is placed at the base of the dinoflagellate branch, close to its divergence from the Apicomplexa. ► Published information and recent genome data which support the presence of a plastid in Perkinsus are discussed. Perkinsus marinus (Phylum Perkinsozoa) is a protozoan parasite that has devastated natural and farmed oyster populations in the USA, significantly affecting the shellfish industry and the estuarine environment. The other two genera in the phylum, Parvilucifera and Rastrimonas, are parasites of microeukaryotes. The Perkinsozoa occupies a key position at the base of the dinoflagellate branch, close to its divergence from the Apicomplexa, a clade that includes parasitic protista, many harbouring a relic plastid. Thus, as a taxon that has also evolved toward parasitism, the Perkinsozoa has attracted the attention of biologists interested in the evolution of this organelle, both in its ultrastructure and the conservation, loss or transfer of its genes. A review of the recent literature reveals mounting evidence in support of the presence of a relic plastid in P. marinus, including the presence of multimembrane structures, characteristic metabolic pathways and proteins with a bipartite N-terminal extension. Further, these findings raise intriguing questions regarding the potential functions and unique adaptation of the putative plastid and/or plastid genes in the Perkinsozoa. In this review we analyse the above-mentioned evidence and evaluate the potential future directions and expected benefits of addressing such questions. Given the rapidly expanding molecular/genetic resources and methodological toolbox for Perkinsus spp., these organisms should complement the currently established models for investigating plastid evolution within the Chromalveolata.