Schematic representation of relationships between apicomplexan parasites and their closest relatives and the evolution of their plastids. The closest known branch to the 'true' apicomplexans (at top, including Coccidia, Piroplasms, Haemosporidians and the paraphyletic Gregarines) is a biologically undescribed lineage known only from plastid environmental surveys, the so-called ARL-V lineage. The nearest relatives that have been biologically characterized include a diverse array of predatory flagellates (Colpodella, Voromonas and Alphamonas), photosynthetic coral symbionts (Chromera and Vitrella) and a large number of unknown environmental lineages (many from coral, but also many from other environments). These are all in turn related to a large group including dinoflagellates and their closest relatives, the Perkinsids and Psammosa, both of which possess structures homologous to the apical complex, and the enigmatic predator Acavamons. The column to the right summarizes what we know about plastids in each lineage: red plastids indicate photosynthesis, colourless plastids indicates plastids that are known but non-photosynthetic. ARL-V is hypothesized to be photosynthetic but this has not been tested, and dinoflagellates contain about 50% photosynthetic and non-photosynthetic species. Lineages for which no plastid has been detected are indicated by a question mark. 

Schematic representation of relationships between apicomplexan parasites and their closest relatives and the evolution of their plastids. The closest known branch to the 'true' apicomplexans (at top, including Coccidia, Piroplasms, Haemosporidians and the paraphyletic Gregarines) is a biologically undescribed lineage known only from plastid environmental surveys, the so-called ARL-V lineage. The nearest relatives that have been biologically characterized include a diverse array of predatory flagellates (Colpodella, Voromonas and Alphamonas), photosynthetic coral symbionts (Chromera and Vitrella) and a large number of unknown environmental lineages (many from coral, but also many from other environments). These are all in turn related to a large group including dinoflagellates and their closest relatives, the Perkinsids and Psammosa, both of which possess structures homologous to the apical complex, and the enigmatic predator Acavamons. The column to the right summarizes what we know about plastids in each lineage: red plastids indicate photosynthesis, colourless plastids indicates plastids that are known but non-photosynthetic. ARL-V is hypothesized to be photosynthetic but this has not been tested, and dinoflagellates contain about 50% photosynthetic and non-photosynthetic species. Lineages for which no plastid has been detected are indicated by a question mark. 

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SUMMARY Malaria remains one of the most significant global public health burdens, with nearly half of the world's population at risk of infection. Malaria is not however a monolithic disease - it can be caused by multiple different parasite species of the Plasmodium genus, each of which can induce different symptoms and pathology, and which pose qu...

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... ancestor of the apicomplexans -in effect photosynthetic members of the apicomplexan lineage ( Moore et al. 2008). Chromera and Vitrella are two new genera of fully photosynthetic algae that were isolated from coral reefs, and branch near the base of the phylum Apicomplexa in molecular phylogenetic trees (Moore et al. 2008;Janouskovec et al. 2010) (Fig. 1). The plastid genomes of both have been fully sequenced, and demonstrated that apicomplexan plastids are derived from the same red algal endosymbiont that also gave rise to plastids of dinoflagellate and stramenopile algae ( Janouskovec et al. 2010). The Chromera and Vitrella plastid sequence data also revealed another unexpected ...
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... of other environments, many of which are far more thoroughly sampled, do not. Some of these are related to Chromera and Vitrella, most are new and independent lineages ( Janouskovec et al. 2012Janouskovec et al. , 2013. Indeed, the most common apicomplexan relative from coral is a new lineage known only as Apicomplexan Related Lineage-5 (ARL-V: Fig. 1). ARL-V is the closest known relative of apicomplex- ans, but its biology is totally unknown: it is as yet defined only by DNA sequences ( Janouskovec et al. 2012Janouskovec et al. , ...

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