The Organellar Genomes of Chromera and Vitrella, the Phototrophic Relatives of Apicomplexan Parasites

0450788 - BC 2016 RIV US eng J - Journal Article
Oborník, Miroslav - Lukeš, Julius
The Organellar Genomes of Chromera and Vitrella, the Phototrophic Relatives of Apicomplexan Parasites.
Annual Review of Microbiology. Roč. 69, October 2015 (2015), s. 129-144. ISSN 0066-4227. E-ISSN 1545-3251
R&D Projects: GA ČR GBP501/12/G055
EU Projects: European Commission(XE) 316304
Institutional support: RVO:60077344
Keywords : organellar genomes * mitochondrion * plastid * Apicomplexa * Alveolata * Chromera
Subject RIV: EE - Microbiology, Virology
Impact factor: 10.536, year: 2015

Apicomplexa are known to contain greatly reduced organellar genomes. Their mitochondria] genome carries only three protein-coding genes, and their plastid genome is reduced to a 35-kb-long circle. The discovery of coral-endosymbiotic algae Chromera velia and Vitrella brassicaformis, which share a common ancestry with Apicomplexa, provided an opportunity to study possibly ancestral forms of organellar genomes, a unique glimpse into the evolutionary history of apicomplexan parasites. The structurally similar mitochondrial genomes of Chromera and Vitrella differ in gene content, which is reflected in the composition of their respiratory chains. Thus, Chromera lacks respiratory complexes I and III, whereas Vitrella and apicomplexan parasites are missing only complex I. Plastid genomes differ substantially between these algae, particularly in structure: the Chromera plastid genome is a linear, 120-kb molecule with large and divergent genes, whereas the plastid genome of Vitrella is a highly compact circle that is only 85 kb long but nonetheless contains more genes than that of Chromera. It appears that organellar genomes have already been reduced in free-living phototrophic ancestors of apicomplexan parasites, and such reduction is not associated with parasitism.
Permanent Link: http://hdl.handle.net/11104/0252446