Metabolic pathway redundancy within the apicomplexan-dinoflagellate radiation argues against an ancient chromalveolate plastid
KAUST DepartmentPathogen Genomics Laboratory
Biological and Environmental Sciences and Engineering (BESE) Division
MetadataShow full item record
AbstractThe chromalveolate hypothesis presents an attractively simple explanation for the presence of red algal-derived secondary plastids in 5 major eukaryotic lineages: “chromista” phyla, cryptophytes, haptophytes and ochrophytes; and alveolate phyla, dinoflagellates and apicomplexans. It posits that a single secondary endosymbiotic event occurred in a common ancestor of these diverse groups, and that this ancient plastid has since been maintained by vertical inheritance only. Substantial testing of this hypothesis by molecular phylogenies has, however, consistently failed to provide support for the predicted monophyly of the host organisms that harbour these plastids—the “chromalveolates.” This lack of support does not disprove the chromalveolate hypothesis per se, but rather drives the proposed endosymbiosis deeper into the eukaryotic tree, and requires multiple plastid losses to have occurred within intervening aplastidic lineages. An alternative perspective on plastid evolution is offered by considering the metabolic partnership between the endosymbiont and its host cell. A recent analysis of metabolic pathways in a deep-branching dinoflagellate indicates a high level of pathway redundancy in the common ancestor of apicomplexans and dinoflagellates, and differential losses of these pathways soon after radiation of the major extant lineages. This suggests that vertical inheritance of an ancient plastid in alveolates is highly unlikely as it would necessitate maintenance of redundant pathways over very long evolutionary timescales.
CitationMetabolic pathway redundancy within the apicomplexan-dinoflagellate radiation argues against an ancient chromalveolate plastid 2015, 9 (1):e1116653 Communicative & Integrative Biology
SponsorsThis work was supported by the MRC (MR/M011690/1). SGG was supported by Science Foundation Ireland Grant 13/SIRG/ 2125.
PublisherInforma UK Limited
- Ancient recruitment by chromists of green algal genes encoding enzymes for carotenoid biosynthesis.
- Authors: Frommolt R, Werner S, Paulsen H, Goss R, Wilhelm C, Zauner S, Maier UG, Grossman AR, Bhattacharya D, Lohr M
- Issue date: 2008 Dec
- Chlorophyll c-containing plastid relationships based on analyses of a multigene data set with all four chromalveolate lineages.
- Authors: Bachvaroff TR, Sanchez Puerta MV, Delwiche CF
- Issue date: 2005 Sep
- Phylogenomic analysis supports the monophyly of cryptophytes and haptophytes and the association of rhizaria with chromalveolates.
- Authors: Hackett JD, Yoon HS, Li S, Reyes-Prieto A, Rümmele SE, Bhattacharya D
- Issue date: 2007 Aug
- PHYLOGENOMICS AND SECONDARY PLASTIDS: A LOOK BACK AND A LOOK AHEAD(1).
- Authors: Braun EL, Phillips N
- Issue date: 2008 Feb
- Chromera velia, endosymbioses and the rhodoplex hypothesis--plastid evolution in cryptophytes, alveolates, stramenopiles, and haptophytes (CASH lineages).
- Authors: Petersen J, Ludewig AK, Michael V, Bunk B, Jarek M, Baurain D, Brinkmann H
- Issue date: 2014 Mar