RRC ID 58358
Author Janouskovec J, Horák A, Oborník M, Lukes J, Keeling PJ.
Title A common red algal origin of the apicomplexan, dinoflagellate, and heterokont plastids.
Journal Proc Natl Acad Sci U S A
Abstract The discovery of a nonphotosynthetic plastid in malaria and other apicomplexan parasites has sparked a contentious debate about its evolutionary origin. Molecular data have led to conflicting conclusions supporting either its green algal origin or red algal origin, perhaps in common with the plastid of related dinoflagellates. This distinction is critical to our understanding of apicomplexan evolution and the evolutionary history of endosymbiosis and photosynthesis; however, the two plastids are nearly impossible to compare due to their nonoverlapping information content. Here we describe the complete plastid genome sequences and plastid-associated data from two independent photosynthetic lineages represented by Chromera velia and an undescribed alga CCMP3155 that we show are closely related to apicomplexans. These plastids contain a suite of features retained in either apicomplexan (four plastid membranes, the ribosomal superoperon, conserved gene order) or dinoflagellate plastids (form II Rubisco acquired by horizontal transfer, transcript polyuridylylation, thylakoids stacked in triplets) and encode a full collective complement of their reduced gene sets. Together with whole plastid genome phylogenies, these characteristics provide multiple lines of evidence that the extant plastids of apicomplexans and dinoflagellates were inherited by linear descent from a common red algal endosymbiont. Our phylogenetic analyses also support their close relationship to plastids of heterokont algae, indicating they all derive from the same endosymbiosis. Altogether, these findings support a relatively simple path of linear descent for the evolution of photosynthesis in a large proportion of algae and emphasize plastid loss in several lineages (e.g., ciliates, Cryptosporidium, and Phytophthora).
Volume 107(24)
Pages 10949-54
Published 2010-6-15
DOI 10.1073/pnas.1003335107
PII 1003335107
PMID 20534454
PMC PMC2890776
MeSH Apicomplexa / classification Apicomplexa / genetics* Apicomplexa / ultrastructure Base Sequence Dinoflagellida / classification Dinoflagellida / genetics* Dinoflagellida / ultrastructure Evolution, Molecular* Gene Transfer, Horizontal Genome, Plastid Microscopy, Electron, Transmission Models, Genetic Molecular Sequence Data Photosynthesis / genetics Phylogeny Plastids / genetics* Plastids / ultrastructure Poly U / genetics RNA, Messenger / genetics Rhodophyta / classification Rhodophyta / genetics* Rhodophyta / ultrastructure Ribulose-Bisphosphate Carboxylase / genetics Symbiosis / genetics
IF 9.412
Times Cited 283
Algae NIES-4391