TY - JOUR
T1 - Chimeric origins of ochrophytes and haptophytes revealed through an ancient plastid proteome
AU - Dorrell, Richard G.
AU - Gile, Gillian
AU - McCallum, Giselle
AU - Méheust, Raphaël
AU - Bapteste, Eric P.
AU - Klinger, Christen M.
AU - Brillet-Guéguen, Loraine
AU - Freeman, Katalina D.
AU - Richter, Daniel J.
AU - Bowler, Chris
N1 - Publisher Copyright:
© Dorrell et al.
PY - 2017/5/12
Y1 - 2017/5/12
N2 - Plastids are supported by a wide range of proteins encoded within the nucleus and imported from the cytoplasm. These plastid-targeted proteins may originate from the endosymbiont, the host, or other sources entirely. Here, we identify and characterise 770 plastid- targeted proteins that are conserved across the ochrophytes, a major group of algae including diatoms, pelagophytes and kelps, that possess plastids derived from red algae. We show that the ancestral ochrophyte plastid proteome was an evolutionary chimera, with 25% of its phylogenetically tractable nucleus-encoded proteins deriving from green algae. We additionally show that functional mixing of host and plastid proteomes, such as through dual-targeting, is an ancestral feature of plastid evolution. Finally, we detect a clear phylogenetic signal from one ochrophyte subgroup, the lineage containing pelagophytes and dictyochophytes, in plastid- targeted proteins from another major algal lineage, the haptophytes. This may represent a possible serial endosymbiosis event deep in eukaryotic evolutionary history.
AB - Plastids are supported by a wide range of proteins encoded within the nucleus and imported from the cytoplasm. These plastid-targeted proteins may originate from the endosymbiont, the host, or other sources entirely. Here, we identify and characterise 770 plastid- targeted proteins that are conserved across the ochrophytes, a major group of algae including diatoms, pelagophytes and kelps, that possess plastids derived from red algae. We show that the ancestral ochrophyte plastid proteome was an evolutionary chimera, with 25% of its phylogenetically tractable nucleus-encoded proteins deriving from green algae. We additionally show that functional mixing of host and plastid proteomes, such as through dual-targeting, is an ancestral feature of plastid evolution. Finally, we detect a clear phylogenetic signal from one ochrophyte subgroup, the lineage containing pelagophytes and dictyochophytes, in plastid- targeted proteins from another major algal lineage, the haptophytes. This may represent a possible serial endosymbiosis event deep in eukaryotic evolutionary history.
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U2 - 10.7554/eLife.23717
DO - 10.7554/eLife.23717
M3 - Article
C2 - 28498102
AN - SCOPUS:85020829663
SN - 2050-084X
VL - 6
JO - eLife
JF - eLife
M1 - e23717
ER -