Title | Chimeric origins of ochrophytes and haptophytes revealed through an ancient plastid proteome |
Publication Type | Journal Article |
Year of Publication | 2017 |
Authors | Dorrell RG, Gile G, McCallum G, Méheust R, Bapteste EP, Klinger CM, Brillet-Guéguen L, Freeman KD, Richter DJ, Bowler C |
Journal | eLife |
Volume | 6 |
Pagination | 1–45 |
Date Published | may |
ISSN | 2050-084X |
Keywords | 2017, RCC1486, RCC1523, RCC1537, RCC1587, SBR$_\textrmP$hyto$_\textrmE$PPO |
Abstract | 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. |
URL | http://elifesciences.org/lookup/doi/10.7554/eLife.23717 |
DOI | 10.7554/eLife.23717 |