Please use this identifier to cite or link to this item:
Title: Tracing the evolution of the plastome and mitogenome in the Chloropicophyceae uncovered convergent tRNA gene losses and a variant plastid genetic code
Authors: Turmel, Monique
Lopes dos Santos, Adriana
Otis, Christian
Sergerie, Roxanne
Lemieux, Claude
Keywords: Prasinophyte Green Algae
DRNTU::Engineering::Environmental engineering
Picocystis Salinarum
Issue Date: 2019
Source: Turmel, M., Lopes dos Santos, A., Otis, C., Sergerie, R., & Lemieux, C. (2019). Tracing the evolution of the plastome and mitogenome in the Chloropicophyceae uncovered convergent tRNA gene losses and a variant plastid genetic code. Genome Biology and Evolution, 11(4), 1275-1292. doi: 10.1093/gbe/evz074
Series/Report no.: Genome Biology and Evolution
Abstract: The tiny green algae belonging to the Chloropicophyceae play a key role in marine phytoplankton communities; this newly erected class of prasinophytes comprises two genera (Chloropicon and Chloroparvula) containing each several species. We sequenced the plastomes and mitogenomes of eight Chloropicon and five Chloroparvula species to better delineate the phylogenetic affinities of these taxa and to infer the suite of changes that their organelle genomes sustained during evolution. The relationships resolved in organelle-based phylogenomic trees were essentially congruent with previously reported rRNA trees, and similar evolutionary trends but distinct dynamics were identified for the plastome and mitogenome. Although the plastome sustained considerable changes in gene content and order at the time the two genera split, subsequently it remained stable and maintained a very small size. The mitogenome, however, was remodeled more gradually and showed more fluctuation in size, mainly as a result of expansions/contractions of intergenic regions. Remarkably, the plastome and mitogenome lost a common set of three tRNA genes, with the trnI(cau) and trnL(uaa) losses being accompanied with important variations in codon usage. Unexpectedly, despite the disappearance of trnI(cau) from the plastome in the Chloroparvula lineage, AUA codons (the codons recognized by this gene product) were detected in certain plastid genes. By comparing the sequences of plastid protein-coding genes from chloropicophycean and phylogenetically diverse chlorophyte algae with those of the corresponding predicted proteins, we discovered that the AUA codon was reassigned from isoleucine to methionine in Chloroparvula. This noncanonical genetic code has not previously been uncovered in plastids.
DOI: 10.1093/gbe/evz074
Rights: © 2019 The Author(s). Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution. This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (, which permits non-commercial re-use, distribution, and reproduction in any medium, provided the original work is properly cited. For commercial re-use, please contact
Fulltext Permission: open
Fulltext Availability: With Fulltext
Appears in Collections:ASE Journal Articles

Citations 20

Updated on Jan 23, 2023

Web of ScienceTM
Citations 20

Updated on Jan 30, 2023

Page view(s)

Updated on Feb 5, 2023

Download(s) 50

Updated on Feb 5, 2023

Google ScholarTM




Items in DR-NTU are protected by copyright, with all rights reserved, unless otherwise indicated.