Mitochondrial genome sequence of the protist Ancyromonas sigmoides Kent, 1881 (Ancyromonadida) from the Sugluk Inlet, Hudson Strait, Nunavik, Québec

Romain Gastineau; Sara Harðardóttir; Caroline Guilmette; Claude Lemieux; Monique Turmel; Christian Otis; Brian Boyle; Roger C Levesque; Jeff Gauthier; Marianne Potvin; Connie Lovejoy

doi:10.3389/fmicb.2023.1275665

Mitochondrial genome sequence of the protist Ancyromonas sigmoides Kent, 1881 (Ancyromonadida) from the Sugluk Inlet, Hudson Strait, Nunavik, Québec

Front Microbiol. 2023 Dec 8:14:1275665. doi: 10.3389/fmicb.2023.1275665. eCollection 2023.

Authors

Romain Gastineau¹, Sara Harðardóttir^{2

3

4}, Caroline Guilmette³, Claude Lemieux^{5

6}, Monique Turmel^{5

6}, Christian Otis^{5

7}, Brian Boyle^{5

7}, Roger C Levesque⁵, Jeff Gauthier⁵, Marianne Potvin^{5

6}, Connie Lovejoy^{3

5}

Affiliations

¹ Institute of Marine and Environmental Sciences, University of Szczecin, Szczecin, Poland.
² Geological Survey of Denmark and Greenland, København K, Denmark.
³ Biology Department, Takuvik International Research Laboratory (IRL 3376), Université Laval - CNRS, Québec City, QC, Canada.
⁴ The Marine and Freshwater Research Institute in Iceland, Hafnarfjörður, Iceland.
⁵ Institut de Biologie Intégrative et des Systèmes, Université Laval, Québec City, QC, Canada.
⁶ Département de biochimie, de microbiologie et de bio-Informatique, Université Laval, Québec City, QC, Canada.
⁷ Plateforme d'Analyse génomique, Institut de Biologie Intégrative et des Systèmes, Université Laval, Québec City, QC, Canada.

Abstract

Introduction: There is little information on evolutionarily ancient eukaryotes, which are often referred to as basal eukaryotes, in Arctic waters. Despite earlier studies being conducted in the Russian White Sea, only few have been reported.

Methods: Following a shotgun sequence survey of diatom cultures from Sugluk Inlet off the Hudson Strait in Northern Québec, we obtained the complete mitochondrial genome and the operon of nuclear ribosomal RNA genes from a strain that matches that of Ancyromonas sigmoides (Kent, 1881).

Results: The sequence of the mitogenome retrieved was 41,889 bp in length and encoded 38 protein-coding genes, 5 non-conserved open-reading frames, and 2 rRNA and 24 tRNA genes. The mitogenome has retained sdh2 and sdh3, two genes of the succinate dehydrogenase complex, which are sometimes found among basal eukaryotes but seemingly missing among the Malawimonadidae, a lineage sister to Ancyromonadida in some phylogenies. The phylogeny inferred from the 18S rRNA gene associated A. sigmoides from Sugluk Inlet with several other strains originating from the Arctic. The study also unveiled the presence of a metagenomic sequence ascribed to bacteria in GenBank, but it was clearly a mitochondrial genome with a gene content highly similar to that of A. sigmoides, including the non-conserved open-reading frames.

Discussion: After re-annotation, a phylogeny was inferred from mitochondrial protein sequences, and it strongly associated A. sigmoides with the misidentified organism, with the two being possibly conspecific or sibling species as they are more similar to one another than to species of the genus Malawimonas. Overall our phylogeny showed that the ice associated ancryomonads were clearly distinct from more southerly strains.

Keywords: Ancyromonas sigmoides; Arctic; Nunavik; basal protist; mitogenome; phylogeny.

Grants and funding

The author(s) declare financial support was received for the research, authorship, and/or publication of this article. This study received funding from the European Union’s Horizon 2020 research and innovation program under the Marie Skłodowska-Curie grant agreement no: 846860 (grant to SH and CLo). CLe and MT were supported by the grant RGPIN-2017-04506 from the Natural Sciences and Engineering Research Council of Canada (NSERC). BB and CO were supported by the “Programme d’appui aux plateformes technologiques stratégiques” from the Ministère de l’Économie, de l’Innovation et de l’Énergie Québec. CLo received additional funds from NSERC Discovery and Northern Supplement, with support from the ArcticNet, a Network of Centers of Excellence of Canada, Canada First Research Excellence Fund to Sentinelle Nord and Fonds de Recherche du Québec Nature et Technologies (FRQNT) to Québec Océan. Comput Canada access is also acknowledged.