'<i>Candidatus</i> Megaira' are diverse symbionts of algae and ciliates with the potential for defensive symbiosis.



Davison, Helen Rebecca ORCID: 0000-0002-4302-5756, Hurst, Gregory DD ORCID: 0000-0002-7163-7784 and Siozios, Stefanos ORCID: 0000-0002-1104-7061
(2023) '<i>Candidatus</i> Megaira' are diverse symbionts of algae and ciliates with the potential for defensive symbiosis. Microbial genomics, 9 (3). mgen000950-.

Access the full-text of this item by clicking on the Open Access link.

Abstract

Symbiotic microbes from the genus 'Candidatus Megaira' ( Rickettsiales ) are known to be common associates of algae and ciliates. However, genomic resources for these bacteria are scarce, limiting our understanding of their diversity and biology. We therefore utilize Sequence Read Archive and metagenomic assemblies to explore the diversity of this genus. We successfully extract four draft 'Ca. Megaira' genomes including one complete scaffold for a 'Ca. Megaira' and identify an additional 14 draft genomes from uncategorized environmental metagenome-assembled genomes. We use this information to resolve the phylogeny for the hyper-diverse 'Ca. Megaira', with hosts broadly spanning ciliates, and micro- and macro-algae, and find that the current single genus designation 'Ca. Megaira' significantly underestimates their diversity. We also evaluate the metabolic potential and diversity of ''Ca. Megaira' from this new genomic data and find no clear evidence of nutritional symbiosis. In contrast, we hypothesize a potential for defensive symbiosis in 'Ca. Megaira'. Intriguingly, one symbiont genome revealed a proliferation of ORFs with ankyrin, tetratricopeptide and leucine-rich repeats such as those observed in the genus Wolbachia where they are considered important for host–symbiont protein–protein interactions. Onward research should investigate the phenotypic interactions between 'Ca. Megaira' and their various potential hosts, including the economically important Nemacystus decipiens, and target acquisition of genomic information to reflect the diversity of this massively variable group.

Item Type: Article
Uncontrolled Keywords: symbiosis, bacteria, Rickettsiales, algae, ciliates, microeukaryotes
Divisions: Faculty of Health and Life Sciences
Faculty of Health and Life Sciences > Institute of Infection, Veterinary and Ecological Sciences
Faculty of Health and Life Sciences > Institute of Systems, Molecular and Integrative Biology
Depositing User: Symplectic Admin
Date Deposited: 21 Mar 2023 08:24
Last Modified: 15 Mar 2024 02:05
DOI: 10.1099/mgen.0.000950
Open Access URL: https://doi.org/10.1099/mgen.0.000950
Related URLs:
URI: https://livrepository.liverpool.ac.uk/id/eprint/3169176