Arsenophonus symbiosis with louse flies: multiple origins, coevolutionary dynamics, and metabolic significance

Martin Říhová, Jana, Gupta, Shruti, Darby, Alistair C ORCID: 0000-0002-3786-6209, Nováková, Eva and Hypša, Václav
(2023) Arsenophonus symbiosis with louse flies: multiple origins, coevolutionary dynamics, and metabolic significance. mSystems, 8 (5). e0070623-e0070623.

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Arsenophonus is a widespread insect symbiont with life strategies that vary from parasitism to obligate mutualism. In insects living exclusively on vertebrate blood, mutualistic Arsenophonus strains are presumed to provide B vitamins missing in the insect host diet. Hippoboscidae, obligate blood feeders related to tsetse flies, have been previously suggested to have acquired Arsenophonus symbionts in several independent events. Based on comparative genomic analyses of 11 Hippoboscidae-associated strains, 9 of them newly assembled, we reveal a wide range of their genomic characteristics and phylogenetic affiliations. Phylogenetic patterns and genomic traits split the strains into two different types. Seven strains display characteristics of obligate mutualists with significantly reduced genomes and long phylogenetic branches. The remaining four strains cluster on short branches, and their genomes resemble those of free-living bacteria or facultative symbionts. Both phylogenetic positions and genomic traits indicate that evolutionary history of the Hippoboscidae-Arsenophonus associations is a mixture of short-term coevolutions with at least four independent origins. The comparative approach to a reconstruction of B vitamin pathways across the available Arsenophonus genomes has produced two kinds of patterns. On one hand, it indicates the different importance of individual B vitamins in the host-symbiont interaction. While some (riboflavin, pantothenate, and folate) seem to be synthesized by all Hippoboscidae-associated obligate symbionts, pathways for others (thiamine, nicotinamide, and cobalamin) are mostly missing. On the other hand, the broad comparison has produced patterns that can serve as bases for further assessments of the pathways’ completeness and functionality.

Item Type: Article
Uncontrolled Keywords: Animals, Diptera, Anoplura, Bacteria, Enterobacteriaceae, Gammaproteobacteria, Vitamin B Complex, Phylogeny, Symbiosis, Insecta
Divisions: Faculty of Health and Life Sciences
Faculty of Health and Life Sciences > Institute of Infection, Veterinary and Ecological Sciences
Depositing User: Symplectic Admin
Date Deposited: 27 Nov 2023 12:31
Last Modified: 05 Jan 2024 13:26
DOI: 10.1128/msystems.00706-23
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