Host phylogeny and ecology, but not host physiology, are the main drivers of (dis)similarity between the host spectra of fleas: application of a novel ordination approach to regional assemblages from four continents

Comparative ecology uses interspecific relationships among traits, while accounting for the phylogenetic non-independence of species, to uncover general evolutionary processes. Applied to biogeographic questions, it can be a powerful tool to explain the spatial distribution of organisms. Here, we review how comparative methods can elucidate biogeographic patterns and processes, using analyses of distributional data on parasites (fleas and helminths) as case studies. Methods exist to detect phylogenetic signals, i.e. the degree of phylogenetic dependence of a given character, and either to control for these signals in statistical analyses of interspecific data, or to measure their contribution to variance. Parasite–host interactions present a special case, as a given trait may be a parasite trait, a host trait or a property of the coevolved association rather than of one participant only. For some analyses, it is therefore necessary to correct simultaneously for both parasite phylogeny and host phylogeny, or to evaluate which has the greatest influence on trait expression. Using comparative approaches, we show that two fundamental properties of parasites, their niche breadth, i.e. host specificity, and the nature of their life cycle, can explain interspecific and latitudinal variation in the sizes of their geographical ranges, or rates of distance decay in the similarity of parasite communities. These findings illustrate the ways in which phylogenetically based comparative methods can contribute to biogeographic research.

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Commentary: Phyllostomid bat microbiome composition is associated to host phylogeny and feeding strategies

Frontiers in Microbiology ◽

10.3389/fmicb.2018.02863 ◽

2018 ◽

Vol 9 ◽

Author(s):

Arinjay Banerjee ◽

Edel Pérez-López ◽

Karen Mossman

Keyword(s):

Feeding Strategies ◽

Microbiome Composition ◽

Host Phylogeny

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Biogeography and Independent Diversification in the Protist Symbiont Community of Heterotermes tenuis

Frontiers in Ecology and Evolution ◽

10.3389/fevo.2021.640625 ◽

2021 ◽

Vol 9 ◽

Author(s):

Francesca De Martini ◽

Nicole L. Coots ◽

Daniel E. Jasso-Selles ◽

Jordyn Shevat ◽

Alison Ravenscraft ◽

...

Keyword(s):

Regional Differences ◽

Amplicon Sequencing ◽

Genetic Distances ◽

Species Level ◽

Mantel Tests ◽

Geographical Distances ◽

Host Phylogeny ◽

Single Cell Isolation ◽

Host Genetic ◽

Protist Species

The eukaryotic microbiome of “lower” termites is highly stable and host-specific. This is due to the mutually obligate nature of the symbiosis and the direct inheritance of protists by proctodeal trophallaxis. However, vertical transmission is occasionally imperfect, resulting in daughter colonies that lack one or more of the expected protist species. This phenomenon could conceivably lead to regional differences in protist community composition within a host species. Here, we have characterized the protist symbiont community of Heterotermes tenuis (Hagen) (Blattodea: Rhinotermitidae) from samples spanning South and Central America. Using light microscopy, single cell isolation, and amplicon sequencing, we report eight species-level protist phylotypes belonging to four genera in the phylum Parabasalia. The diversity and distribution of each phylotype’s 18S rRNA amplicon sequence variants (ASVs) mostly did not correlate with geographical or host genetic distances according to Mantel tests, consistent with the lack of correlation we observed between host genetic and geographical distances. However, the ASV distances of Holomastigotoides Ht3 were significantly correlated with geography while those of Holomastigotoides Ht1 were significantly correlated with host phylogeny. These results suggest mechanisms by which termite-associated protist species may diversify independently of each other and of their hosts, shedding light on the coevolutionary dynamics of this important symbiosis.

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Host phylogeny drives the structure and diversity of insect microbiota

10.1101/2021.07.19.452888 ◽

2021 ◽

Author(s):

Antonino Malacrino'

Keyword(s):

Bacterial Communities ◽

Management Practices ◽

Life Stage ◽

Future Research ◽

Sequencing Data ◽

Insect Nutrition ◽

Common Framework ◽

Host Phylogeny ◽

Insect Taxonomy ◽

Outstanding Question

Microorganisms have an enormous impact on most of the life that inhabits our planet. Insects are an excellent example, as research showed that several microbial species are essential for insect nutrition, reproduction, fitness, defence and many other functions. More recently, we assisted to an exponential growth of studies describing the taxonomical composition of bacterial communities across insects' phylogeny. However, there is still an outstanding question that needs to be answered: which factors contribute most in shaping insects' microbiomes? This study tries to find an answer to this question by taking advantage of publicly available sequencing data and reanalysing over 4,000 samples of insect-associated bacterial communities under a common framework. Results suggest that insect taxonomy has a wider impact on the structure and diversity of their associated microbial communities than the other factors considered (diet, sex, life stage, sample origin and treatment). Also, a survey of the literature highlights several methodological limitations that needs to be considered in future research endeavours. This study proofs the amount of collective effort that lead to the current understanding of insect-microbiota interactions and their influence on insect biology, ecology and evolution with potential impact on insect conservation and management practices.

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Beyond Slam: the DUF560 family outer membrane protein superfamily SPAM has distinct network subclusters that suggest a role in non-lipidated substrate transport and bacterial environmental adaptation

10.1101/2020.01.20.912956 ◽

2020 ◽

Author(s):

Terra J. Mauer ◽

Alex S. Grossman ◽

Katrina T. Forest ◽

Heidi Goodrich-Blair

Keyword(s):

Host Range ◽

Outer Membrane ◽

Binding Protein ◽

Sequence Similarity ◽

Outer Membrane Proteins ◽

Environmental Adaptation ◽

Host Cells ◽

Xenorhabdus Nematophila ◽

Associated Bacteria ◽

Host Phylogeny

AbstractIn host-associated bacteria, surface and secreted proteins mediate acquisition of nutrients, interactions with host cells, and specificity of host-range and tissue-localization. In Gram-negative bacteria, the mechanism by which many proteins cross, become embedded within, or become tethered to the outer membrane remains unclear. The domain of unknown function (DUF)560 occurs in outer membrane proteins found throughout and beyond the proteobacteria. Functionally characterized DUF560 representatives include NilB, a host-range specificity determinant of the nematode-mutualist Xenorhabdus nematophila and the surface lipoprotein assembly modulators (Slam), Slam1 and Slam2 which facilitate surface exposure of lipoproteins in the human pathogen Neisseria meningitidis. Through network analysis of protein sequence similarity we show that DUF560 subclusters exist and correspond with organism lifestyle rather than with taxonomy, suggesting a role for these proteins in environmental adaptation. Cluster 1 had the greatest number of representative proteins, was dominated by homologs from animal-associated symbionts, and was composed of subclusters: 1A (containing NilB, Slam1, and Slam2), 1B, and 1C. Genome neighborhood networks revealed that Cluster 1A DUF560 members are strongly associated with TonB, TonB-dependent receptors, and predicted co-receptors such as the Slam1 lipoprotein substrates transferrin binding protein and lactoferrin binding protein. The genome neighborhood network of Cluster 1B sequences are similarly dominated by TonB loci, but typically the associated co-receptors (the presumed DUF560 substrates) are predicted to be non-lipidated. We suggest that these subclusters within the DUF560 protein family indicate distinctive activities and that Slam activity may be characteristic of Cluster 1A members but not all DUF560 homologs. For Cluster 1 DUF560 homologs we propose the name SPAM (Surface/Secreted Protein Associated Outer Membrane Proteins) to accommodate the potential for non-lipoprotein substrates or different activities. We show that the repertoire of SPAM proteins in Xenorhabdus correlates with host phylogeny, suggesting that the host environment drives the evolution of these symbiont-encoded proteins. This pattern of selection for specific sequences based on host physiology and/or environmental factors may extend to other clusters of the DUF560 family.

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