Biology subjects

Dubilier, N.

Publications and source records attributed to Dubilier, N..

At least 19 recordsLinked to original sources

bioRxiv2026

Spatial lipidomics suggests fatty acid scavenging by an intranuclear parasite

Bacteria of the family Endozoicomonadaceae are widely associated with marine animals, yet their in situ metabolism remains mostly unknown. Genomic studies suggest that members of this family engage in extensive metabolic exchange with their hosts, ranging from nutrient provision in mutualistic sponge and coral symbioses to strong dependence on host metabolites like lipids in parasitic associations. Here, we study the lipid phenotype of the parasitic bacterium Candidatus Endonucleibacter childressi in its native tissue environment. The bacterium infects epithelial cells in the gill of the deep-sea mussel Gigantidas childressi and co-occurs with the mussel chemosynthetic symbionts providing a system to compare lipid profiles of symbiotic and parasitic gammaproteobacteria. We linked bacterial identity to metabolic phenotypes by combining mass spectrometry imaging with 16S rRNA fluorescence in situ hybridization. We identified phospholipids characteristic of regions infected with Ca. Endonucleibacter childressi. A subset of these lipids was also detected in symbiont-colonized regions, revealing a partial overlap in the phospholipid profiles of the two gammaproteobacteria. Fatty acids from PEs assigned to Ca. Endonucleibacter childressi contained polyunsaturated fatty acids such as FA 16:3, FA 18:3 or FA 18:4 which have not been reported from cultured close relatives. We hypothesize that the observed fatty acid profile may reflect adaptations to a host-associated lifestyle which involves the acquisition and remodeling of host-derived fatty acids. Our findings demonstrate the value of characterizing bacterial metabolic phenotypes directly in their native tissue environment and highlight the potential of spatial lipidomics to reveal metabolic dependencies in host-microbe associations.

microbiology↗

bioRxiv2025

Chemosynthetic Symbioses as Hidden Hubs of DMSP and Organosulfur Cycling in Marine Sediments

Chemosynthetic symbioses between animals and bacteria are known to underpin productivity in the deep sea, yet the diversity of energy and carbon sources sustaining these associations in shallow-water environments remains poorly understood. Dimethylsulfoniopropionate (DMSP) is highly abundant in coastal habitats, where it is produced by seagrasses, phytoplankton, and heterotrophic bacteria, and occurs together with its breakdown product dimethyl sulfide (DMS) in shallow-water sediments. Here we show, supported by genomic and transcriptomic evidence, that DMSP and DMS cycling are integral to the energy and carbon metabolism of the gutless oligochaete Olavius algarvensis and its chemosynthetic symbionts. By assigning DMSP degradation pathways to individual members of the hosts microbial community, we reconstructed a network integrating demethylation and cleavage with energy conservation, methionine biosynthesis, and acetate assimilation into polyhydroxyalkanoates. We also identified a host-encoded methanethiol oxidase (MtoX) suggesting host participation in MeSH detoxification. Comparative metagenomic analyses of more than 60 gutless oligochaete species from globally distributed habitats showed that key DMSP- and DMS-processing genes (dddP, dmdA, tmm, dmsA) are widespread, indicating that organosulfur metabolism is a conserved feature of these symbioses. Our findings expand the recognized metabolic repertoire of shallow-water chemosynthetic symbioses and provide evidence that these associations directly contribute to marine DMSP and DMS cycling.

microbiology↗

bioRxiv2025

Evolutionary history of the widespread association between placozoans and diverse Rickettsiales symbionts

Rickettsiales are an enigmatic clade of strictly host-associated bacteria with some very common phylotypes in aquatic habitats. Despite amplicon- and metagenomic sequencing-based observations, the roles of these aquatic Rickettsiales are still unknown, as their genomes feature both beneficial and parasitic traits. In placozoans, microscopy-based observations of intracellular and Rickettsia-like-organisms point to Rickettsiales as common and abundant symbionts. We therefore systematically studied the microbiomes of placozoans to understand the eco-evolutionary dynamics of their associated Rickettsiales. Single-animal metagenomics revealed a widespread association of placozoans with Rickettsiales from three clades of Ca. Midichloriaceae, which were present in all but two placozoan lineages. A comparative phylogenetic analysis of placozoans and their Rickettsiales symbionts revealed host species-specific switches among Rickettsiales clades in several placozoan lineages. Our combination of evolutionary analyses, genome annotations, and expression data indicate different functional roles of these Rickettsiales clades, with some clearly diverging from a classical parasitic lifestyle by the loss of all ATP scavenging machinery. One of placozoan lineages that lacked Ca. Midichloriaceae was instead associated with Rickettsiaceae symbionts, while another was completely devoid of Rickettsiales symbionts. Our imaging data of fibre cells entirely free of Rickettsiales underscores previously unrecognized variation in placozoan-microbe associations. Early-branching invertebrates, including placozoans as well as many corals, are gaining increasing traction as emerging models across the life sciences. Our data and analyses show that it is important to consider the specific endosymbiont groups and their ecology in a given host, as these symbionts likely influence the hosts cellular and organismal biology.

microbiology↗

bioRxiv2024

Genomic and proteomic characterization of sulfate-reducing symbionts of gutless marine annelids

Sulfate-reducing bacteria (SRB) are widespread in marine and terrestrial environments, where they often form syntrophic associations with bacteria, archaea, and eukaryotes. Among the most intimate of these are multipartite symbioses in gutless marine oligochaete worms, which host SRB and sulfur-oxidizing endosymbionts that engage in a syntrophic exchange of sulfur compounds. Despite decades of research on free-living SRB, the metabolic traits that enable SRB to persist in symbiosis, and how these differ across hosts and environments, remain poorly understood. Here, we show that a globally distributed clade of symbiotic SRB has a conserved core metabolism that diverges markedly from free-living relatives. Using comparative genomics and metaproteomics, we reveal that these endosymbionts retain key traits of SRB such as sulfate reduction, complete oxidation of acetate to CO2, amino acid degradation for nitrogen acquisition, and transport of essential nutrients. However, they exhibit a more oxygen-tolerant metabolism and lack typical nutrient-scavenging mechanisms of free-living SRB. One symbiont-specific trait, the glyoxylate bypass, was consistently expressed in situ and may serve both in reactive oxygen species defence and in biomass generation. The enrichment and expression of oxygen-tolerant pathways, coupled with the loss of nutrient-scavenging functions, indicate specialization to a host-associated, redox-fluctuating environment distinct from that of free-living SRB. Consistent with this shift, symbiont genomes are larger than those of free-living relatives, contrasting with genome reduction in many endosymbionts and reinforcing the importance of metabolic versatility. Our findings provide a framework for understanding how metabolic flexibility enables SRB to persist in long-term multipartite symbioses across diverse marine ecosystems.

microbiology↗

bioRxiv2023

Mechanism of high energy efficiency of carbon fixation by sulfur-oxidizing symbionts revealed by single-cell analyses and metabolic modeling

In chemosynthetic symbioses between marine invertebrates and autotrophic sulfur-oxidizing bacteria the symbionts feed their host by producing organic compounds from CO2 using reduced sulfur compounds as an energy source. One such symbiosis, the gutless marine worm Olavius algarvensis harbors at least five bacterial symbionts of which four have the genetic potential for an autotrophic metabolism. In this study we combined single-cell analyses of CO2 fixation, CO2 release and bulk uptake, with measurements of O2 respiration, sulfur content, and polyhydroxyalkanoate content, as well as mathematical modelling to investigate how energy derived from sulfur oxidation drives carbon fluxes within the symbiosis and between the holobiont and its habitat. We found that under aerobic conditions without external energy sources only the primary symbiont, Ca. Thiosymbion algarvensis, fixed carbon. This symbiont relied on internal sulfur storage for energy production. Our model showed that the apparent efficiency of carbon fixation driven by sulfur oxidation in the symbiosis was higher than thermodynamically feasible if only stored sulfur was considered as source of energy and reducing equivalents. The model and additional calculations showed that reducing equivalents must be derived from a different source than energy. We identified the large amounts of polyhdroxyalkanoate stored by the symbiont as the likely source of reducing equivalents for carbon fixation in the symbiont which boosts the yield of sulfur-driven carbon fixation. The model also showed that heterotrophic carbon fixation by host tissue is not negligible and has to be considered when assessing transfer of carbon from the symbionts to the host.

microbiology↗

bioRxiv2023

High genetic diversification in a symbiotic marine annelid is driven by microgeography and glaciation

Marine invertebrates with limited dispersal abilities exhibit high levels of genetic divergence among populations. However, the spatial extent of genetic differentiation in these species remains poorly understood because identifying natural barriers to gene flow can be challenging in the marine environment. In this study, we investigated the population genetic structure of the interstitial annelid Olavius algarvensis, a species that lays eggs in its immediate surroundings and does not have an active dispersal phase. We analyzed the mitochondrial and nuclear genome sequences of hundreds to thousands of individuals from eleven sites in the Mediterranean, spanning microgeographic scales of < 5 km to macrogeographic scales of 800 km. Comparisons of single nucleotide polymorphisms (SNPs) in mitochondrial genomes revealed a complex history of introgression events, with as many as six mitochondrial lineages co-occurring in individuals from the same site. In contrast, SNP analyses of nuclear genomes revealed clear genetic differentiation at micro- and macrographic scales, characterised by a significant isolation by distance pattern (IBD). IBD patterns further indicated the presence of a historical physical barrier to gene flow on the east coast of the island of Elba corresponding to the historical shoreline around Elba during the Last Glacial Maximum in the Late Pleistocene, and highlighting the influence of geological forces in shaping population genetic structuring in the species today. Overall, our results provide strong empirical evidence for the high genomic diversification across spatial scales in marine interstitial fauna.

evolutionary biology↗

bioRxiv2023

An intranuclear bacterial parasite of deep-sea musselsexpresses apoptosis inhibitors acquired from its host

Endozoicomonadaceae bacteria are widespread in many marine animals, and generally considered beneficial. Members of one clade, however, Candidatus Endonucleobacter, infect the nuclei of deep-sea mussels, where they replicate to [≥] 80,000 bacteria per nucleus and cause the nuclei to swell to 50 times their original size. How these parasites are able to persist in host nuclei without the cell undergoing apoptosis is not known. We show here that Ca. Endonucleobacter encodes and expresses 7-15 inhibitors of apoptosis (IAPs), proteins previously only known from animals and viruses. Dual RNA-seq transcriptomes of infected nuclei revealed parallel upregulation of Ca. Endonucleobacter IAPs and host caspases, suggesting an arms race between the parasite and host for control of apoptosis. Comparative phylogenetic analyses revealed that Ca. Endonucleobacter acquired IAPs repeatedly through horizontal gene transfer from their hosts in convergent acquisition, possibly mediated by herpes viruses that may infect both the parasite and the host.

microbiology↗

bioRxiv2022

The deep-sea coral, Callogorgia delta, associates with bacteria belonging to a novel marine branch of the Mollicutes

Microbes perform critical functions in corals yet most knowledge is derived from the photic zone. Here, we discovered two mollicutes that dominate the microbiome of the deep-sea octocoral, Callogorgia delta, and reside in the mesoglea. These symbionts were abundant across the hosts range, absent in the water, and rare in sediments. The symbionts lack all known fermentative capabilities including glycolysis and can only generate energy from arginine provided by the coral host. Their genomes feature extensive mechanisms to interact with foreign DNA which may be indicative of their role in symbiosis. We erect the novel family Oceanoplasmataceae which includes these symbionts and others associated with four marine invertebrate phyla. Its exceptionally broad host range suggests that the diversity of this enigmatic family remains largely undiscovered. Oceanoplasmataceae genomes are the most highly reduced among mollicutes providing new insight into their reductive evolution and the roles of coral symbionts.

microbiology↗

bioRxiv2022

De novo phytosterol synthesis in animals

Sterols are lipids that regulate multiple processes in eukaryotic cells, and are essential components of cellular membranes. Sterols are currently assumed to be kingdom specific, with phytosterol synthesis restricted to plants while animals are only able to synthesize cholesterol. Here, we challenge this assumption by demonstrating that the marine annelids Olavius and Inanidrilus synthesize the phytosterol sitosterol de novo. Using multi-omics, high-resolution metabolite imaging, heterologous gene expression and enzyme assays, we show that sitosterol is the most abundant (60%) sterol in these animals and characterize its biosynthetic pathway. We show that phytosterol synthesis partially overlaps with cholesterol synthesis and involves a non-canonical C-24 sterol methyltransferase (C24-SMT). C24-SMT is an essential enzyme for sitosterol synthesis in plants, but not known from animals with bilateral symmetry (bilaterians). Our comparative phylogenetic analyses of C24-SMT homologs revealed that these are widely distributed across annelids and other animal phyla, including sponges and rotifers. Our findings show that phytosterol synthesis and use is not restricted to the plant kingdom, and indicate that the evolution of sterols in animals is more complex than previously assumed.

biochemistry↗

bioRxiv2021

Highly variable fidelity drives symbiont community composition in an obligate symbiosis

Multipartite symbioses, which involve intimate interactions among three or more species, have evolved independently numerous times in convergent evolution, and enable functional complexity and ecological flexibility. How stability is maintained in such relationships remains, however, poorly understood, and can only be fully understood by integrating processes across both micro- and macroevolutionary scales. In this study, we bridge these scales by examining the symbiotic communities of gutless marine oligochaetes - annelid worms that have become obligately dependent on their bacterial partners for nutrition and waste removal over the past 150 million years. Using metagenomic sequencing of 231 individuals from 63 host species, collected across 17 marine environments worldwide, we reconstructed host and symbiont phylogenies to investigate the composition, specificity, and evolutionary history of their symbiotic communities from the strain to genus level. Our results show that each gutless oligochaete harbors up to 10 symbiont species drawn from a restricted pool of 33 marine bacterial genera. Community composition was strongly shaped by host species at 90% explanatory power, and much less by geography or environment. Symbiont communities were highly stable within host species but shifted rapidly at short macroevolutionary scales as host species diverged. Ancestral state reconstructions revealed that the primary symbiont, Candidatus Thiosymbion, was an early and persistent acquisition, while secondary symbionts were gained multiple times through convergent evolution, enhancing the diversity and metabolic flexibility of the symbiotic communities. By linking fine-scale microevolutionary dynamics with broader macroevolutionary patterns, our study reveals how gutless oligochaetes achieve both stability and flexibility in their symbiotic partnerships - enabling long-term host dependency while driving innovation and adaptation. This evolutionary trajectory may underpin the ecological success and diversification of gutless oligochaetes in marine sediments, and may help explain the repeated emergence and persistence of other multipartite associations.

evolutionary biology↗

bioRxiv2021

Fidelity varies in the symbiosis between a gutless marine worm and its microbial consortium

In obligate symbioses, partner fidelity plays a central role in maintaining the association over evolutionary time. Fidelity has been well studied in hosts with only a few symbionts, but little is known about how fidelity is maintained in obligate associations with multiple co-occurring symbionts. Here, we show that partner fidelity varies from strict to absent in a gutless marine annelid and its consortium of co-occurring symbionts that provide it with nutrition. We sequenced the metagenomes of 80 Olavius algarvensis individuals from the Mediterranean, and compared host mitochondrial and symbiont phylogenies based on single nucleotide polymorphisms across genomes, using a low-coverage sequencing approach that has not yet been applied to microbial community analyses. Fidelity was strongest for the two chemoautotrophic, sulphur-oxidizing symbionts that dominated the microbial consortium in all host individuals. In contrast, fidelity was only intermediate to absent in the sulphate-reducing and spirochaetal symbionts, which occurred in lower abundance and were not always present in all host individuals. We propose that variable degrees of fidelity are advantageous for these hosts by allowing the faithful transmission of their nutritionally most important symbionts and flexibility in the acquisition of other symbionts that promote ecological plasticity in the acquisition of environmental resources.

microbiology↗

bioRxiv2020

The hidden pangenome: comparative genomics reveals pervasive diversity in symbiotic and free-living sulfur-oxidizing bacteria

Sulfur-oxidizing Thioglobaceae, often referred to as SUP05 and Arctic96BD clades, are widespread and common to hydrothermal vents and oxygen minimum zones. They impact global biogeochemical cycles and exhibit a variety of host-associated and free-living lifestyles. The evolutionary driving forces that led to the versatility, adoption of multiple lifestyles and global success of this family are largely unknown. Here, we perform an in-depth comparative genomic analysis using all available and newly generated Thioglobaceae genomes. Gene content variation was common, throughout taxonomic ranks and lifestyles. We uncovered a pool of variable genes within most Thioglobaceae populations in single environmental samples and we referred to this as the hidden pangenome. The hidden pangenome is often overlooked in comparative genomic studies and our results indicate a much higher intra-specific diversity within environmental bacterial populations than previously thought. Our results show that core-community functions are different from species core genomes suggesting that core functions across populations are divided among the intra-specific members within a population. Defense mechanisms against foreign DNA and phages were enriched in symbiotic lineages, indicating an increased exchange of genetic material in symbioses. Our study suggests that genomic plasticity and frequent exchange of genetic material drives the global success of this family by increasing its evolvability in a heterogeneous environment.

microbiology↗

bioRxiv2020

Becoming symbiotic - the symbiont acquisition and the early development of bathymodiolin mussels

Symbiotic associations between animals and microorganisms are widespread and have a profound impact on the ecology, behaviour, physiology, and evolution of the host. Research on deep-sea mussels of the genus Bathymodiolus has revealed how chemosynthetic symbionts sustain their host with energy, allowing them to survive in the nutrient-poor environment of the deep ocean. However, to date, we know little about the initial symbiont colonization and how this is integrated into the early development of these mussels. Here we analysed the early developmental life stages of B. azoricus, "B". childressi and B. puteoserpentis and the changes that occur once the mussels are colonized by symbionts. We combined synchrotron-radiation based {micro}CT, correlative light and electron microscopy and fluorescence in situ hybridization to show that the symbiont colonization started when the animal settled on the sea floor and began its metamorphosis into an adult animal. Furthermore, we observed aposymbiotic life stages with a fully developed digestive system which was streamlined after symbiont acquisition. This suggests that bathymodiolin mussels change their nutritional strategy from initial filter-feeding to relying on the energy provided by their symbionts. After [~]35 years of research on bathymodiolin mussels, we are beginning to answer fundamental ecological questions concerning their life cycle and the establishment of symbiosis.

zoology↗

bioRxiv2020

Deep-sea mussels from a hybrid zone on the Mid-Atlantic Ridge host genetically indistinguishable symbionts

The composition and diversity of animal microbiomes is shaped by a variety of factors, many of them interacting, such as host traits, the environment, and biogeography. Hybrid zones, in which the ranges of two host species meet and hybrids are found, provide natural experiments for determining the drivers of microbiome communities, but have not been well studied in marine environments. Here, we analysed the composition of the symbiont community in two deep-sea, Bathymodiolus mussel species along their known distribution range at hydrothermal vents on the Mid-Atlantic Ridge, with a focus on the hybrid zone where they interbreed. In-depth metagenomic analyses of the sulphur-oxidising symbionts of 30 mussels from the hybrid zone, at a resolution of single nucleotide polymorphism analyses of [~]2500 orthologous genes, revealed that parental and hybrid mussels have genetically indistinguishable symbionts. While host genetics does not appear to affect symbiont composition in these mussels, geographic location of the mussels on the Mid-Atlantic Ridge explained 45 % of symbiont genetic variability based on redundancy analyses. We hypothesize that geographic structuring of the free-living symbiont population plays a major role in driving the composition of the microbiome in these deep-sea mussels.

microbiology↗

bioRxiv2020

Kentrophoros magnus sp. nov. (Ciliophora, Karyorelictea), a new flagship species of marine interstitial ciliates

The karyorelictean ciliate Kentrophoros lacks a defined oral apparatus but has a dense coat of symbiotic bacteria that it consumes by phagocytosis. Body size, shape, and nuclear characters are variable in this genus. We formally describe a new species, K. magnus from Elba (Italy), which has unusual folding of its symbiont-bearing surface into pouch-like compartments, a body form that we term "pseudotrophosomal". K. magnus cells are large (2100 {+/-} 700 x 170 {+/-} 23 m in vivo), but contain only one micronucleus and two macronuclei, although these are much bigger than other Kentrophoros (widths 20 {+/-} 2.5 and 31 {+/-} 4.0 m respectively in K. magnus). We also present morphological observations on a close relative from Twin Cayes (Belize), which also has relatively large nuclei (micronuclei 13 {+/-} 1.5 m, mature macronuclei 20 {+/-} 2.8 m), but unlike K. magnus, it has on average 22 nuclei per cell, with different developmental stages of the macronuclei present simultaneously, and lacks pouch-like folding. Nuclear number and arrangement are important characters for karyorelicts. We suggest the use of a "nuclear formula" to simplify descriptions. Our discovery of large and morphologically distinctive new species underlines the incompleteness of our knowledge about meiofaunal ciliates.

microbiology↗

bioRxiv2020

Deep-sea corals near cold seeps associate with chemoautotrophic bacteria that are related to the symbionts of cold seep and hydrothermal vent mussels.

Cnidarians are known for their symbiotic relationships, yet no known association exists between corals and chemoautotrophic microbes. Deep-sea corals, which support diverse animal communities in the Gulf of Mexico, are often found on authigenic carbonate in association with cold seeps. Sulfur-oxidizing chemoautotrophic bacteria of the SUP05 cluster are dominant symbionts of bathymodiolin mussels at cold seeps and hydrothermal vents around the world and have also been found in association with sponges. Therefore, we investigated whether other basal metazoans, corals, also associate with bacteria of the SUP05 cluster and report here that such associations are widespread. This was unexpected because it has been proposed that cnidarians would not form symbioses with chemoautotrophic bacteria due to their high oxygen demand and their lack of specialized respiratory structures. We screened corals, water, and sediment for SUP05 using 16S metabarcoding and found SUP05 phylotypes associated with corals at high relative abundance (10 - 91%). These coral-associated SUP05 phylotypes were coral host specific, absent in water samples, and rare or not detected in sediment samples. The genome of one SUP05 phylotype associated with Paramuricea sp. type B3, contained the genetic potential to oxidize reduced sulfur compounds and fix carbon and these pathways were transcriptionally active. Finally, the relative abundance of this SUP05 phylotype was positively correlated with chemoautotrophically-derived carbon and nitrogen input into the coral holobiont based on stable carbon and nitrogen isotopic compositions. We propose that SUP05 may supplement the diet of its host coral through chemoautotrophy or may provide nitrogen, essential amino acids, or vitamins. This is the first documented association between a chemoautotrophic symbiont and a cnidarian, broadening the known symbioses of corals and may represent a novel interaction between coral communities and cold seeps.

microbiology↗

bioRxiv2019

Seagrass excretes sugars to their rhizosphere making them the sweet spots in the sea

Seagrasses are one of the most efficient sinks of carbon dioxide on Earth1: They bury carbon 35 times faster than tropical rainforests on a per unit area basis2. While we know that carbon sequestration in terrestrial plants is intimately linked to the microorganisms living in their soils3-6, the interactions of seagrasses with their rhizospheres are poorly understood. We show that three seagrass species from two oceans excrete simple sugars, mainly sucrose, into their rhizosphere that accumulate to over 200 {micro}M. Such high concentrations are at least 80 times higher than previously observed in the ocean, and surprising, as sugars are quickly consumed by microorganisms. In situ analyses and incubation experiments indicated that phenolic compounds from the seagrass inhibited microbial consumption of sucrose. Metagenomic and metatranscriptomic analyses of the microbial communities in the seagrass rhizosphere revealed that many members had the genes for degrading sucrose, but these were only expressed by a few specialists that also expressed genes for degrading phenolics. Our results explain why sucrose accumulates under seagrass meadows, where it comprises as much as 40% of the dissolved organic carbon. Destruction of extant seagrass canopies would allow sediment microorganisms to consume the tremendous deposits of sucrose buried underneath their meadows, thereby releasing large amounts of CO2 into the oceans and atmosphere.

microbiology↗

bioRxiv2019

Horizontal acquisition followed by expansion and diversification of toxin-related genes in deep-sea bivalve symbionts

Deep-sea bathymodioline mussels gain their nutrition from intracellular bacterial symbionts. Their sulfur-oxidizing (SOX) symbionts were recently shown to encode abundant toxin-related genes (TRGs) in their genomes, which may play a role in beneficial host-microbe interactions. Here, we compared TRGs in the genomes of SOX symbionts from 10 bathymodioline mussel and two sponge species to better understand their potential functions and evolutionary origins. Despite the close phylogenetic relatedness of these symbionts, the number and classes of encoded toxins varied greatly between host species. One of the TRG classes, YDs, has experienced gene expansions multiple times, suggesting that these genes are under adaptive selection. Some symbiont genomes contained secretion systems, which can play a role in host-microbe interactions. Both TRGs and secretion systems had a heterogeneous distribution, suggesting that these closely related bacteria have acquired different molecular mechanisms for interacting with the same family of animal hosts, possibly through convergent evolution.

microbiology↗