Fine-scale thermal heterogeneity within intertidal and subtidal microhabitats could drive divergence in organismal heat tolerance. Reef corals from the extreme intertidal may hold optimism for the future of coral reefs and give insights into the mechanisms by which coral may persist under future conditions. Here, we compared the thermal sensitivities of intertidal and subtidal Acropora digitifera and evaluated their bleaching phenotypes, transcriptomes, host genetic differentiation and bacterial communities. Results showed that only heat-exposed subtidal corals displayed significantly reduced photochemical efficiency, symbiont densities, pigment and host protein concentrations, suggesting bleaching and host starvation. Despite being genetically similar, heat-exposed subtidal corals mounted stronger immune activation and amino acid degradation but downregulated monocarboxylate transport and calcification compared to intertidal corals. In contrast to the prevalence of Cladocopium in subtidal corals, intertidal corals were dominated by Durusdinium, whose transcriptional signature was characterised by lineage-specific and constitutively high transcript abundance of orthologs involved in stress response, metabolism, photosynthesis, cell cycle and symbiotic interactions. Furthermore, 16S rRNA sequencing demonstrated an origin-dependent bacterial composition, with Endozoicomonas being more abundant and important in co-occurrence networks of intertidal corals. Our findings suggest that distinction in Symbiodiniaceae and bacterial communities and Symbiodiniaceae lineage-specific transcriptional footprint largely underpin the exceptional thermotolerance of intertidal Acropora. Although these corals provide promising avenues for restoration, such a mechanism may bring attention to the risk of using them in selective breeding, particularly given the horizontal transmission of algal symbionts in Acropora.

Horizontal transmission of white spot syndrome virus (wssv) from Procambarus clarkii to Eriocheir sinensis in polyculture systems: Infection characteristics, physiological responses, and ecological impacts

ABSTRACT Frequent outbreaks of eel “mucus sloughing and hemorrhagic septicemia disease” caused by Anguillid herpesvirus 1 (AngHV) are a major epidemic in both wild and farmed eels. This virus has garnered global attention due to heavy losses on eel farms and the lack of protective vaccines or effective drugs, highlighting the urgent need for potent antiviral agents. In this study, we revealed a hepcidin homolog LJ-hep2 from Japanese seabass (Lateolabrax japonicus) can bind to AngHV and impede viral entry into cells. LJ-hep2 could directly destroy the viral envelope and showed a higher anti-AngHV activity than AA-hep (a hepcidin homolog cloned from Anguilla anguilla). It was found that the destruction of viral structure by LJ-hep2 was related to the binding of the peptide to AngHV envelope protein ORF51, and the two amino acid residues at the N-terminus of the peptide (lysine and phenylalanine) might play a key role. Comparative antiviral experiments with mutated LJ-hep2 (LJ-hep2A4A5) and multi-species hepcidin further confirmed this finding and demonstrated that these two amino acids were indispensable in the inhibition of AngHV infection by LJ-hep2. In an established eel immersion infection model, LJ-hep2 treatment reduced viral accumulation in tissues, inhibited horizontal transmission, alleviated skin lesions, and improved eel survival. Taken together, this study suggests that LJ-hep2 could inhibit AngHV infection in vitro and in vivo, and identify ORF51 as a potential target for the development of anti-AngHV drugs.

As a persistent-propagative plant virus, Rice stripe virus (RSV) relies on specific interactions between viral proteins and components of its vector, the small brown planthopper (SBPH), for its efficient replication and transmission. To identify vector factors involved in this process, we employed GST pull-down/MS to screen SBPH proteins that interact with RSV P3, a key nonstructural protein for virus transmission, and obtained 55 candidate proteins. Among these, Purα was selected for further investigation. A direct interaction between P3 and Purα was confirmed by co-immunoprecipitation (Co-IP). Confocal microscopy revealed extensive colocalization of Purα and P3 in the cytoplasm of Sf9 cells and critically, within key SBPH tissues for virus transmission, including the midgut, salivary glands, and ovaries. Functional studies showed that knocking down Purα via RNA interference (RNAi) inhibited viral accumulation in SBPHs, consequently reducing both horizontal and vertical transmission efficiency. Our results provide compelling evidence that RSV hijacks the vector protein Purα to promote viral accumulation within the insect body, thereby facilitating transmission. These findings deepen our understanding of plant virus-vector interactions and reveal a potential target for developing novel strategies to control virus spread.

Protocol for spatial sampling and monitoring infection disease dynamics and pathogen spread in social ambrosia beetle colonies.

Approximately 85% of stony coral species initially acquire their nutritional symbionts (Family Symbiodiniaceae) from the environment (horizontal transmission). Recent studies have identified live Symbiodiniaceae cells in the feces of coral-eating (corallivorous) and herbivore/detritivore fish, and thus these fish could vector Symbiodiniaceae to prospective stony coral hosts. However, nearly all data on viable Symbiodiniaceae cell densities in fish feces are from Pacific reefs. This study quantifies the density and diversity of viable Symbiodiniaceae cells in the feces of six Caribbean corallivore and herbivore/detritivore fish species in the U.S. Virgin Islands, enabling comparisons of consumer-symbiont pathways between ocean basins. Caribbean fish feces contained an average of 5 million viable Symbiodiniaceae cells ml-1, comparable to previously reported values for Pacific corallivores. However, unlike on Pacific reefs, where Symbiodiniaceae cell densities varied in feces by fish trophic group, in the Caribbean, high densities of Symbiodiniaceae cells were documented in fish feces across feeding categories. In Caribbean herbivore/detritivore feces, high Symbiodiniaceae densities likely reflect observed, yet unexpected, feeding by these fishes on corals. Contributions of sloughed diseased coral tissue to detritus on U.S. Virgin Islands reefs may have also increased the number of Symbiodiniaceae cells consumed by detritivorous fishes. Symbiodiniaceae genera Symbiodinium, Breviolum, Cladocopium, Durusdinium, and Fugacium were detected in Caribbean fish feces. These findings demonstrate that corallivore and herbivore/detritivore fish feces constitute environmental hotspots of viable Symbiodiniaceae on Caribbean reefs.

The high mutation rates of RNA virus replication generate genetically diverse virus variants in infected hosts. However, the effects of mutations on viral fitness and adaptability remain understudied in fungal-virus pathosystems. In this study, a novel hypovirus (single-stranded positive-sense RNA genome, family Hypoviridae), designated Valsa pyri hypovirus 1-α (VpHV1-α), and two of its shorter, less prevalent variants (VpHV1-β and VpHV1-γ), that contain different internal deletions in the N-terminal coding region of the viral protein, were identified in phytopathogenic Valsa pyri fungal strains. Repeated subculture of a fungal strain infected with VpHV1-α produced VpHV1-β and VpHV1-γ, demonstrating that VpHV1-β and VpHV1-γ were generated by the deletion of the VpHV1-α genome. Compared to VpHV1-α and VpHV1-β, VpHV1-γ, which has a larger deletion, attenuated fungal growth and pathogenicity while accumulating to higher levels. However, it exhibited lower vertical transmission efficiency through spores. Intriguingly, unlike VpHV1-α and VpHV1-β, VpHV1-γ showed restricted horizontal transmission via hyphal anastomosis. This restriction was associated with the induction of programmed cell death and transcriptional activation of vegetative incompatibility-related genes upon VpHV1-γ infection. Additionally, VpHV1-γ infection upregulated key components of RNA silencing (AGO3 and DCL2). Our results reveal a trade-off between viral accumulation and transmission efficiency, influencing the spread and persistence of VpHV1 variants in fungal populations. These findings provide new insights into viral evolution and host adaptation in natural fungal-virus ecosystems.IMPORTANCEStudies on mycoviruses are significant for advancing our understanding of viral evolution and host-pathogen interactions. In this study, we identified and characterized a novel hypovirus (VpHV1) infecting the plant-pathogenic fungus Valsa pyri. VpHV1 exists as three viral variants (α, β, and γ). Notably, the γ variant, the least prevalent and shortest due to an internal genomic deletion, exhibited unique phenotypic traits: enhanced viral accumulation and symptom severity but impaired horizontal and vertical transmission. Intriguingly, infection by the γ variant induces programmed cell death during hyphal anastomosis with an isogenic fungal strain, thereby preventing viral transmission. This vegetative incompatibility-like reaction may represent a previously unknown defense mechanism in filamentous fungi, functioning to restrict viral spread within genetically homogeneous populations. Our findings demonstrate that transmission ability is a critical selective factor in viral evolution and adaptation within host populations.

Acinetobacter baumannii carrying the blaNDM-1 gene, which encodes New Delhi metallo-β-lactamase-1 (NDM-1), exhibits resistance to nearly all β-lactams and is not affected by β-lactamase inhibitors, limiting treatment options. The blaNDM-1 gene is often associated with other antimicrobial resistance (AMR) genes, resulting in multidrug-resistant (MDR) phenotypes. We previously reported a large, circa (ca.) 170 kb plasmid co-harbouring blaNDM-1- and blaOXA-58-encoded carbapenemases in clinical MDR Acinetobacter nosocomialis and A. baumannii isolates from a tertiary hospital in Terengganu, Malaysia, in 2015 and 2016, respectively. In this study, we identified four additional MDR A. baumannii isolates from the same hospital (2018–2020) carrying blaNDM-1 on a similar plasmid. Complete genome sequences were obtained using a hybrid assembly of short-read DNA Nanoball Sequencing(DNBSeq) and long-read (Oxford Nanopore Technologies) data. All isolates belonged to distinct, unrelated clonal lineages, indicating the ongoing horizontal transmission of this plasmid. Comparative analysis revealed substantial structural variability among the plasmids, largely driven by insertion sequence elements and mobile xrs (also known as pdif) modules. In two A. baumannii isolates (i.e. AC1932 and AC2014), blaOXA-58 and several adjacent xrs modules were absent. Despite this, carbapenem minimum inhibitory concentrations remained comparable across all isolates, strongly indicating that blaNDM-1 is the primary carbapenem resistance determinant. Notably, in A. baumannii AC1839, we identified a 15,434 bp presumptive transposon carrying a type III cyclic oligonucleotide-based anti-phage signalling system, inserted within the xrs-rich region of the plasmid. AC1839 also carried a separate 11.1 kp plasmid carrying the tetracycline resistance genes tetA(39)-tetR within an xrs module. Identical xrs modules were identified in other unrelated Acinetobacter plasmids. These results underscore the mobility and potential roles of xrs modules in AMR gene dissemination and, more generally, in shaping Acinetobacter plasmid evolution.

Hepatitis B remains a global health concern. Achieving the World Health Organization’s (WHO) goal of eliminating the disease by 2030 requires a comprehensive understanding of its transmission dynamics. This study aimed to develop and apply an extended SIVRM (Susceptible–Infected–Vaccinated–Recovered–Mortality) model to simulate hepatitis B transmission in Indonesia and to evaluate optimal vaccination strategies. The model comprises 14 compartments that distinguish between vertical and horizontal transmission, account for vaccination and loss of immunity, and incorporate hepatitis B virus (HBV) reactivation among recovered individuals, a novel feature of this model. Parameters were estimated using data from the Social Security Administrator for Health (BPJS Kesehatan) from 2019 to 2023 through a least-squares fitting approach. The basic reproduction number () and disease-free equilibrium (DFE) were analytically derived. Simulations were conducted using MATLAB 2018 to project hepatitis B trends from 2024 to 2030 and to evaluate scenarios of adult and newborn vaccination coverage. A key finding from the parameter estimation was an HBV reactivation rate of 0.30, indicating that 30% of recovered individuals remain at risk. The model estimated a baseline of 4.39, indicating that current control strategies in Indonesia are insufficient to achieve the WHO elimination goal. However, scenario-based analysis revealed that increasing adult vaccination coverage to at least 59%, while maintaining newborn vaccination at 70%, could reduce to 0.90 and substantially lower the disease burden. These findings underscore the urgent need to expand adult vaccination programs and strengthen post-recovery monitoring to advance hepatitis B elimination in Indonesia.

Human immunodeficiency virus (HIV) infection in children is usually vertically acquired from the mother, in utero, intrapartum, or via breastfeeding. In this case, we report the probable case of horizontal transmission of HIV between two siblings. Based on the available clinical and laboratory data, perinatal, sexual, and health care-related transmission are unlikely. Although rare, this method of transmission needs to be recognized, especially in the setting of direct contact with an individual with poorly suppressed HIV viral infection.

ABSTRACTBackgroundCurrent international guidelines lack clear recommendations on the management of non‐colonised patients undergoing intra‐hospital transfer from the ward in which horizontal transmission of Candida auris is known to occur (defined as endemic for Candida auris) to wards with no horizontal transmission detected (defined as non‐endemic wards), particularly regarding the timing and number of screening swabs needed to exclude colonisation.MethodsSingle‐center prospective observational study at a tertiary‐care hospital in Genoa, Italy, including adults transferred from the C. auris endemic‐ICU (eICU) to non‐endemic wards between January and December 2024. Patients who tested negative for C. auris colonisation both at eICU admission and at transfer, and who had ≥ 1 screening swab performed post‐transfer, were included. Swabs (bilateral axilla/groin) were performed on Days 0–1, 2–3 after transfer, and then weekly, and tested for C. auris with real‐time PCR. Patients were considered sufficiently screened to exclude colonisation if they underwent ≥ 2 swabs within the first 4 weeks after transfer.ResultsAmong 462 patients transferred from the eICU, 440 (95.2%) were non‐colonised. Among them, 275 (62.5%) met inclusion criteria, and 208 (75.6%) were considered sufficiently screened. C. auris colonisation was detected in 34/208 (16.3%) patients, with 21 (61.8%) positive in the first post‐transfer swab. Among 99 patients who had a negative result of a swab performed within 1 day before transfer, 7 (7.1%) resulted later positive. C. auris candidemia occurred in 4/34 (11.8%) patients with colonisation detected post‐transfer, compared to 1/35 (2.9%) patients found colonised during eICU stay, and none occurred in non‐colonised individuals.ConclusionsA single negative screening test at eICU discharge is insufficient to exclude colonisation, even if performed within 24 h from transfer. Repeated screening, ideally within the first 2 weeks post‐transfer, is essential to detect colonisation and prevent further C. auris transmission.

Carbapenem-resistant Enterobacterales (CRE) frequently cause serious, life-threatening infections with limited treatment options. The most common mechanism of carbapenem resistance is carbapenemase production. Colombia is considered endemic for KPC, while metallo-β-lactamases such as NDM and VIM are increasingly circulating. An emerging concern is the appearance of strains harbouring more than one carbapenemase. Here, we report a sentinel Enterobacter hormaechei isolate, highly resistant to β-lactams and co-harbouring three carbapenemases. Enterobacter hormaechei was isolated from the wound of a 22-year-old male and molecularly characterized to decipher its resistance profile. Multiplex real-time PCR was used to screen for carbapenemases. Long-read WGS was performed using ONT MinION™, the genome was assembled de novo and resistome and plasmid types were analysed. Conjugation experiments were performed using E. coli J53-AzR as a recipient. Multiplex PCR revealed the presence of bla KPC, bla VIM, and bla NDM. Conjugation experiments yielded bla KPC, and bla KPC-bla VIM-bla NDM transconjugants, suggesting two distinct plasmids. WGS confirmed that bla KPC-2 was encoded on a 58 Kb IncN plasmid, while bla VIM-24 and bla NDM-1 were carried by a 370 Kb multi-replicon plasmid (IncR-IncFII-IncC). Although the emergence of triple-carbapenemase producers has been reported, it remains rare. However, sentinel isolates as the one described here (KPC-VIM-NDM) are extremely worrisome since dissemination of multiple carbapenemases could occur via conjugative plasmids in addition to horizontal gene transmission via mobile genetic elements. Considering that Colombia has long been considered a KPC-endemic country, the findings described here call for a thorough epidemiological surveillance to assess the real frequency of Enterobacterales carrying multiple carbapenemases.

The spatial distributions of host-associated (HA) microbes are shaped by the spatial processes of environmental selection and dispersal. However, unlike free-living organisms, HA microbes experience selection and dispersal at two separate spatial scales – the scale of the microbes and the scale of their hosts. Therefore, HA microbes must tolerate both the environment created by their host (microbe-scale environment) and the environment in which their host resides (host-scale environment). Likewise, HA microbes can disperse both between hosts through horizontal or vertical transmission (microbe-scale dispersal) and between locations through host movement (host-scale dispersal). In this paper, we examine how host- and microbe-scale spatial processes contribute to the spatial distribution of Wolbachia endosymbionts in Aphaenogaster fulva-rudis-texana (Hymenoptera: Formicidae) complex ants from Great Smoky Mountains National Park. We begin by identifying significant spatial variation in Wolbachia relative abundance at both the host (across the landscape) and microbe (across host lineages) scales. We then demonstrate a correlation between host- and microbe-scale environmental selection, complicating efforts to isolate the independent effects of host- versus microbe-scale processes. To overcome this challenge, we leverage both the broad distributions of individual host lineages across different environments and sites of co-occurrence between different host lineages within the same environments. This allows us to assess how both host- and microbe-scale processes contribute to spatial variation in our system. Ultimately, our results shed light on the myriad of interacting factors governing spatial variation in HA microbes and why spatial variation in HA microbes is more challenging to understand than spatial variation in free-living organisms.

This study investigates how attitudes and behaviours are transmitted across generations and social networks, focusing on the relative influence of parents, grandparents, and peers. Building on the influential work of Cavalli-Sforza and Feldman (1982), we aimed to disentangle vertical and horizontal pathways of cultural transmission and assess their contribution to the stability and variation of cultural traits in a contemporary population. We conducted a large-scale survey involving 1905 university students in Australia and 4000 of their parents, grandparents, and friends. Participants reported their attitudes and behaviours across domains such as religiosity, politics, environmentalism, health, and leisure. Responses were analysed using factor analysis, path modelling, correlational analysis, and simulations based on additive transmission models. Our results show that cultural resemblance is strongest for religiosity, political orientation, environmentalism, and health behaviours. These traits exhibited clear vertical transmission from parents to children, with additional indirect influence from grandparents. Peer similarity was also evident, suggesting horizontal transmission and/or peer selection. Traits such as media use, music, and reading habits showed weaker familial resemblance and appeared more influenced by non-familial or contextual factors. Simulations confirmed that cultural traits are more likely to be adopted when shared by both parents and peers, though for some traits (especially left-wing political views and non-religiosity) external influences predominated. The findings demonstrate that cultural transmission is domain-specific and shaped by both family structure and social networks. Vertical and horizontal pathways contribute jointly, but their strength varies by trait. These results underscore the importance of integrating biological, psychological, and sociocultural factors to understand the persistence and evolution of beliefs and behaviours over generations.

This study investigates how attitudes and behaviours are transmitted across generations and social networks, focusing on the relative influence of parents, grandparents, and peers. Building on the influential work of Cavalli-Sforza and Feldman (1982), we aimed to disentangle vertical and horizontal pathways of cultural transmission and assess their contribution to the stability and variation of cultural traits in a contemporary population. We conducted a large-scale survey involving 1905 university students in Australia and 4000 of their parents, grandparents, and friends. Participants reported their attitudes and behaviours across domains such as religiosity, politics, environmentalism, health, and leisure. Responses were analysed using factor analysis, path modelling, correlational analysis, and simulations based on additive transmission models. Our results show that cultural resemblance is strongest for religiosity, political orientation, environmentalism, and health behaviours. These traits exhibited clear vertical transmission from parents to children, with additional indirect influence from grandparents. Peer similarity was also evident, suggesting horizontal transmission and/or peer selection. Traits such as media use, music, and reading habits showed weaker familial resemblance and appeared more influenced by non-familial or contextual factors. Simulations confirmed that cultural traits are more likely to be adopted when shared by both parents and peers, though for some traits (especially left-wing political views and non-religiosity) external influences predominated. The findings demonstrate that cultural transmission is domain-specific and shaped by both family structure and social networks. Vertical and horizontal pathways contribute jointly, but their strength varies by trait. These results underscore the importance of integrating biological, psychological, and sociocultural factors to understand the persistence and evolution of beliefs and behaviours over generations.

Amdoparvoviruses are best known as agents of disease in carnivorans, but here we provide the first in-depth molecular evolutionary and ecological information for an amdoparvovirus in wild rodents (field voles, Microtus agrestis). We applied an RNA-sequencing approach in lung tissue that yielded high diagnostic sensitivity and multiple full or near-full coding sequences for the new virus (field vole amdoparvovirus, FVAV) in individual voles. FVAV is most similar to amdoparvoviruses in European foxes and wildcats. We present evidence that FVAV is an exogenous, endemic, high-prevalence infection with a short-term history of horizontal transmission and recombination within voles and arising from an ancestral background of dynamic host usage and inter-lineage recombination. FVAV molecular structures involved in host exploitation share a highly conserved functional and evolutionary pattern with those in other amdoparvoviruses. The more variable regions within these structures evolve principally by apparently neutral processes and FVAV within-population mutation distribution mirrors that across the Amdoparvovirus phylogeny. Nonetheless, we did find some evidence of adaptive selection in the most variable regions and we also found convergent host-specific features in the modelled capsid protein of divergent arvicoline-associated lineages that might tend to restrict host range and support that FVAV is a vole-specialist. Increasing FVAV expression was associated with pulmonary inflammation and suppressed splenic T-cell activation, consistent with a potential to drive disease processes as in other amdoparvoviruses. Importantly, our approach highlights the de novo sequence assembly of viral RNA products from shotgun sequencing of rRNA-depleted RNA from tropic tissues in individual hosts as a sensitive and robust means of detecting and characterising not only RNA viruses but also DNA viruses.

Native bacterial endosymbionts in aphids have been studied for many years but it is only recently that transinfections across species are being investigated from an applied perspective. Here we consider the impact of a Rickettsiella viridis transinfection originally from the pea aphid Acyrthosiphon pisum, in an important pest of cereals, Rhopalosiphum padi, that causes feeding damage and transmits barley yellow dwarf virus (BYDV). Our main aims were to quantify the fitness and dispersal consequences of the transinfection, assess its transmission dynamics, and determine whether Rickettsiella influences BYDV acquisition or transmission. The transinfected strain had fitness costs in its new aphid host, with an intrinsic rate of increase (rm) value around 20% lower, and showed horizontal transmission. Rickettsiella did not transmit vertically with complete fidelity, although it persisted in population cages for at least 11 weeks. Although Rickettsiella did not affect transmission of BYDV, it reduced the production of alates by 10% or more depending on aphid density. Aphids carrying Rickettsiella showed a slower rate of movement to adjacent plants compared with those without Rickettsiella. The body colour of aphids with Rickettsiella was also darker. This Rickettsiella transinfection imposes deleterious host effects, while retaining the capacity to persist in populations through horizontal transmission. Although it does not influence BYDV transmission, the reduced alate formation and slower movement suggest potential impacts on pest spread and population structure. These findings advance our understanding of symbiont-host interactions and highlight the potential for endosymbiont manipulations to influence aphid ecology and management. © 2026 Society of Chemical Industry.

Abstract Feather mites require effective dispersal strategies to colonize new hosts. In most birds, these mites are transmitted vertically from parents to offspring. However, in obligate brood parasites like the Cuculus canorus (Common Cuckoo), vertical transmission of cuckoo-specific feather mite species is unlikely because offspring have no contact with their biological parents. We hypothesized that cuckoo-specific feather mites disperse horizontally through physical contacts during the breeding season, such as copulation or male-male competition. If this is the case, yearling cuckoos—with limited breeding experience—should carry fewer mites than adults. To test this prediction, we examined age-related differences in feather mite load and prevalence in common cuckoos, and assessed how these patterns are influenced by host-related and external factors. For this purpose, we captured cuckoos during the breeding season and examined their wing and tail feathers for mites through visual inspection and photography. In addition, mites were collected from a subset of captured birds for identification. Of the two identified mite species, Coraciacarus cuculi was dominant, whereas Scutalges sp. was rare. As predicted, yearlings harbored significantly fewer mites than adults, supporting horizontal transmission as the primary dispersal mode, and mite load tended to increase gradually during the breeding season. In contrast, mite prevalence was similar between age groups, but increased over the breeding season and was higher in male cuckoos than in females, possibly due to distinctive breeding strategies of the common cuckoo. These findings highlight an unconventional dispersal strategy in feather mites associated with brood parasitic birds and provide new insights into parasite transmission dynamics in avian systems.

Microbes are integral players in plant–insect networks, and play crucial roles in host health and ecological interactions. However, the horizontal microbial transmission dynamics via flowers remain insufficiently understood, particularly in hub plants visited by diverse insect communities. Here, using 16S rRNA gene and ITS2 metabarcoding, we characterized the bacterial and fungal communities associated with open flowers, insect-excluded bagged flowers, and flower buds of bramble (Rubus spp.), a highly insect-visited hub plant. Our results show that environmental deposition and insect visitation significantly altered floral microbiota diversity and microbial load, particularly for bacterial communities. Insect visitation potentially enriched fermentative and probably also pathogenic bacteria, including Spiroplasma. While bagged flowers and open flowers both showed high within-group variation for bacterial communities, the microbial networks were more internally connected in bagged flowers, and more centralized in open flowers. The distinct network properties might be due to flower group-specific microbial hub genera introduced by different horizontal transmission routes. Moreover, cross-domain network analysis revealed hub genera unique to bacteria-fungi interactions, including Cladosporium, which was consistently detected across all flower groups. These findings highlight the dominant role of insect visitation in shaping floral microbiota and underscore the ecological significance of hub plants in horizontal microbial transmission across plant–pollinator networks.Supplementary InformationThe online version contains supplementary material available at 10.1186/s40793-026-00853-3.

Atkinsonella hypoxylon virus (AhV) is a fungi-infecting betapartitivirus and the typical member of the Partitiviridae, a family of persistent viruses that infect a broad range of organisms. Partitiviruses have been largely overlooked following their designation as cryptic viruses. However, evidence is accumulating that they play an important role in the ecology of their hosts. Since the capsid proteins of partitiviruses have been implicated in virus–host interactions, exploring their structural biology may give clues into the evolution, horizontal transmission and host adaptation of partitiviruses. The capsid of AhV shares the same organization of other partitiviruses with 60 dimeric capsid protein protomers arranged with T=1 icosahedral symmetry. The structure, determined by cryo-electron microscopy to 2.4 Å, shows that AhV has a unique iteration on the protrusion domain with an extensive network of hydrophobic interactions among equivalent interdigitating loops at the dimerization interface. AhV also shares a conserved helical core in the shell domain, which we extend to all genera of the recognized partitiviruses using protein structure prediction. The helical core appears to be a conserved element of the picobirnavirus lineage of capsid protein folds and provides a template onto which various elaborations of the protrusion domain have evolved. The involvement of the protrusion in virus–host interactions has previously been proposed, and our findings provide evidence of a structural device enabling capsid protein diversification during the evolution of the Partitiviridae.