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Duplouy, A.

Publications and source records attributed to Duplouy, A..

11 recordsLinked to original sources

Bee phylosymbiosis: the relative importance of host phylogeny, behavioral traits, and environment

Phylosymbiotic studies investigate how microbiomes recapitulate their host phylogeny and can thus reveal the evolution of host-microbe relationships. In bees, the extent of phylosymbiosis and its relationship with host ecological traits remain unclear. We integrated public bee 16S rRNA metabarcoding data to investigate how host phylogeny and ecological traits affected the bacterial community associated with 178 bee species. Our results highlight only moderate phylosymbiosis patterns in bees, with the corbiculates associated with diverse lineage-specific microbial communities, while the non-corbiculates were predominantly associated with Wolbachia. Across all bee taxa, Wolbachia was also consistently negatively associated with Lactobacillus. Finally, our analysis revealed that the host ecological traits had only marginal effects on microbial composition. Although eusocial bees harbored distinct microbiomes, the effect of social behavior was confounded by host phylogeny. Climate showed no general effect across bee taxa, but within some genera, microbiomes were more homogeneous among bees from arid and semi-arid regions than among those from other climatic regions. Together, our findings reveal that broad-scale patterns in bee microbiomes emerge primarily as lineage-specific host-microbe associations, with ecological traits acting only weakly and often at a taxon-specific level.

microbiology↗

Meta2Data: Automated data processing for large scale microbiome data re-analysis

Meta2Data is a modular, largely automated pipeline implemented in Python and Bash for the retrieval, standardization, and processing of public microbiome sequencing data. It retrieves metadata from major public repositories, including INSDC and CNCB, using user-provided keywords or BioProject/BioSample identifiers. Retrieved metadata are standardized using a synonym dictionary and then subjected to manual curation. Based on the curated metadata, Meta2Data downloads the corresponding raw sequencing data and processes them using standardized workflows based on DADA2 or VSEARCH. The pipeline supports both single- and multiple-target-region datasets and produces integrated feature tables, taxonomic assignments, and phylogenetic trees for downstream microbial community analyses. Availability and ImplementationMeta2Data is freely available at https://github.com/LinyangSun/Meta2Data and archived on Zenodo at https://doi.org/10.5281/zenodo.20670433

bioinformatics↗

A meta-analysis on the effects of pollutants on the earthworm microbiota

Like for many other organisms, earthworms host a microbiota consisting of bacteria, fungi and other micro-organisms originating from their surrounding environment. In earthworms, these microbes, either associated with the gut, skin, kidney-like nephridia, gizzard or cocoons, aid their hosts with the digestion of organic matter, immune responses against pathogens, and/or detoxification. Unfortunately, pollution is an increasing threat to soil health and soil biodiversity, and numerous articles have characterized both the microbial communities associated with earthworms, as well as the effects of soil pollution on these microbial communities. Here, we aim to synthesize data from across 159 articles to identify consistent global patterns and gaps in the study of earthworms' microbial communities. Additionally, we combined 16S rRNA metabarcoding data from almost 30 articles in a meta-analysis to evaluate the changes in the diversity of earthworm's and surrounding soil's bacterial microbiota after pollutant exposure. Through an evidence map, we clearly showed that most of the earthworm microbiota data came from the Eisenia fetida species reared in laboratory conditions, and only a handful of studies sequenced fungi (ITS) and protists (18S rRNA) in addition to bacteria and archaea (16S rRNA). The scarcity of studies from wild populations, environmental conditions, and the low microbial diversity targets and sources, cannot support a comprehensive view on earthworm's microbial ecology. Nonetheless, results of the meta-analysis indicate that the data did not support the occurrence of significant changes in the microbiota richness and diversity as result of pollution exposure. However, the microbial communities altered their composition, becoming more dissimilar. We suspect the microbiota response to pollution to be host-species specific, but the lack of data severely limited our ability to further elucidate the effect of pollution on earthworm microbiota.

ecology↗

The microbiota of a wild butterfly species over three decades of climate change

Thermal stress can disturb microbial communities associated with host species. As microbes can support essential functions related to host metabolism, physiology, nutrition and immunity, changes in microbial communities can have severe fitness consequences for the host. Although the effects of thermal conditions on host-associated microbiomes have been demonstrated in controlled laboratory settings, how climate change might affect the structure and functionality of microbial communities in wild populations remain poorly understood. Here, we took advantage of the well-characterized long-term field survey of the Glanville fritillary butterfly (Melitaea cinxia) metapopulation on the [A]land islands, in the Baltic Sea, to fill this gap. We investigated whether bacterial communities associated with larvae show signs of gradual temporal change in response to slow environmental warming across a 28-year period, or whether these communities responded through abrupt change following a sudden drought event that triggered bottlenecks in their butterfly host population. Using a combination of 16S rRNA metabarcoding and metagenomic sequencing, we first showed that M. cinxia harbours a set of stable resident bacteria, including Pseudomonas, Telluria, and Enterobacteriaceae bacteria. But we also characterized a gradual shift in the M. cinxia associated bacterial community over three decades of increasing temperatures and decreasing precipitations. This shift was not unidirectional for all bacterial taxa, as the dominant Telluria and Pseudomonas showed opposing responses to environmental trends. Additionally, the 2018 extreme drought, which triggered acute host population bottlenecks, was associated with a severe disruption of M. cinxia microbiota, and the loss of key Enterobacteriaceae taxa. However, the M. cinxia bacterial community seemed to be able to recover towards pre-drought structure in subsequent years, suggesting a degree of resilience to acute climatic perturbations in this microbial system.

microbiology↗

Progress in the molecular Phylogeny of Cotesia acuminata and C. melitaearum cryptic species complexes

Cryptic species present major challenges for biodiversity and evolutionary research due to the morphological similarity and frequent lack of genetic and ecological data. In parasitoids wasps, this is especially true for lineages with limited sampling and unclear species boundaries. Here we reconstruct the phylogeny of Cotesia wasps parasitizing Melitaeini butterflies, including two cryptic species complexes (Cotesia acuminata agg. and C. melitaearum agg.). Using a ten-gene dataset from samples collected in Europe, Asia, and North America, we inferred relationships among 22 Cotesia species using maximum likelihood. We also included non-Melitaeini associated Cotesia to assess whether the Melitaeini parasitoids form a monophyletic group. Our analyses yielded a highly supported phylogeny, revealing four major clades, three of which included the Melitaeini associated species. This confirms that the Cotesia attacking Melitaeini butterflies are polyphyletic, resulting from independent host shifts across the genus. Each clade is further subdivided into subclades corresponding to the different (cryptic) species, clarifying previously unresolved relationships. These results provide a robust framework for future studies on the evolution, ecology, and host use dynamics of Cotesia wasps and highlight the utility of multi-locus data for resolving phylogenies in morphologically cryptic taxa.

evolutionary biology↗

A high-quality draft genome assembly of the Neotropical butterfly, Batesia hypochlora (Nymphalidae: Biblidinae)

We report a long-read high-coverage reference genome assembly of the Neotropical butterfly, Batesia hypochlora (Nymphalidae: Biblidinae). This represents the first reference genome in the Biblidinae subfamily, a clade subject to ongoing studies on seasonal and climate adaptation in the Amazon. We assembled the genome from PacBio HiFi long reads (66X coverage), polished it with Illumina short reads (15X coverage), and annotated it using PacBio IsoSeq RNA data. We observed 15 chromosome-sized scaffolds varying in length from 13.2 Mbp to 37.6 Mbp (median 24.3 Mbp), combining a total genome size of 395.788 Mbp. This assembly is highly contiguous (contig N50 of 25.14 Mbp) and complete (BUSCO completeness score of 98.6% and 0.2% duplication rate). Repeat annotation revealed that the genome consists of about one-third transposable elements. Gene prediction using RNAseq evidence uncovered 19,395 genes, of which 17,400 were assigned to 2,883 orthogroups when including genomes of the fruitfly, silk moth, and three other Nymphalid butterfly species. The high sequencing depth also allowed us to assemble the genomes of the mitochondria and the common endosymbiotic bacterium Wolbachia. The mitochondrial genome was fully assembled (15,540 bp in size) with all expected genes annotated. The Wolbachia genome was fragmented, and we determined that it belongs to the B-supergroup. The high-quality assembly of B. hypochlora can represent the subfamily in further comparative analysis of evolution and provide a key resource for ongoing work to explore reproductive biology and adaptations to seasonality in Amazonian butterflies.

genomics↗

Recovering ecological interactions by mining non-target data from whole genome re-sequencing projects

The study of parasitic species can shed light on aspects of their hosts ecology. Such interactions are however often unknown or understudied due to the difficulty to detect and/or quantify many infections. Whole-genome sequencing and re-sequencing data have been generated at an increasing rate and reduced costs over the last two decades. Projects based on whole organisms, like whole insect specimens, provide genomic material for the target taxon, but may also include sequencing reads from associated microbes and other parasites. Here, we screened for the presence of non-host reads in a collection of whole-genome (re-) sequence projects from the Glanville fritillary butterfly, Melitaea cinxia, a model organism in research on the ecology and evolution of species in spatially structured and fragmented landscapes. We identified infections with different bacteria and eukaryotic parasites, which are shared between populations and underly both previously known and new biotic interactions for this butterfly species. The bacterial symbiont Wolbachia, usually common in insects, was found at relatively low prevalence, while Spiroplasma was ubiquitous across samples from several European populations of the butterfly. Additionally, we confirmed expected rates of larval parasitism by at least two parasitoid wasps. Such results provide proof of principle that key ecological interactions can be uncovered efficiently from existing data, an important first step to characterising the role host-associated organisms play in shaping the ecology and evolutionary history of their host species.

ecology↗

Species-associated bacterial diversity increases along a gradient of habitat degradation

Alterations of microbial communities have evident impacts on development, digestion, fecundity, metabolism, immunity, and diverse other biological functions of their hosts. Yet, the factors affecting microbial communities associated with wild species often remain uncharacterized. For example, the impact of the hosts habitat degradation due to anthropogenic activities has received little attention, which contrasts with the large literature showing how such habitat degradation is at least partly responsible for the on-going global patterns of macro-biodiversity erosion. Here, we use metacommunities of herbivorous insect species specialized in feeding on Plantago lanceolata in the fragmented landscape of the [A]land Islands, Finland, as a model system to test whether and how bacterial communities associated with wild species change along a gradient of habitat degradation. We evaluated microbial species diversity and community composition in two sympatric insect species sampled from local meadow habitats with various levels of human disturbance within or around these habitats (e.g. forests, roads, agriculture fields, buildings). Counter to our expectations, we found that bacterial diversity can increase with habitat degradation, with individuals from more degraded habitats hosting more rare bacterial species. In contrast, as the dominant microbial species remain similar across habitats, the community composition and function of the microbiota persist under habitat degradation. In this system, the strength of human activities might induce changes in habitat heterogeneity rather than changes in overall habitat quality, thus allowing local insects to encounter and host more rare microbes rather than trigger local microbial extinction.

microbiology↗

Positive fitness effects help explain the broad range of Wolbachia prevalences in natural populations

The bacterial endosymbiont Wolbachia is best known for its ability to modify its hosts reproduction by inducing cytoplasmic incompatibility (CI) to facilitate its own spread. Classical models predict either near-fixation of costly Wolbachia once the symbiont has overcome a threshold frequency (invasion barrier), or Wolbachia extinction if the barrier is not overcome. However, natural populations do not all follow this pattern: Wolbachia can also be found at low frequencies (below one half) that appear stable over time. Wolbachia is known to have pleiotropic fitness effects (beyond CI) on its hosts. Existing models typically focus on the possibility that these are negative. Here we consider the possibility that the symbiont provides direct benefits to infected females (e.g. resistance to pathogens) in addition to CI. We discuss an underappreciated feature of Wolbachia dynamics: that CI with additional fitness benefits can produce low-frequency (< 1/2) stable equilibria. Additionally, without a direct positive fitness effect, any stable equilibrium close to one half will be sensitive to perturbations, which make such equilibria unlikely to sustain in nature. The results hold for both diplodiploid and different haplodiploid versions of CI. We suggest that insect populations showing low-frequency Wolbachia infection might host CI-inducing symbiotic strains providing additional (hidden or known) benefits to their hosts, especially when classical explanations (ongoing invasion, source-sink dynamics) have been ruled out.

ecology↗

Exploring bycatch diversity of organisms in whole genome sequencing of Erebidae moths (Lepidoptera)

Models estimate that up to 80% of all butterfly and moth species host vertically transmitted endosymbiotic microorganisms, which can affect the host fitness, metabolism, reproduction, population dynamics, and genetic diversity, among others. The supporting empirical data are however currently highly biased towards the generally more colourful butterflies, and include less information about moths. Additionally, studies of symbiotic partners of Lepidoptera predominantly focus on the common bacterium Wolbachia pipientis, while infections by other inherited microbial partners have more rarely been investigated. Here, we mine the whole genome sequence data of 47 species of Erebidae moths, with the aims to both inform on the diversity of symbionts potentially associated with this Lepidoptera group, and discuss the potential of metagenomic approaches to inform on their associated microbiome diversity. Based on the result of Kraken2 and MetaPhlAn2 analyses, we found clear evidence of the presence of Wolbachia in four species. Our result also suggests the presence of three other bacterial symbionts (Burkholderia spp., Sodalis spp. and Arsenophonus spp.), in three other moth species. Additionally, we recovered genomic material from bracovirus in about half of our samples. The detection of the latter, usually found in mutualistic association to braconid parasitoid wasps, may inform on host-parasite interactions that take place in the natural habitat of the Erebidae moths, suggesting either contamination with material from species of the host community network, or horizontal transfer of members of the microbiome between interacting species.

genomics↗

Improved chromosome level genome assembly of the Glanville fritillary butterfly (Melitaea cinxia) based on SMRT Sequencing and linkage map.

The Glanville fritillary (Melitaea cinxia) butterfly is a long-term model system for metapopulation dynamics research in fragmented landscapes. Here, we provide a chromosome level assembly of the butterflys genome produced from Pacific Biosciences sequencing of a pool of males, combined with a linkage map from population crosses. The final assembly size of 484 Mb is an increase of 94 Mb on the previously published genome. Estimation of the completeness of the genome with BUSCO, indicates that the genome contains 93 - 95% of the BUSCO genes in complete and single copies. We predicted 14,830 gene models using the MAKER pipeline and manually curated 1,232 of these gene models. The genome and its annotated gene models are a valuable resource for future comparative genomics, molecular biology, transcriptome and genetics studies on this species.

genomics↗