Transfer Events Research Articles

Directly Imaging and Regulating the Nanoscale Inhomogeneity of S-Vacancies in Molybdenum Disulfide Monolayer during Electrocatalytic Hydrogen Evolution.

The study of electron transfer event on two-dimensional (2D) layered transition metal dichalcogenides has attracted tremendous attentions attributing to their promising applications in electrochemical devices. Herein, we demonstrate an opto-electrochemical strategy to directly map and regulate electron transfer event on molybdenum disulfide (MoS2 ) monolayer by combining bright field (BF) imaging technique with electrochemical modulation. The heterogeneity of electrochemical activity on MoS2 monolayer down to nanoscale is resolved spatiotemporally. The thermodynamics of MoS2 monolayer is measured during electrocatalytic hydrogen evolution, and the Arrhenius correlations are obtained. We validate that the defect generation engineered by oxygen plasma bombardment dramatically enhances the local electrochemical activity of MoS2 monolayer, which can be attributed to point defects of S-vacancies as evidenced. Furthermore, by comparing the difference of electron transfer event on MoS2 with various layers, the interlayer coupling effect is uncovered. This study represents a facile method to image the heterogeneity of electrochemical properties for nanomaterials with atomic thickness and regulate the local activity within the plane by extrinsic factors. It also has potential applications in the design and evaluation of high-performance layered electrochemical systems down to nanoscale.

Electrode/Electrolyte Synergy for Concerted Promotion of Electron and Proton Transfers toward Efficient Neutral Water Oxidation

AbstractNeutral water oxidation is a crucial half‐reaction for various electrochemical applications requiring pH‐benign conditions. However, its sluggish kinetics with limited proton and electron transfer rates greatly impacts the overall energy efficiency. In this work, we created an electrode/electrolyte synergy strategy for simultaneously enhancing the proton and electron transfers at the interface toward highly efficient neutral water oxidation. The charge transfer was accelerated between the iridium oxide and in situ formed nickel oxyhydroxide on the electrode end. The proton transfer was expedited by the compact borate environment that originated from hierarchical fluoride/borate anions on the electrolyte end. These concerted promotions facilitated the proton‐coupled electron transfer (PCET) events. Due to the electrode/electrolyte synergy, Ir−O and Ir−OO− intermediates could be directly detected by in situ Raman spectroscopy, and the rate‐limiting step of Ir−O oxidation was determined. This synergy strategy can extend the scope of optimizing electrocatalytic activities toward more electrode/electrolyte combinations.

Molecular characterization of a novel fungal alphaflexivirus reveals potential inter-species horizontal gene transfer

Sclerotinia sclerotiorum is a notorious phytopathogenic fungus that harbors diverse mycoviruses. A novel positive-sense single-stranded RNA virus, Sclerotinia sclerotiorum alphaflexivirus 2 (SsAFV2), was isolated from the hypovirulent strain 32–9 of S. sclerotiorum, and its complete genome was determined. The SsAFV2 genome contains 7,162 nucleotides (nt), excluding the poly (A) structure, and is composed of four open reading frames (ORF1–4). ORF1 encodes a polyprotein that contains three conserved domains: methyltransferase, helicase, and RNA-dependent RNA polymerase (RdRp). The ORF3 putative encodes coat proteins (CP), with ORF2 and ORF4 encoding hypothetical proteins of unknown functions. Phylogenetic analysis revealed that SsAFV2 clustered with Botrytis virus X (BVX) based on multiple alignments of helicase, RdRp, and CP, but the methyltransferase of SsAFV2 was most closely related to Sclerotinia sclerotiorum alphaflexivirus 1, suggesting that SsAFV2 is a new member of the Botrexvirus genus within the Alphaflexiviridae family, and also revealed the occurrence of potential inter-species horizontal gene transfer events within the Botrexvirus genus during the evolutionary process. Our results contribute to the current knowledge regarding the evolution and divergence of Botrexviruses.

Host shift promotes divergent evolution between closely related holoparasitic species

Distinct hosts have been hypothesized to possess the potential for affecting species differentiation and genome evolution of parasitic organisms. However, what host shift history is experienced by the closely related parasites and whether disparate evolution of their genomes occur remain largely unknown. Here, we screened horizontal gene transfer (HGT) events in a pair of sister species of holoparasitic Boschniakia (Orobanchaceae) having obligate hosts from distinct families to recall the former host-parasite associations and performed a comparative analysis to investigate the difference of their organelle genomes. Except those from the current hosts (Ericaceae and Betulaceae), we identified a number of HGTs from Rosaceae supporting the occurrence of unexpected ancient host shifts. Different hosts transfer functional genes which changed nuclear genomes of this sister species. Likewise, different donors transferred sequences to their mitogenomes, which vary in size due to foreign and repetitive elements rather than other factors found in other parasites. The plastomes are both severely reduced, and the degree of difference in reduction syndrome reaches the intergeneric level. Our findings provide new insights into the genome evolution of parasites adapting to different hosts and extend the mechanism of host shift promoting species differentiation to parasitic plant lineages.

The Sapria himalayana genome provides new insights into the lifestyle of endoparasitic plants

BackgroundSapria himalayana (Rafflesiaceae) is an endoparasitic plant characterized by a greatly reduced vegetative body and giant flowers; however, the mechanisms underlying its special lifestyle and greatly altered plant form remain unknown. To illustrate the evolution and adaptation of S. himalayasna, we report its de novo assembled genome and key insights into the molecular basis of its floral development, flowering time, fatty acid biosynthesis, and defense responses.ResultsThe genome of S. himalayana is ~ 1.92 Gb with 13,670 protein-coding genes, indicating remarkable gene loss (~ 54%), especially genes involved in photosynthesis, plant body, nutrients, and defense response. Genes specifying floral organ identity and controlling organ size were identified in S. himalayana and Rafflesia cantleyi, and showed analogous spatiotemporal expression patterns in both plant species. Although the plastid genome had been lost, plastids likely biosynthesize essential fatty acids and amino acids (aromatic amino acids and lysine). A set of credible and functional horizontal gene transfer (HGT) events (involving genes and mRNAs) were identified in the nuclear and mitochondrial genomes of S. himalayana, most of which were under purifying selection. Convergent HGTs in Cuscuta, Orobanchaceae, and S. himalayana were mainly expressed at the parasite–host interface. Together, these results suggest that HGTs act as a bridge between the parasite and host, assisting the parasite in acquiring nutrients from the host.ConclusionsOur results provide new insights into the flower development process and endoparasitic lifestyle of Rafflesiaceae plants. The amount of gene loss in S. himalayana is consistent with the degree of reduction in its body plan. HGT events are common among endoparasites and play an important role in their lifestyle adaptation.

Ribosome inactivating proteins in insects: HGT, gene expression, and functional implications

Ribosome-inactivating proteins (RIPs) are RNA N-glycosidases that depurinate an adenine residue in the conserved alpha-sarcin/ricin loop (SRL) of rRNA, inhibiting protein synthesis. Previously, we reported the existence of these toxins in insects, whose presence is restricted to mosquitoes from the Culicinae subfamily (e.g., Aedes aegypti) and whiteflies from the Aleyrodidae family (e.g., Bemisia tabaci). Both groups of genes are derived from two independent horizontal gene transfer (HGT) events and are evolving under purifying selection. Here, we report and characterize the occurrence of a third HGT event in the Sciaroidea superfamily, which supports the recurrent acquisition of RIP genes by insects. Transcriptomic experiments, available in databases, allowed us to describe the temporal and spatial expression profiles for these foreign genes in these organisms. Furthermore, we found that RIP expression is induced after infection with pathogens and provided, for the first time, transcriptomic evidence of parasite SRL depurination. This evidence suggests a possible role of these foreign genes as immune effectors in insects.

The transfer of fibres between garments in a choreographed assault scenario

Our fundamental understanding of fibre transfer remains based on early seminal transfer studies that were largely mechanical simulations. However, transfer events in the real world are uncontrolled in nature. This study takes a novel approach to address this discrepancy, with skilled jiu-jitsu practitioners performing a choreographed ‘standard’ assault scenario to investigate the transfer of fibres between a cotton T-shirt and cotton/polyester hoody. Garments were collected immediately after the scenario and examined for the number, length and zonal distribution of transferred fibres. It was observed that cotton transferred the most fibres, on average twice as many from blended hoodies than T-shirts; whilst polyester transferred the least. Shorter fibres transferred and were recovered more readily than longer fibres; however, it was more likely to recover polyester fibres> 5 mm. The number and length of fibres transferred from the attacker’s garment mainly depended on the construction of the donor textile (including sheddability) and properties of the fibres. Conversely, properties of the recipient textile were more significant factors when considering transfer from the victim’s garment. Location of recovered fibres was found to be dependent on the wearer’s role, but generally, upper zones and sleeves of both garments were most populated. Overall, these results will contribute to grow our current knowledge base regarding fibre transfer between donor and recipient textiles in a common assault situation. This will ultimately aid experts support evaluation with regards to competing hypotheses such as in a Bayesian framework.

Metal Ion-Linked Molecular Multilayers on Inorganic Substrates: Structure and Applications

Metal ion-linked multilayers have emerged as a simple and modular means of assembling molecular components on an inorganic substrate. The choice of molecules, based on their excited state energies and redox potentials, has enabled the directional control of energy and electron transfer events for application in electrochromics, solar energy harvesting, molecular rectifiers, photocatalysis, and more. Here, we recount the more than 35-year journey of metal ion-linked multilayers and their transition from planar to mesoporous substrates and from homogeneous to heterogeneous multilayers. This includes showcasing the vast range of components (i.e., substrates, metal ions, and molecules), structural insights, and applications. We also highlight current limitations in our knowledge of and ability to control these systems which must be overcome to realize the full potential of metal ion-linked multilayers.

Comparative genomics reveals the emergence of copper resistance in a non-pigmented Xanthomonas pathogen of grapevine.

Xanthomonas citri pv. viticola (Xcv) is the causal agent of bacterial canker in grapevine. The pathogen is restricted to India, where it was first reported in the 1970s, and Brazil. In the present study, we report the first complete genome sequence of Xcv LMG965, which is a reference pathotype strain. We also report genome sequences of additional isolates from India and comparative genome-based studies of isolates from Brazil. Apart from revealing the monophyletic origin of the pathovar, we could also confirm a common frameshift mutation in a gene that is part of the Xanthomonadin pigment biosynthetic gene cluster in all the isolates. The comparative study also revealed multiple intrinsic copper resistance-related genes in Brazilian isolates, suggesting intense selection, possibly because of heavy and indiscriminate usage of copper as an antimicrobial agent in the orchards. There is also the association of a Tn3-like transposase in the vicinity of the copper resistance genes, indicating a potential for rapid diversification through horizontal gene transfer events. The findings, along with genomic resources, will allow for systematic genetic and functional studies of Xcv.

Detailed mapping of Bifidobacterium strain transmission from mother to infant via a dual culture-based and metagenomic approach

A significant proportion of the infant gut microbiome is considered to be acquired from the mother during and after birth. Thus begins a lifelong and dynamic relationship with microbes that has an enduring impact on host health. Based on a cohort of 135 mother-infant (F = 72, M = 63) dyads (MicrobeMom: ISRCTN53023014), we investigated the phenomenon of microbial strain transfer, with a particular emphasis on the use of a combined metagenomic-culture-based approach to determine the frequency of strain transfer involving members of the genus Bifidobacterium, including species/strains present at low relative abundance. From the isolation and genome sequencing of over 449 bifidobacterial strains, we validate and augment metagenomics-based evidence to reveal strain transfer in almost 50% of dyads. Factors important in strain transfer include vaginal birth, spontaneous rupture of amniotic membranes, and avoidance of intrapartum antibiotics. Importantly, we reveal that several transfer events are uniquely detected employing either cultivation or metagenomic sequencing, highlighting the requirement for a dual approach to obtain an in-depth insight into this transfer process.

Horizontally Acquired Nitrate Reductase Realized Kleptoplastic Photoautotrophy ofRapaza viridis.

While photoautotrophic organisms utilize inorganic nitrogen as the nitrogen source, heterotrophic organisms utilize organic nitrogen and thus do not generally have an inorganic nitrogen assimilation pathway. Here, we focused on the nitrogen metabolism of Rapaza viridis, a unicellular eukaryote exhibiting kleptoplasty. Although belonging to the lineage of essentially heterotrophic flagellates, R. viridis exploits the photosynthetic products of the kleptoplasts and was therefore suspected to potentially utilize inorganic nitrogen. From the transcriptome data of R. viridis, we identified gene RvNaRL, which had sequence similarity to genes encoding nitrate reductases in plants. Phylogenetic analysis revealed that RvNaRL was acquired by a horizontal gene transfer event. To verify the function of the protein product RvNaRL, we established RNAi-mediated knock-down and CRISPR-Cas9-mediated knock-out experiments for the first time in R. viridis and applied them to this gene. The RvNaRL knock-down and knock-out cells exhibited significant growth only when ammonium was supplied. However, in contrast to the wild-type cells, no substantial growth was observed when nitrate was supplied. Such arrested growth in the absence of ammonium was attributed to impaired amino acid synthesis due to the deficiency of nitrogen supply from the nitrate assimilation pathway; this in turn resulted in the accumulation of excess photosynthetic products in the form of cytosolic polysaccharide grains, as observed. These results indicate that RvNaRL is certainly involved in nitrate assimilation by R. viridis. Thus, we inferred that R. viridis achieved its advanced kleptoplasty for photoautotrophy, owing to the acquisition of nitrate assimilation via horizontal gene transfer.

6-MSA, a secondary metabolite distribution hub with multiple fungal destinations.

6-methylsalicylic acid is a small, simple polyketide produced by a broad spectrum of fungal species. Since fungi obtained the ability to synthesize 6-MSA from bacteria through a horizontal gene transfer event, it has developed into a multipurpose metabolic hub from where numerous complex compounds are produced. The most relevant metabolite from a human perspective is the small lactone patulin as it is one of the most potent mycotoxins. Other important end products derived from 6-MSA include the small quinone epoxide terreic acid and the prenylated yanuthones. The most advanced modification of 6-MSA is observed in the aculin biosynthetic pathway, which is mediated by a non-ribosomal peptide synthase and a terpene cyclase. In this short review, we summarize for the first time all the possible pathways that takes their onset from 6-MSA and provide a synopsis of the responsible gene clusters and derive the resulting biosynthetic pathways.

Imaging the Self-Healing Dynamics of Single-Nanoparticle Electron Transfer Event Regulated by Local Electron Insertion.

The self-healing properties of nanomaterials to resist electron beam damage are of great concern, which is inspiring to improve the stability and electron transfer efficiency of nanoelectronic devices especially in an abnormal environment. However, the influence of electron beam insertion on the electron transfer efficiency of single nanoentities at a heterogeneous electrochemical interface is still in debate, which is a concern for the development of in situ liquid cell transmission electron microscopy of the next generation. Herein, we employ an electro-optical imaging technique and directly visualize the controllable recovery of electron transfer ability for single Prussian blue nanoparticle (PBNP) after electron beam insertion with different electron doses. While eliminating e-beam damage by decreasing charge accumulation, the precise control of electron insertion behaviors induces a lossless chemical reduction mechanism for metal ions on the framework structure of PBNP, which leads to static imbalance and temporarily blocks the electron transfer channels. A subsequent charge rebalance process at a sub-nanoparticle level driven by electrochemical cycling controllably rebuilds the ion migration channels on the outer layer of single PBNP to repair the electron transfer path, which is confirmed by single-nanoparticle spectral characterizations. This work provides a generic methodology to study the electron-particle interplay and mechanism of electrode materials for eliminating the heterogeneity of electrochemical activity down to a sub-nanoparticle level.

Oskar acts with the transcription factor Creb to regulate long-term memory in crickets

Novel genes have the potential to drive the evolution of new biological mechanisms, or to integrate into preexisting regulatory circuits and contribute to the regulation of older, conserved biological functions. One such gene, the novel insect-specific gene oskar, was first identified based on its role in establishing the Drosophila melanogaster germ line. We previously showed that this gene likely arose through an unusual domain transfer event involving bacterial endosymbionts and played a somatic role before evolving its well-known germ line function. Here, we provide empirical support for this hypothesis in the form of evidence for a neural role for oskar. We show that oskar is expressed in the adult neural stem cells of a hemimetabolous insect, the cricket Gryllus bimaculatus. In these stem cells, called neuroblasts, oskar is required together with the ancient animal transcription factor Creb to regulate long-term (but not short-term) olfactory memory. We provide evidence that oskar positively regulates Creb, which plays a conserved role in long-term memory across animals, and that oskar in turn may be a direct target of Creb. Together with previous reports of a role for oskar in nervous system development and function in crickets and flies, our results are consistent with the hypothesis that oskar's original somatic role may have been in the insect nervous system. Moreover, its colocalization and functional cooperation with the conserved pluripotency gene piwi in the nervous system may have facilitated oskar's later co-option to the germ line in holometabolous insects.

Mechanistic roles of metal- and ligand-protonated species in hydrogen evolution with [Cp*Rh] complexes

Protonation reactions involving organometallic complexes are ubiquitous in redox chemistry and often result in the generation of reactive metal hydrides. However, some organometallic species supported by η5-pentamethylcyclopentadienyl (Cp*) ligands have recently been shown to undergo ligand-centered protonation by direct proton transfer from acids or tautomerization of metal hydrides, resulting in the generation of complexes bearing the uncommon η4-pentamethylcyclopentadiene (Cp*H) ligand. Here, time-resolved pulse radiolysis (PR) and stopped-flow spectroscopic studies have been applied to examine the kinetics and atomistic details involved in the elementary electron- and proton-transfer steps leading to complexes ligated by Cp*H, using Cp*Rh(bpy) as a molecular model (where bpy is 2,2'-bipyridyl). Stopped-flow measurements coupled with infrared and UV-visible detection reveal that the sole product of initial protonation of Cp*Rh(bpy) is [Cp*Rh(H)(bpy)]+, an elusive hydride complex that has been spectroscopically and kinetically characterized here. Tautomerization of the hydride leads to the clean formation of [(Cp*H)Rh(bpy)]+. Variable-temperature and isotopic labeling experiments further confirm this assignment, providing experimental activation parameters and mechanistic insight into metal-mediated hydride-to-proton tautomerism. Spectroscopic monitoring of the second proton transfer event reveals that both the hydride and related Cp*H complex can be involved in further reactivity, showing that [(Cp*H)Rh] is not necessarily an off-cycle intermediate, but, instead, depending on the strength of the acid used to drive catalysis, an active participant in hydrogen evolution. Identification of the mechanistic roles of the protonated intermediates in the catalysis studied here could inform design of optimized catalytic systems supported by noninnocent cyclopentadienyl-type ligands.

Mechanistic Insight into Anion‐Binding Catalytic Living Cationic Polymerization

AbstractExploiting non‐covalent interactions to catalyze challenging ionic polymerizations is an ambitious goal but is in its infancy. We recently demonstrated non‐covalent anion‐binding catalysis as an effective methodology to enable living cationic polymerization (LCP) of vinyl ethers in an environmentally benign manner. Here, we further elucidate the structure‐reactivity relationships of the elaborately designed seleno‐cyclodiphosph(V)azanes catalysts and the roles of anion‐binding interactions by a combined theoretical DFT study and experimental study. The investigation suggests that the distinct cis‐cyclodiphosph(V)azane framework combined with “selenium effect” and electron‐withdrawing 3,5‐(CF3)2‐Phenyl substitution pattern in catalyst enables a critical contribution to accessing excellent stability, anion affinity and solubility under polymerization conditions. Thus, the catalyst could leverage anion‐binding interactions to precisely control reversible and transient dormant‐active species equilibrium, allowing it to dynamically bind, recognize and pre‐organize propagating ionic species and monomer, thereby facilitating efficient chain propagation and minimizing irreversible chain transfer events under mild conditions. The more in‐depth understanding of the mechanism for anion‐binding catalytic LCP reported herein should help to guide future catalyst design and to extend this concept to broader polymerization systems where ionic species serve as crucial intermediates.

Mechanistic Insight into Anion-Binding Catalytic Living Cationic Polymerization.

Exploiting non-covalent interactions to catalyze challenging ionic polymerizations is an ambitious goal but is in its infancy. We recently demonstrated non-covalent anion-binding catalysis as an effective methodology to enable living cationic polymerization (LCP) of vinyl ethers in an environmentally benign manner. Here, we further elucidate the structure-reactivity relationships of the elaborately designed seleno-cyclodiphosph(V)azanes catalysts and the roles of anion-binding interactions by a combined theoretical DFT study and experimental study. The investigation suggests that the distinct cis-cyclodiphosph(V)azane framework combined with "selenium effect" and electron-withdrawing 3,5-(CF3 )2 -Phenyl substitution pattern in catalyst enables a critical contribution to accessing excellent stability, anion affinity and solubility under polymerization conditions. Thus, the catalyst could leverage anion-binding interactions to precisely control reversible and transient dormant-active species equilibrium, allowing it to dynamically bind, recognize and pre-organize propagating ionic species and monomer, thereby facilitating efficient chain propagation and minimizing irreversible chain transfer events under mild conditions. The more in-depth understanding of the mechanism for anion-binding catalytic LCP reported herein should help to guide future catalyst design and to extend this concept to broader polymerization systems where ionic species serve as crucial intermediates.

Endemicity and diversification of carbapenem-resistant Acinetobacter baumannii in an intensive care unit

Carbapenem-resistant Acinetobacter baumannii (CRAB) is a major public health concern globally. Often studied in the context of hospital outbreaks, little is known about the persistence and evolutionary dynamics of endemic CRAB populations. A three-month cross-sectional observational study was conducted in a 28-bed intensive care unit (ICU) in Hangzhou, China. A total of 5068 samples were collected from the hospital environment (n=3985), patients (n=964) and staff (n=119). CRAB isolates were obtained from 10.5% of these samples (n=532). All of these isolates, plus an additional 19 from clinical infections, were characterised through whole-genome sequencing. The ICU CRAB population was dominated by OXA-23-producing global clone 2 isolates (99.3% of all isolates) that could be divided into 20 distinct clusters, defined through genome sequencing. CRAB was persistently present in the ICU, driven by regular introductions of distinct clusters. The hospital environment was heavily contaminated, with CRAB isolated from bed units on 183/335 (54.6%) sampling occasions but from patients on only 72/299 (24.1%) occasions. CRAB was spread to adjacent bed units and rooms, and following re-location of patients within the ICU. We also observed three horizontal gene transfer events between CRAB strains in the ICU, involving three different plasmids. The epidemiology of CRAB in this setting contrasted with previously described clonal outbreaks in high-income countries, highlighting the importance of environmental CRAB reservoirs in ICU epidemiology and the unique challenges in containing the spread of CRAB in ICUs where this important multidrug-resistant pathogen is endemic. This work was undertaken as part of the DETECTIVE research project funded by the Medical Research Council (MR/S013660/1), National Natural Science Foundation of China (81861138054, 32011530116, 31970128, 31770142), Zhejiang Province Medical Platform Backbone Talent Plan (2020RC075), and the National Key Research and Development Program of China grant (2018YFE0102100). W.v.S was also supported by a Wolfson Research Merit Award (WM160092).

A novel aminotransferase gene and its regulator acquired in Saccharomyces by a horizontal gene transfer event

BackgroundHorizontal gene transfer (HGT) is an evolutionary mechanism of adaptive importance, which has been deeply studied in wine S. cerevisiae strains, where those acquired genes conferred improved traits related to both transport and metabolism of the nutrients present in the grape must. However, little is known about HGT events that occurred in wild Saccharomyces yeasts and how they determine their phenotypes.ResultsThrough a comparative genomic approach among Saccharomyces species, we detected a subtelomeric segment present in the S. uvarum, S. kudriavzevii, and S. eubayanus species, belonging to the first species to diverge in the Saccharomyces genus, but absent in the other Saccharomyces species. The segment contains three genes, two of which were characterized, named DGD1 and DGD2. DGD1 encodes dialkylglicine decarboxylase, whose specific substrate is the non-proteinogenic amino acid 2-aminoisobutyric acid (AIB), a rare amino acid present in some antimicrobial peptides of fungal origin. DGD2 encodes putative zinc finger transcription factor, which is essential to induce the AIB-dependent expression of DGD1. Phylogenetic analysis showed that DGD1 and DGD2 are closely related to two adjacent genes present in Zygosaccharomyces.ConclusionsThe presented results show evidence of an early HGT event conferring new traits to the ancestor of the Saccharomyces genus that could be lost in the evolutionary more recent Saccharomyces species, perhaps due to loss of function during the colonization of new habitats.

Multiple lineages of nematode-Wolbachia symbiosis in supergroup F and convergent loss of bacterioferritin in filarial Wolbachia.

The intracellular endosymbiotic proteobacteria Wolbachia have evolved across the phyla nematoda and arthropoda. In Wolbachia phylogeny, supergroup F is the only clade known so far with members from both arthropod and filarial nematode hosts and therefore can provide unique insights into their evolution and biology. In this study, 4 new supergroup F Wolbachia genomes have been assembled using a metagenomic assembly and binning approach, wMoz and wMpe from the human filarial parasites Mansonella ozzardi and Mansonella perstans, and wOcae and wMoviF from the blue mason bee Osmia caerulescens and the sheep ked Melophagus ovinus respectively. A comprehensive phylogenomic analysis revealed two distinct lineages of filarial Wolbachia in supergroup F, indicating multiple horizontal transfer events between arthropod and nematode hosts. The analysis also reveals that the evolution of Wolbachia-filaria symbioses is accompanied by a convergent pseudogenization and loss of the bacterioferritin gene, a phenomenon found to be shared by all filarial Wolbachia, even those outside supergroup F. These observations indicate that differences in heme metabolism might be a key feature distinguishing filarial and arthropod Wolbachia. The new genomes provide a valuable resource for further studies on symbiosis, evolution, and the discovery of new antibiotics to treat mansonellosis.