Biology subjects

Vogel, A.

Publications and source records attributed to Vogel, A..

At least 19 recordsLinked to original sources

bioRxiv2026

Nanophotonic DyeCycling delivers single-molecule FRET beyond photobleaching to identify heterogenous dynamics in DNA and protein systems

With its unique spatiotemporal resolution at the single-molecule level, Forster resonance energy transfer (FRET) is a powerful tool for investigating biomolecular conformational dynamics and function. However, early photobleaching remains a key limitation restricting the achievable observation time and therefore the information gain and application range of single-molecule FRET. Here, we establish nanophotonic DyeCycling, which overcomes photobleaching by reversible fluorophore binding and efficient background suppression using zero-mode waveguides. Nanoscale conformational changes are sensitively resolved from milliseconds up to the hour range, enabling robust kinetic analyses at the single-molecule level. As a result, outlier molecules reflecting static heterogeneity and time-dependent kinetics within individual molecules reflecting dynamic heterogeneity are reliably resolved. The versatility of DyeCycling is demonstrated using DNA and protein systems. Altogether, nanophotonic DyeCycling extends smFRET observations beyond the conventional photobleaching limit, revealing previously inaccessible kinetic effects and providing deeper insight into biomolecular systems with multiple states and rates.

biophysics↗

bioRxiv2026

A cell death screen identifies macrophage-depleting agents with therapeutic potential

Macrophages are critical regulators of inflammation and tissue homeostasis, yet aberrant macrophage activation contributes to a wide spectrum of inflammatory and malignant diseases. Therapeutic strategies that directly reduce macrophage numbers have shown promise, but macrophage survival pathways remain incompletely defined, limiting the development of targeted therapeutic strategies. Here, we establish a high-throughput screening platform to identify small molecule inhibitors that impair macrophage survival. Screening a library of more than 2,000 targeted compounds in a cell survival assay, combined with in silico and in vitro analysis of macrophage specificity, revealed the identification of three potent inhibitors: BIX-01294, GSK-J4, and Masitinib. All three compounds downregulated leukemia inhibitory factor receptor (LIFR), whose inhibition markedly reduced macrophage viability. In vivo, these inhibitors effectively depleted large peritoneal macrophages, ameliorated key symptoms of macrophage activation syndrome (MAS), and suppressed tumor growth in a syngeneic transplanted melanoma model as well as in an autochthonous lung cancer model. Together, these findings identify small molecule-mediated macrophage depletion as a promising therapeutic strategy and establish an experimental approach to uncover regulators of macrophage survival.

immunology↗

bioRxiv2025

Consensus molecular subtypes define distinct evolutionary trajectories of biliary tract cancers

Introduction Biliary tract cancer (BTC) comprises a family of rare malignancies subclassified by anatomy and pathology. However, this scheme may obscure shared biology and limit patient stratification. Objectives We tested whether BTC heterogeneity can be explained by coherent latent axes and evaluated the potential to unify diverse clinical and genomic factors under a tractable biological framework Methods We performed whole-genome and transcriptome sequencing of 180 tumors enriched for tumor cells by laser capture microdissection to identify shared programs in BTC. Results Network integration across transcriptomic classes identified two consensus cancer subtypes (CCS). CCS segregated with anatomical location of primary tumor and gene expression marker analyses suggest subtypes reflect tumor cell of origin differences. CCS displayed strikingly divergent molecular landscapes, explaining more variance than anatomical location of primary tumor. CCS-B tumors were mutationally loaded with clock-like and APOBEC signatures and extrachromosomal DNA, whereas CCS-A tumors were characterized by chromosome-arm deletions. Conclusion Our approach showed that harnessing the genomic and transcriptomic diversity of BTC uncovers novel biology and improves stratification.

cancer biology↗

bioRxiv2025

mRNA-based tuberculosis vaccines BNT164a1 and BNT164b1 are immunogenic, well-tolerated and efficacious in rodent models

We designed and preclinically tested two mRNA-LNP-based vaccine candidates to protect against tuberculosis (TB). BNT164a1 and BNT164b1 encode the same eight Mycobacterium tuberculosis (Mtb) antigens expressed across different infection stages: Ag85A, Hrp1, ESAT-6, RpfD, RpfA, HbhA, M72, and VapB47. BNT164a1 utilizes nucleoside-unmodified mRNA, while BNT164b1 utilizes N1-methyl pseudouridine-modified mRNA. Prime-boost immunization with BNT164 candidates elicited antibody and/or T-cell responses against all antigens in three mouse strains (C57BL/6, BALB/c, and HLA-A2.1/DR1 humanized mice). The candidates demonstrated favorable safety profiles in a rat toxicity study and significantly reduced bacterial burdens of two Mtb strains in murine aerosol challenge models. BNT164 protection correlated with granuloma infiltration by CD8+ T cells with memory precursor phenotypes. In conclusion, BNT164a1 and BNT164b1 were immunogenic, well tolerated and efficacious in preclinical models and are the first mRNA-based TB vaccines to enter phase I/II clinical trials (NCT05537038, NCT05547464).

immunology↗

bioRxiv2025

Pro- and anti-inflammatory macrophages adjust UCP2 protein levels based on their intrinsic metabolism and available metabolites

The immune and metabolic responses of macrophages are closely linked, and mitochondria play a key role in polarizing them into pro-inflammatory (classical) and anti-inflammatory (alternative) states. Mitochondrial uncoupling protein 2 (UCP2) is involved in regulating macrophage inflammation and glucose metabolism; however, its regulatory mechanisms are unclear. We found that inflammatory stimuli reduce UCP2 expression and oxygen consumption rates (OCR), indicating mitochondrial suppression. Conversely, IL-4-activated macrophages displayed higher UCP2 levels and enhanced respiration. Under glucose deprivation, LPS-stimulated macrophages retained mitochondrial activity despite lower UCP2 levels. Pyruvate emerged as a key regulator of UCP2, blocking its mitochondrial entry reduced UCP2 expression. Additionally, hypoxia markedly decreased UCP2 levels in IL-4-activated macrophages, suggesting that hypoxia contributes to UCP2 suppression in pro-inflammatory macrophages. Notably, pro-inflammatory macrophages exhibit reduced reliance on UCP2 due to suppressed mitochondrial respiration. Pyruvate regulates UCP2 expression, highlighting the connection between glycolysis and mitochondrial metabolism. These findings may inform therapeutic strategies for diseases involving immune dysregulation.

biophysics↗

bioRxiv2025

An estrogen-independent and IL-1-dependent pathway controls vulvovaginal candidiasis through combined IL-17/IL-22 signaling

Vulvovaginal candidiasis (VVC) affects >75% of women, with considerable morbidity and high medical cost burden. While Type 17 cytokines (IL-17, IL-22) are critical for oral and dermal immunity to C. albicans, their role in VVC has been less clear. Th17 gene signatures are potently upregulated in VVC, yet impairment of individual Th17 components (IL-17A, IL-17R subunits, IL-22) does not worsen disease. Rather, estrogen activity is tightly linked to VVC, leading to a paradigm that hormonal pathways rather than immune defense, dominate susceptibility. Here, we reveal a previously unappreciated role for IL-1/Type 17 in VVC that operates independently of estrogenic hormones. In contrast to mice lacking IL-17A, IL-17RA, IL-22, or IL-22R individually, mice lacking IL-17RA and IL-22RA1 together (Il17raIl22ra1-/-) exhibited high fungal loads and exacerbated tissue damage and inflammation. In human vulvar epithelial cells, IL-17 and IL-22 drive synergistic signaling. IL-1R signaling but surprisingly not IL-23 wa upstream of this response. Il17raIl22ra1-/- mice expressed high IL-1{beta} yet did not control disease, indicating that IL-1 is upstream but not downstream of Type 17 responses. Unexpectedly, Type 17-dependent control occurred in the absence of exogenous estrogen administration and persisted even when estrus was prevented by progesterone treatment. Collectively, these data indicate that susceptibility to VVC is driven not only by estrogen sensitization but through combinatorial loss of IL-17 and IL-22. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=168 SRC="FIGDIR/small/671995v2_ufig1.gif" ALT="Figure 1000"> View larger version (52K): org.highwire.dtl.DTLVardef@19946e9org.highwire.dtl.DTLVardef@1feac71org.highwire.dtl.DTLVardef@eb433aorg.highwire.dtl.DTLVardef@18ab622_HPS_FORMAT_FIGEXP M_FIG C_FIG

immunology↗

bioRxiv2025

Structural basis of insulin receptor antagonism by bivalent site 1-site 2 ligands

Congenital hyperinsulinism (HI) is a rare genetic disease characterized by overproduction of insulin. One class of potential HI treatments is insulin receptor (IR) antagonists like S961 and Ins-AC-S2, peptides composed of binding segments for each of the IR sites capable of binding insulin: site 1 and site 2. Notably, S597 - containing the same IR binding segments as S961 but in the opposite order (site 2-site 1) - is an IR agonist rather than an antagonist. Using cryo-EM, we show how both S961 and Ins-AC-S2 bind an inactive conformation of IR, thereby explaining their antagonism. Furthermore, our structures reveal how agonist vs. antagonist activity is dictated by the order of site 1- and site 2-binding modules in bivalent ligands. Additionally, we uncover subtle differences between the binding mechanisms of S961 and Ins-AC-S2 to IR, which include displacement or engagement of CT, respectively, and a novel binding interface between the Ins-AC-S2 insulin and the receptor. These structural insights may inform development of next generation IR antagonists for treatment of HI.

molecular biology↗

bioRxiv2025

Real-time Color Flow Mapping of Ultrasound Microrobots

Visualization and tracking of microrobots in real-time pose key challenges for surgical microrobotic systems, as existing imaging modalities like MRI, CT, and X-ray are unable to monitor microscale items with real-time resolution. Ultrasound imaging-guided drug administration represents a significant advancement in this respect, offering real-time visual feedback on invasive medical procedures. However, ultrasound imaging still faces substantial inherent limitations in spatial resolution and signal attenuation, which hinder extending this method to microrobot visualization. Here, we introduce an approach for visualizing individual microrobots in real-time with Color Flow Mapping ultrasound imaging, based on acoustically induced structural oscillations of the microrobot generating a pseudo-Doppler signal. This approach enables the simultaneous localization and activation of bubble-based microrobots using two ultrasound sources operating at distinct frequency bandwidths. Our successful capture of microrobots measuring 60-80 micrometers in diameter reveals the potential of real-time ultrasonic imaging at the microscale. One-sentence SummaryAdvancing ultrasound imaging for real-time, microscale visualization--a critical breakthrough for therapeutic microrobots.

bioengineering↗

bioRxiv2024

Computational metabolic modeling unveils gut microbiomes role in metabolic shifts during murine cancer cachexia

Cancer cachexia is a multifactorial syndrome characterized by involuntary weight loss, muscle wasting, systemic inflammation, and metabolic alterations, affecting up to 87% of pancreatic and gastric cancer patients. Unlike simple starvation, cachexia is driven by metabolic disruption involving both host physiology and the gut microbiome. While microbiome changes in cachexia have been documented, a coherent understanding of how these changes translate into functional metabolic shifts remains elusive. In this study, we combined in vivo fecal and plasma metabolomic analyses with a novel computational microbiome simulation pipeline to identify cachexia-associated microbial metabolites. Using the murine MCA207 tumor line and its cachectic derivative CHX207, we differentiated microbiome changes driven by cachexia from those induced by tumor growth. Our computational tool, McMurGut, a murine-tailored extension of MICOM, enabled simulation of microbial metabolic interactions specific to the mouse microbiome, covering 91% of identified genera. We identified significant abundance changes in 35 microbial genera and corresponding shifts in metabolite production, including reductions in short-chain fatty acids (SCFAs) like acetate and butyrate, alongside increased production of galactose, formate, and propionate. Notably, decreases in SCFA production, particularly by genera such as Faecalibaculum and Dubosiella, correlated with exacerbated cachectic symptoms. Additionally, the elevated production of formate and galactose, primarily by Bacteroides and Lactobacillus, suggested altered fermentation pathways in cachexia, potentially linked to increased mucus degradation. Validation of our computational predictions via NMR metabolomics highlighted key congruencies between predicted and experimentally observed metabolites, supporting the role of microbiome-driven metabolic shifts in cachexia pathology. These findings provide crucial insights into the microbiomes involvement in cachexia and suggest future avenues for therapeutic interventions aimed at modulating microbial taxa and their metabolic outputs to improve patient outcomes.

microbiology↗

bioRxiv2023

Effects of recurrent summer droughts on arbuscular mycorrhizal and total fungal communities in experimental grasslands differing in plant diversity and community composition

Biodiversity loss and climate change have been determined as major global drivers affecting ecosystems and their functioning. In this context, drought was shown to have negative effects on ecosystems by disrupting ecological processes, which could be buffered in more biodiverse systems. Many studies, however, focus on effects on aboveground communities of single drought events, while dynamics of soil-borne communities are still widely unclear, despite their important roles in ecosystem functioning. To elucidate the effect of recurrent summer drought periods on fungal communities in a long-term grassland biodiversity experiment, roof shelters were installed on grassland plots ranging in plant species richness from 1 to 16 species and plant functional group richness (1-4 groups) and composition. After 9 years of summer droughts, bulk soil was sampled and used for Illumina sequencing of the ITS2 and SSU genes to characterize the total fungal and arbuscular mycorrhizal fungal (AMF) communities, respectively. We found shifts of AMF and total fungi community structures caused by recurrent drought and plant species richness, but no buffering of drought effects by plant diversity. Alpha-diversity (VT or ASV richness) of both AMF and total fungi increased with plant species richness but was not significantly affected by drought. Even though drought overall had minimal long-lasting effects, we found Diversispora and Paraglomus among the AMF and Penicillium among total fungal communities to be more abundant after the drought treatment. AMF communities were affected by the presence of individual plant functional groups, reacting stronger to presence of legumes under drought, while total fungal interaction with plant communities were similar under drought as control. AMF -diversity differed between plant functional groups in control conditions but was independent of plant community composition under drought. In contrast, total fungi -diversity was increased by presence of herbs and legumes only under drought. From our results, we conclude that recurring moderate summer droughts do not strongly affect soil fungal communities. All shifts can be explained by indirect effects through the plant community and its top-down effect on soils altered by drought. Further, AMF are not less affected than total fungal communities, but rather respond differently by interacting more strongly with legumes in response to drought. Consequently, not plant species richness, but plant functional composition, dominates in shaping fungal communities under recurrent droughts.

ecology↗

bioRxiv2022

UNC-45 assisted myosin folding depends on a conserved FX3HY motif implicated in Freeman Sheldon Syndrome

Myosin motors are critical for diverse motility functions ranging from cytokinesis and endocytosis to muscle contraction. The UNC-45 chaperone controls myosin function mediating the folding, assembly, and degradation of the muscle protein. Here, we analyze the molecular mechanism of UNC-45 as a hub in myosin quality control. We show that UNC-45 forms discrete complexes with folded and unfolded myosin, forwarding them to downstream chaperones and E3 ligases. Structural analysis of a minimal chaperone:substrate complex reveals that UNC-45 binds to a conserved FX3HY motif in the myosin motor domain. Disrupting the observed interface by mutagenesis prevents myosin maturation leading to protein aggregation in vivo. We also show that a mutation in the FX3HY motif linked to the Freeman Sheldon Syndrome impairs UNC-45 assisted folding, reducing the level of functional myosin. These findings demonstrate that a faulty myosin quality control is a critical yet unexplored cause of human myopathies.

biochemistry↗

bioRxiv2021

PermaPhosSer: autonomous synthesis of functional, permanently phosphorylated proteins

Installing stable, functional mimics of phosphorylated amino acids into proteins offers a powerful strategy to study protein regulation. Previously, a genetic code expansion (GCE) system was developed to translationally install non-hydrolyzable phosphoserine (nhpSer), with the {gamma}-oxygen replaced with carbon, but it has seen limited usage. Here, we achieve a 40-fold improvement in this system by engineering into Escherichia coli a biosynthetic pathway that produces nhpSer from the central metabolite phosphoenolpyruvate. Using this "PermaPhosSer" system - an autonomous 21-amino acid E. coli expression system for incorporating nhpSer into target proteins - we show that nhpSer faithfully mimics the effects of phosphoserine in three stringent test cases: promoting 14-3-3/client complexation, disrupting 14-3-3 dimers, and activating GSK3{beta} phosphorylation of the SARS-CoV-2 nucleocapsid protein. This facile access to nhpSer containing proteins should allow nhpSer to replace Asp and Glu as the go-to pSer phosphomimetic for proteins produced in E. coli.

synthetic biology↗

bioRxiv2021

Population genomics of Bacillus anthracis from an anthrax hyperendemic area reveals transmission processes across spatial scales and unexpected within-host diversity

Genomic sequencing has revolutionized our understanding of bacterial disease epidemiology, but remains underutilized for zoonotic pathogens in remote endemic settings. Anthrax, caused by the spore-forming bacterium Bacillus anthracis, remains a threat to human and animal health and rural livelihoods in low- and middle-income countries. While the global genomic diversity of B. anthracis has been well-characterized, there is limited information on how its populations are genetically structured at the scale at which transmission occurs, critical for understanding the pathogens evolution and transmission dynamics. Using a uniquely rich dataset, we quantified genome-wide single nucleotide polymorphisms (SNPs) among 73 B. anthracis isolates derived from 33 livestock carcasses sampled over one year throughout the Ngorongoro Conservation Area, Tanzania, an area hyperendemic for anthrax. Genome-wide SNPs distinguished 22 unique B. anthracis genotypes within the study area. However, phylogeographic structure was lacking, as identical SNP profiles were found throughout the study area, likely the result of the long and variable periods of spore dormancy and long-distance livestock movements. Significantly, divergent genotypes were obtained from spatio-temporally linked cases and even individual carcasses. The high number of SNPs distinguishing isolates from the same host is unlikely to have arisen during infection, as supported by our simulation models. This points to an unexpectedly wide transmission bottleneck for B. anthracis, with an inoculum comprising multiple variants being the norm. Our work highlights that inferring transmission patterns of B. anthracis from genomic data will require analytical approaches that account for extended and variable environmental persistence as well as co-infection. ImportancePathogens transmitted between animals and people affect the health and livelihoods of farmers, particularly in developing countries dependent on livestock. Understanding over what distances these pathogens are transmitted and how they evolve is important to inform control strategies towards reducing disease impacts. Information on the circulation of Bacillus anthracis, which causes the often-lethal disease anthrax, is lacking for settings where the disease is commonplace. Consequently, we examined its genetic variability in an area in Tanzania where anthrax is widespread. We found no clear link between how closely cases were sampled and their genetic similarity. We suspect this lack of congruence is primarily driven by large-scale livestock movements, which control efforts should take into consideration. Another significant finding was the co-occurrence of multiple B. anthracis types within individual hosts, suggesting animals are commonly infected with a mixture of variants. This needs to be accounted for when investigating possible connections between cases.

genomics↗

bioRxiv2020

A prefusion SARS-CoV-2 spike RNA vaccine is highly immunogenic and prevents lung infection in non-human primates

To contain the coronavirus disease 2019 (COVID-19) pandemic, a safe and effective vaccine against the new severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) is urgently needed in quantities sufficient to immunise large populations. In this study, we report the design, preclinical development, immunogenicity and anti-viral protective effect in rhesus macaques of the BNT162b2 vaccine candidate. BNT162b2 contains an LNP-formulated nucleoside-modified mRNA that encodes the spike glycoprotein captured in its prefusion conformation. After expression of the BNT162b2 coding sequence in cells, approximately 20% of the spike molecules are in the one-RBD up, two-RBD down state. Immunisation of mice with a single dose of BNT162b2 induced dose level-dependent increases in pseudovirus neutralisation titers. Prime-boost vaccination of rhesus macaques elicited authentic SARS-CoV-2 neutralising geometric mean titers 10.2 to 18.0 times that of a SARS-CoV-2 convalescent human serum panel. BNT162b2 generated strong TH1 type CD4+ and IFN{gamma}+ CD8+ T-cell responses in mice and rhesus macaques. The BNT162b2 vaccine candidate fully protected the lungs of immunised rhesus macaques from infectious SARS-CoV-2 challenge. BNT162b2 is currently being evaluated in a global, pivotal Phase 2/3 trial (NCT04368728).

immunology↗

bioRxiv2020

The linear ubiquitin chain assembly complex generates heterotypic ubiquitin chains

The linear ubiquitin chain assembly complex (LUBAC) is the only known ubiquitin ligase that generates linear/Met1-linked ubiquitin chains. One of the LUBAC components, HOIL-1L, was recently shown to catalyse oxyester bond formation between the C-terminus of ubiquitin and some substrates. However, oxyester bond formation in the context of LUBAC has not been directly observed. We present the first 3D reconstruction of LUBAC obtained by electron microscopy and report its generation of heterotypic ubiquitin chains containing linear linkages with oxyester-linked branches. We found that addition of the oxyester-bound branches depends on HOIL-1L catalytic activity. We suggest a coordinated ubiquitin relay mechanism between the HOIP and HOIL-1L ligases supported by cross-linking mass spectrometry data, which show proximity between the catalytic RBR domains. Mutations in the linear ubiquitin chain-binding NZF domain of HOIL-1L reduces chain branching confirming its role in the process. In cells, these heterotypic chains were induced by TNF. In conclusion, we demonstrate that LUBAC assembles heterotypic ubiquitin chains with linear and oxyester-linked branches by the concerted action of HOIP and HOIL-1L.

biochemistry↗

bioRxiv2020

Evaluation of cerebellar function scores in relation to cerebellar axonal loss in multiple sclerosis

BackgroundCerebellar damage is common in people with multiple sclerosis (pwMS) and is associated with worse progression and relapse recovery. Studies into the importance of the cerebellum in pwMS are hampered by limited understanding of cerebellar damage and its relation to cerebellar function in pwMS. ObjectiveExamine axonal loss, as a primary driver of progressive neurological decline, in the cerebellum using advanced diffusion MRI and compare axonal loss with cerebellar dysfunction in pwMS MethodsWe recruited 55 pwMS and 14 healthy controls. Clinical assessments included scale for the assessment and rating of ataxia (SARA), and Bain tremor ratings. Subjects underwent FLAIR, T1-weighted and diffusion MRI. Cerebellar grey and white matter and lesion volume were calculated. Cerebellar axonal loss was examined with fibre-specific markers. Fibre density and cross-section (FDC) accounts for microscopic and macroscopic changes in a fibre bundle. ResultsLoss of cerebellar FDC was associated with increased SARA (r=-0.42, p<0.01) and tremor severity (rho=-0.35, p=0.01). Cerebellar lesion volume correlated with SARA (r=0.49, p<0.01) and tremor severity (rho=0.41, p=0.01). ConclusionFibre-specific measures of cerebellar pathology could provide a functionally relevant marker of cerebellar damage in MS. Future trials using fibre-specific markers are needed to further characterize cerebellar pathology in pwMS and understand its significance in disease progression.

neuroscience↗

bioRxiv2020

A Solanum lycopersicoides reference genome facilitates biological discovery in tomato

Wild relatives of tomato are a valuable source of natural variation in tomato breeding, as many can be hybridized to the cultivated species (Solanum lycopersicum). Several, including Solanum lycopersicoides, have been crossed to S. lycopersicum for the development of ordered introgression lines (ILs). Despite the utility of these wild relatives and their associated ILs, limited finished genomes have been produced to aid genetic and genomic studies. We have generated a chromosome-scale genome assembly for Solanum lycopersicoides LA2951 using PacBio sequencing, Illumina, and Hi-C. We identified 37,938 genes based on Illumina and Isoseq and compared gene function to the available cultivated tomato genome resources, in addition to mapping the boundaries of the S. lycopersicoides introgressions in a set of cv. VF36 x LA2951 introgression lines (IL). The genome sequence and IL map will support the development of S. lycopersicoides as a model for studying fruit nutrient/quality, pathogen resistance, and environmental stress tolerance traits that we have identified in the IL population and are known to exist in S. lycopersicoides.

genomics↗

bioRxiv2019

Plant-microbe co-evolution: allicin resistance in a Pseudomonas fluorescens strain (PfAR-1) isolated from garlic

The antibiotic defense substance allicin (diallylthiosulfinate) is produced by garlic (Allium sativum L.) after tissue damage, giving garlic its characteristic odor. Allicin is a redox-toxin that oxidizes thiols in glutathione and cellular proteins. A highly allicin-resistant Pseudomonas fluorescens strain (PfAR-1) was isolated from garlic, and genomic clones were shotgun electroporated into an allicin-susceptible P. syringae strain (Ps4612). Recipients showing allicin-resistance had all inherited a group of genes from one of three similar genomic islands (GI), that had been identified in an in silico analysis of the PfAR-1 genome. A core fragment of 8-10 congruent genes with redox-related functions, present in each GI, was shown to confer allicin-specific resistance to P. syringae, and even to an unrelated E. coli strain. Transposon mutagenesis and overexpression analyses revealed the contribution of individual candidate genes to allicin-resistance. Moreover, PfAR-1 was unusual in having 3 glutathione reductase (glr) genes, two copies in two of the GIs, but outside of the core group, and one copy in the PfAR-1 genome. Glr activity was approximately 2-fold higher in PfAR-1 than in related susceptible Pf0-1, with only a single glr gene. Moreover, an E. coli {Delta}glr mutant showed increased susceptibility to allicin, which was complemented by PfAR-1 glr1. Taken together, our data support a multi-component resistance mechanism against allicin, achieved through horizontal gene transfer during coevolution, and allowing exploitation of the garlic ecological niche. GI regions syntenic with PfAR-1 GIs are present in other plant-associated bacterial species, perhaps suggesting a wider role in adaptation to plants per se.

evolutionary biology↗