Biology subjects

Guo, L.

Publications and source records attributed to Guo, L..

At least 181 records · Page 10Linked to original sources

bioRxiv2021

Numb is required for optimal contraction of skeletal muscle

BackgroundThe role of Numb, a protein that is important for cell fate and development was investigated in adult skeletal muscle in mice using a conditional, inducible knockout (cKO) model. MethodsNumb expression was evaluated by Western blot. Numb localization was determined by confocal microscopy. The effects of cKO of Numb and the closely-related gene Numb-like in skeletal muscle fibers was evaluated by in-situ physiology; transmission and focused ion beam scanning electron microscopy; 3-dimensional reconstruction of mitochondrial; lipidomics; and bulk RNA-sequencing. Additional studies using primary mouse myotubes investigated the effects the effects of Numb knockdown on cell fusion, mitochondrial function and calcium transients. ResultsNumb protein expression was reduced by [~]70% (p < 0.01) at 24 as compared to 3 months of age. Numb was localized within muscle fibers as bands traversing fibers at regularly spaced intervals in close proximity to dihydropyridine receptors. The cKO of Numb and Numb-like reduced specific tetanic force by 36%, p < 0.01), altered mitochondrial spatial relationships to sarcomeric structures, increased Z-line spacing by 30% (p < 0.0001), perturbed sarcoplasmic reticulum organization and reduced mitochondrial volume by over 80% (p < 0.01). Only six genes were differentially expressed in cKO mice: Itga4, Sema7a, Irgm2, Vezf1, Mib1 and Tmem132a. Several lipid mediators derived from polyunsaturated fatty acid (PUFAs) through lipoxygenases were upregulated in Numb cKO skeletal muscle; 12-HEPE was increased by [~]250% (p < 0.05) and 17,18-EpETE by [~]240% (p < 0.05). In mouse primary myotubes, Numb knock-down reduced cell fusion ([~]20%, p < 0.01) and mitochondrial function and delayed the caffeine-induced rise in cytosolic calcium concentrations by more than 100% (p < 0.01). ConclusionsThese findings implicate Numb as a critical factor in skeletal muscle structure and function which appear to be critical for calcium release; we therefore speculate Numb plays critical roles in excitation-contraction coupling, one of the putative targets of aged skeletal muscles. These findings provide new insights into the molecular underpinnings of the loss of muscle function observed with sarcopenia.

physiology↗

bioRxiv2021

A Gene Replacement Humanization Platform for Rapid Functional Testing of Clinical Variants in Epilepsy-associated STXBP1.

PurposeFunctional evidence is a pillar of variant interpretation according to ACMG guidelines. Functional evidence can be obtained in a variety of models and assay systems, including patient-derived tissues and iPSCs, in vitro cellular assays, and in vivo assays. Here we evaluate the reliability and practicality of variant interpretation in the small animal model, C. elegans, through a series of experiments evaluating the function of syntaxin binding protein, STXBP1, a well-known causative gene for Early infantile epileptic encephalopathy 1 (EIEE1). MethodsUsing CRISPR, we replaced the coding sequence for unc-18 with the coding sequence for the human ortholog STXBP1. Next, we used CRISPR to introduce precise point mutations in the human STXBP1 coding sequence, reflecting three clinical categories (benign, pathogenic, and variants of uncertain significance (VUS)). We quantified 26 features of the resulting worms movement to train Random Forest (RF) and Support Vector Machines (SVM) machine learning classifiers on known pathogenic and benign variants. We characterized the classifiers, and then used the behavioral data from the VUS-expressing animals to predict the categorization of the VUS. ResultsWhereas knock-out worms without unc-18 are severely impaired in motor function, worms expressing STXBP1 in its place have restored motor function. We produced worms with STXBP1 variants previously classified by ACMG criteria, including 25 benign variants, 32 pathogenic, and 24 variants of uncertain significance (VUS). Using either SVM or RF classifiers, we were able to obtain a sensitivity of 0.84-0.97 on known benign and pathogenic strains. By comparing multiple ML classification methods, we were able to classify 9 of the VUS as functionally abnormal, suggesting that these VUS are likely to be pathogenic. ConclusionsWe demonstrate that automated analysis of a small animal system is an effective, scalable, and fast way to understand functional consequences of variants in STXBP1, one of the most common causes of genetic epilepsies and neurodevelopmental disorders.

genetics↗

bioRxiv2021

A bacterial dynamin-like protein confers a novel phage resistance strategy on the population level in Bacillus subtilis

Bacillus subtilis DynA is a member of the dynamin superfamily, involved in membrane remodeling processes. DynA was shown to catalyze full membrane fusion and it plays a role in membrane surveillance against antibiotics. We show here that DynA also provides a novel resistance mechanism against phage infection. Cells lacking DynA are efficiently lysed after phage infection and virus replication. DynA does not prevent phage infection and replication in individual cells, but significantly delays host cell lysis, thereby slowing down the release of phage progeny from the host cells. During the process, DynA forms large, almost immobile clusters on the cell membrane that seem to support membrane integrity. Single molecule tracking revealed a shift of freely diffusive molecules within the cytosol towards extended, confined motion at the cell membrane following phage induction. Thus, the bacterial dynamins are the first anti-phage system reported to delay host cell lysis and the last line of defense of a multilayered antiviral defense. DynA is therefore providing protective effects on the population, but not on single cell level.

microbiology↗

bioRxiv2021

PHARP: A pig haplotype reference panel for genotype imputation

Pigs not only function as a major meat source worldwide but also are commonly used as an animal model for studying human complex traits. A large haplotype reference panel has been used to facilitate efficient phasing and imputation of relatively sparse genome-wide microarray chips and low-coverage sequencing data. Using the imputed genotypes in the downstream analysis, such as GWASs, TWASs, eQTL mapping and genomic prediction (GS), is beneficial for obtaining novel findings. However, currently, there is still a lack of publicly available and high-quality pig reference panels with large sample sizes and high diversity, which greatly limits the application of genotype imputation in pigs. In response, we built the pig Haplotype Reference Panel (PHARP) database. PHARP provides a reference panel of 2,012 pig haplotypes at 34 million SNPs constructed using whole-genome sequence data from more than 49 studies of 71 pig breeds. It also provides Web-based analytical tools that allow researchers to carry out phasing and imputation consistently and efficiently. PHARP is freely accessible at http://alphaindex.zju.edu.cn/PHARP/index.php. We demonstrate its applicability for pig commercial 50K SNP arrays, by accurately imputing 2.6 billion genotypes at a concordance rate value of 0.971 in 81 Large White pigs (~ 17x sequencing coverage). We also applied our reference panel to impute the low-density SNP chip into the high-density data for three GWASs and found novel significantly associated SNPs that might be casual variants.

genomics↗

bioRxiv2021

Genomic insights into longan evolution from a chromosome-level genome assembly and population analysis of longan accessions

Longan (Dimocarpus longan) is a subtropical fruit best known for its nutritious fruit and regarded as a precious tonic and traditional medicine since ancient times. High-quality chromosome-scale genome assembly is valuable for functional genomic study and genetic improvement of longan. Here, we report a chromosome-level reference genome sequence for longan cultivar JDB with an assembled genome of 455.5 Mb in size anchored to fifteen chromosomes, representing a significant improvement of contiguity (contig N50=12.1 Mb, scaffold N50= 29.5 Mb) over a previous draft assembly. A total of 40,420 protein-coding genes were predicted in D. longan genome. Synteny analysis suggests longan shares the widespread gamma event with core eudicots, but has no other whole genome duplications. Comparative genomics showed that D. longan genome experienced significant expansions of gene families related to phenylpropanoid biosynthesis and UDP-glucosyltransferase. Deep genome sequencing analysis of longan cultivars identified longan biogeography as a major contributing factor for genetic diversity, and revealed a clear population admixture and introgression among cultivars of different geographic origins, postulating a likely migration trajectory of longan overall confirmed by existing historical records. Finally, genome-wide association studies (GWAS) of longan cultivars identified quantitative trait loci (QTL) for six different fruit quality traits and revealed a shared QTL containing three genes for total soluble solid and seed weight. The chromosome-level reference genome assembly, annotation and population genetic resource for D. longan will facilitate the molecular studies and breeding of desirable longan cultivars in the future.

genomics↗

bioRxiv2021

Island-specific evolution of a sex-primed autosome in the planarian Schmidtea mediterranea

The sexual biotype of the planarian Schmidtea mediterranea is a hermaphrodite indigenous to Tunisia and several Mediterranean islands. Here, we isolated individual chromosomes and used sequencing, Hi-C and linkage mapping to assemble a chromosome-scale genome reference. The linkage map revealed an extremely low rate of recombination on chromosome 1. We confirmed suppression of recombination on chromosome 1 by quantifying recombination events in individual sperm and oocytes. We showed that the extensive heterozygous regions, previously designated as J and V haplotypes, comprise essentially all of chromosome 1. Genome sequencing of individuals isolated in the wild indicated that this heterozygosity has evolved specifically in populations from Sardinia and Corsica. We found that chromosome 1 acquired many genes that determine the development of female and male reproductive systems, along with haplotype-specific expression of such sex specific genes. These molecular signatures and restricted recombination in a hermaphrodite led us to propose that chromosome 1 is a sex-primed autosome, providing direct molecular evidence for the traditional model of how sex chromosomes may have evolved from autosomes.

genetics↗

bioRxiv2021

Sub-lethal radiation-induced senescence impairs resolution programs and drives cardiovascular inflammation

Radiation is associated with tissue damage and increased risk of atherosclerosis but there are currently no treatments and a very limited mechanistic understanding of how radiation impacts tissue repair mechanisms. We uncovered that radiation significantly delayed temporal resolution programs that was associated with decreased efferocytosis in vivo. Resolvin D1 (RvD1), a known pro-resolving ligand, promoted swift resolution and restored efferocytosis in sub-lethally irradiated mice. Irradiated macrophages exhibited several features of senescence, including increased expression of p16INK4A and p21, heightened levels of SA-{beta}-gal, COX-2, and oxidative stress (OS) in vitro, and when transferred to mice exacerbated inflammation in vivo. Mechanistically, heightened OS in senescent macrophages led to impairment in their ability to carry out efficient efferocytosis and treatment with RvD1 reduced OS and improved efferocytosis. Sub-lethally irradiated Ldlr-/- mice exhibited increased plaque necrosis and p16INK4A cells compared with non-irradiated controls and treatment with RvD1 significantly reduced these endpoints. Removal of p16INK4A hematopoietic cells during advanced atherosclerosis with p16-3MR mice reduced plaque necrosis and increased production of key intraplaque resolving mediators. Our results demonstrate that sub-lethal radiation drives macrophage senescence and efferocytosis defects and suggest that RvD1 may be a new therapeutic strategy to limit radiation-induced tissue damage.

immunology↗

bioRxiv2021

The Taxus genome provides insights into paclitaxel biosynthesis

The ancient gymnosperm genus Taxus is the exclusive source of the anticancer drug paclitaxel, yet no reference genome sequences are available for comprehensively elucidating the paclitaxel biosynthesis pathway. We have completed a chromosome-level genome of Taxus chinensis var. mairei with a total length of 10.23 Gb. Taxus shared an ancestral whole-genome duplication with the coniferophyte lineage and underwent distinct transposon evolution. We discovered a unique physical and functional grouping of CYP725As (cytochrome P450) in the Taxus genome for paclitaxel biosynthesis. We also identified a gene cluster in the taxadiene biosynthesis, which was mainly formed by gene duplications. This study will facilitate the elucidation of paclitaxel biosynthesis and unleash the biotechnological potential of Taxus. One Sentence SummaryA chromosome-level genome assembly of Taxus chinensis var. mairei uncovers its unique genome evolution process and genetic architectures for the paclitaxel biosynthesis pathway.

genomics↗

bioRxiv2021

Structural variants contribute to pangenome evolution of a plant pathogenic fungus

Genetic variation is the driving force of plant-pathogen co-evolution. Large-scale genetic variations such as structural variations (SVs) often alter genome stability and organismal fitness. However, the pangenomic landscape and functional implications of SVs remain largely unexplored in plant pathogens. Here, we characterized the pangenomic and SV landscape in wheat head blight fungus Fusarium graminearum by producing and comparing chromosome-level (average contig N50 of 8.9 Mb) genome assemblies of 98 accessions using a reference-guided approach. Accounting for 29.05% and 19.01% of F. graminearum pangenome, respectively, accessory and private genomes are enriched with functions related to membrane trafficking, metabolism of fatty acids and tryptophans, with the private also enriched with putative effectors. Furthermore, using chromosome-level assemblies, we detected 52,420 SVs, 69.51% of which are inaccessible using read-mapping based approach. Over a half (55.65%) of 52,645 merged SVs affected 1,660 protein-coding genes, the most variable of which are involved in fungal virulence, cellular contact and communications. Interestingly, highly variable effectors and secondary metabolic enzymes are co-localized with SVs at subtelomeric and centromeric regions. Collectively, this landmark study shows the prevalence and functional relevance of SVs in F. graminearum, providing a valuable resource for future pangenomic studies in this cosmopolitan pathogen of cereal crops.

genomics↗

bioRxiv2021

Circular RNA Vaccines against SARS-CoV-2 and Emerging Variants

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and its emerging variants of concern (VOC), such as Delta (B.1.617.2) and Omicron (B.1.1.529), has continued to drive the worldwide pandemic. Therefore, there is a high demand for vaccines with enhanced efficacy, high thermostability, superior design flexibility, and fast manufacturing speed. Here, we report a circular RNA (circRNA) vaccine that encodes the trimeric RBD of SARS-CoV-2 Spike protein. Without the need of nucleotide modification, 5-capping or 3-polyadenylation, circRNA could be rapidly produced via in vitro transcription and is highly thermostable whether stored in naked or lipid-nanoparticle (LNP)-encapsulated format. LNP-encapsulated circRNARBD elicited potent neutralizing antibodies and T cell responses, providing robust protection against Beta (B.1.351) and native viruses in mice and rhesus macaques, respectively. Notably, circRNA vaccine enabled higher and more durable antigen production than 1m{Psi}-modified mRNA vaccine, eliciting a higher proportion of neutralizing antibodies and stronger Th1-biased immune responses. Importantly, we found that circRNARBD-Omicron vaccine induced effective neutralizing antibodies against only Omicron but not Delta variant. By contrast, circRNARBD-Delta could elicit high level of neutralizing antibodies against both Delta and Omicron. Following two doses of either native- or Delta-specific vaccination, circRNARBD-Delta, but not Omicron or Beta vaccines, could effectively boost the neutralizing antibodies against both Delta and Omicron variants. These results suggest that circRNARBD-Delta is a favorable choice for vaccination to provide a broad-spectrum protection against the current variants of concern of SARS-CoV-2.

immunology↗

bioRxiv2021

Integrin α6 upregulation in nucleus pulposus cell under high oxygen tension attenuates intervertebral disc degeneration

The destruction of low oxygen microenvironment played critical roles in the pathogenesis of intervertebral disk degeneration (IVDD). In this study, high oxygen tension (HOT) treatment upregulated integrin 6(ITG 6) expression, which could be alleviated by blocking PI3K/AKT signaling pathway. And the levels of ITG 6 expression were increased in the NP tissue from IVDD patients and IVDD rat model with mild degeneration, which were reduced as degeneration degree increases. Further studies found that ITG 6 could protect NP cells against HOT-induced apoptosis and oxidative stress, and protect NP cells from HOT-inhibited ECM proteins synthesis. ITG 6 upregulation by HOT contributed to maintain a NP tissue homeostasis through the interaction with hypoxia inducible factor-1 (HIF-1). Furthermore, silencing of ITG 6 in vivo could obviously accelerate puncture-induced IVDD. Taken together, ITG 6 upregulation by HOT in NP cells might be a protective factor in IVDD as well as restore NP cell function.

cell biology↗

bioRxiv2021

Metatranscriptomic comparison of endophytic and pathogenic Fusarium-Arabidopsis interactions reveals plant transcriptional plasticity

Plants are continuously exposed to beneficial and pathogenic microbes, but how plants recognize and respond to friends versus foes remains poorly understood. Here, we compared the molecular response of Arabidopsis thaliana independently challenged with a Fusarium oxysporum endophyte Fo47 versus a pathogen Fo5176. These two Fusarium oxysporum strains share a core genome of about 46 Mb, in addition to unique 1,229 and 5,415 accessory genes. Metatranscriptomic data reveal a shared pattern of expression for most plant genes ([~]80%) in responding to both fungal inoculums at all time points from 12 to 96 h post inoculation (HPI). However, the distinct responding genes depict transcriptional plasticity, as the pathogenic interaction activates plant stress responses and suppresses plant growth/development related functions, while the endophytic interaction attenuates host immunity but activates plant nitrogen assimilation. The differences in reprogramming of the plant transcriptome are most obvious in 12 HPI, the earliest time point sampled and are linked to accessory genes in both fungal genomes. Collectively, our results indicate that the A. thaliana and F. oxysporum interaction displays both transcriptome conservation and plasticity in the early stages of infection, providing insights into the fine-tuning of gene regulation underlying plant differential responses to fungal endophytes and pathogens. One-sentence summaryMultiomics analysis reveals the regulatory plasticity of plants in response to beneficial and antagonistic microbes, resulting in distinct phenotypes and rewired transcriptional networks.

plant biology↗

bioRxiv2021

Mako: a graph-based pattern growth approach to detect complex structural variants

Complex structural variants (CSVs) are genomic alterations that have more than two breakpoints and are considered as simultaneous occurrence of simple structural variants. However, detecting the compounded mutational signals of CSVs is challenging through a commonly used model-match strategy. As a result, there has been limited progress for CSV discovery compared with simple structural variants. We systematically analyzed the multi-breakpoint connection feature of CSVs, and proposed Mako, utilizing a bottom-up guided model-free strategy, to detect CSVs from paired-end short-read sequencing. Specifically, we implemented a graph-based pattern growth approach, where the graph depicts potential breakpoint connections and pattern growth enables CSV detection without predefined models. Comprehensive evaluations on both simulated and real datasets revealed that Mako outperformed other algorithms. Notably, validation rates of CSV on real data based on experimental and computational validations as well as manual inspections are around 70%, where the medians of experimental and computational breakpoint shift are 13bp and 26bp, respectively. Moreover, Mako CSV subgraph effectively characterized the breakpoint connections of a CSV event and uncovered a total of 15 CSV types, including two novel types of adjacent segments swap and tandem dispersed duplication. Further analysis of these CSVs also revealed impact of sequence homology in the formation of CSVs. Mako is publicly available at https://github.com/jiadong324/Mako.

bioinformatics↗

bioRxiv2021

Human microglia extensively reconstitute in humanized BLT mice with human interleukin-34 transgene and support HIV-1 brain infection

Humanized bone marrow-liver-thymic (hu-BLT) mice develop a functional immune system in periphery but have a limited reconstitution of human myeloid cells, especially microglia, in CNS. Further, whether bone marrow derived hematopoietic stem and progenitor cells (HSPCs) can enter the brain and differentiate into microglia in adults remains controversial. To close these gaps, in this study we unambiguously demonstrated that human microglia in CNS were extensively reconstituted in adult NOG mice with human interleukin-34 transgene (hIL34 Tg) from circulating CD34+ HSPCs but no in hu-BLT NOG mice, providing strong evidence that human CD34+ HSPCs can enter adult brain and differentiate into microglia in CNS in the presence of hIL34. Further, the human microglia in the CNS of hu-BLT-hIL34 NOG mice robustly supported HIV-1 infection reenforcing the notion that microglia are the most important target cells of HIV-1 in CNS and demonstrating its great potential as an in vivo model for studying HIV-1 pathogenesis and evaluating curative therapeutics in both periphery and CNS compartments.

microbiology↗

bioRxiv2021

ENHANCED GRAVITROPISM 2 encodes a STERILE ALPHA MOTIVE containing protein that controls root growth angle in barley and wheat

The root growth angle defines how roots grow towards the gravity vector and is among the most important determinants of root system architecture. It controls water uptake capacity, nutrient use efficiency, stress resilience and as a consequence yield of crop plants. We demonstrated that the egt2 (enhanced gravitropism 2) mutant of barley exhibits steeper root growth of seminal and lateral roots and an auxin independent higher responsiveness to gravity compared to wild type plants. We cloned the EGT2 gene by a combination of bulked segregant analysis and whole genome sequencing. Subsequent validation experiments by an independent CRISPR/Cas9 mutant allele demonstrated that egt2 encodes a STERILE ALPHA MOTIF domain containing protein. In situ hybridization experiments illustrated that EGT2 is expressed from the root cap to the elongation zone. Subcellular localization experiments revealed that EGT2 localizes to the nucleus and cytoplasm. We demonstrated the evolutionary conserved role of EGT2 in root growth angle control between barley and wheat by knocking out the EGT2 orthologs in the A and B genomes of tetraploid durum wheat. By combining laser capture microdissection with RNA-seq, we observed that seven expansin genes were transcriptionally downregulated in the elongation zone. This is consistent with a role of EGT2 in this region of the root where the effect of gravity sensing is executed by differential cell elongation. Our findings suggest that EGT2 is an evolutionary conserved regulator of root growth angle in barley and wheat that could be a valuable target for root-based crop improvement strategies in cereals. Significance StatementTo date the potential of utilizing root traits in plant breeding remains largely untapped. In this study we cloned and characterized the ENHANCED GRAVITROPISM2 (EGT2) gene of barley that encodes a STERILE ALPHA MOTIF domain containing protein. We demonstrated that EGT2 is a key gene of root growth angle regulation in response to gravity which is conserved in barley and wheat and could be a promising target for crop improvement in cereals.

plant biology↗

bioRxiv2021

Impaired sleep-dependent consolidation after stroke - interaction of slow waves, rehabilitation and GABA

Sleep is known to be important for promoting recovery after brain injuries such as stroke. Yet, it remains unclear how such injuries affect neural processing during sleep and how to precisely enhance sleep-dependent memory processing during recovery. Using an experimental model of focal cortical stroke in rats along with long-term electrophysiological monitoring of neural firing and sleep microarchitecture, here we show that sleep-dependent neural processing is altered after stroke induction. Specifically, we found that the precise coupling of spindles to global slow- oscillations (SO), a phenomenon that is known to be important for memory consolidation, appeared to be disrupted by a pathological increase in "isolated" local delta waves. The transition from this pathological to a more physiological sleep state - with both a reduction in isolated delta waves and increased spindle coupling to SO - was associated with sustained performance gains after task training during recovery. Interestingly, post-injury sleep processing could be pushed towards a more physiological state via a pharmacological reduction of tonic GABA. Together, our results suggest that sleep processing after cortical brain injuries may be impaired due to an increase in local delta waves and that restoration of physiological processing is important for recovery of task performance.

neuroscience↗

bioRxiv2020

Genetics of white color and iridophoroma in "Lemon Frost" leopard geckos

The squamates (lizards and snakes) are close relatives of birds and mammals, with more than 10,000 described species that display extensive variation in a number of important biological traits, including coloration, venom production, and regeneration. Due to a lack of genomic tools, few genetic studies in squamates have been carried out. The leopard gecko1, Eublepharis macularius, is a popular companion animal, and displays a variety of coloration patterns. We took advantage of a large breeding colony and used linkage analysis, synteny, and homozygosity mapping to investigate a spontaneous semi-dominant mutation, "Lemon Frost", that produces white coloration and causes skin tumors (iridophoroma). We localized the mutation to a single locus which contains a strong candidate gene, SPINT12,3, a tumor suppressor implicated in human skin cutaneous melanoma (SKCM) and over-proliferation of epithelial cells in mice and zebrafish4-16. Our work establishes the leopard gecko as a tractable genetic system and suggests that a tumor suppressor in melanocytes in humans can also suppress tumor development in iridophores in lizards.

genetics↗

bioRxiv2020

New insight into bacterial iron competition: A-to-I editing in ferric enterobactin uptake

Adenosine-to-inosine (A-to-I) RNA editing, which is catalyzed by the adenosine deaminase RNA-specific family of enzymes, is a frequent post-transcriptional modification in metazoans. Research on A-to-I editing in bacteria is limited, and the importance is underestimated. In this study, we show that bacteria may use A-to-I editing as an alternative strategy to promote uptake of metabolic iron. The T408A editing event of xfeA in Xanthomonas oryzae pv. oryzicola (Xoc) senses extracytoplasmic iron and changes the hydrogen bonding network of ligand channel domains. The frequency of A-to-I RNA editing during iron-deficient conditions increased by 76.87%, which facilitated the passage of iron through the XfeA outer membrane channel. When bacteria were subjected to high iron concentrations, the percentage of A-to-I editing in xfeA decreased, which reduced iron transport via XfeA. Furthermore, A-to-I RNA editing increased expression of multiple genes in the chemotaxis pathway, including methyl-accepting chemotaxis proteins (MCPs) that sense concentrations of exogenous ferric enterobactin (Fe-Ent) at the cytoplasmic membrane. A-to-I RNA editing helps Xoc move towards an iron-rich environment and supports our contention that editing in xfeA facilitates entry of a ferric siderophore. Overall, our results reveal a new signaling mechanism that bacteria use to facilitate iron uptake and improve their competitiveness.

microbiology↗