Biology subjects

Charpentier, E.

Publications and source records attributed to Charpentier, E..

17 recordsLinked to original sources

bioRxiv2026

The cost-benefit trade-off of peritrichous flagellation in bacteria

Many bacteria assemble multiple flagella, although building flagella imposes a substantial biosynthetic and energetic cost. We used the peritrichously flagellated model organism Salmonella enterica to quantify how flagellar abundance affects bacterial growth, proteome allocation, and motility. For this, we generated genetically modified strains with inducible or constitutive expression of the flagellar master regulator flhDC, resulting in a panel of strains ranging from nearly non-flagellated to hyperflagellated cells. We found that higher flagellar investment reduced growth rate and redirected proteome allocation, with an expansion of the flagellar sector occurring largely at the expense of the ribosomal sector. Growth analyses of flagellar assembly mutants, combined with cost modeling, suggested that flagellin biosynthesis dominated the energetic burden, whereas motor rotation contributed a smaller additional cost. Despite the associated cost, increased flagellation improved soft-agar spreading, single-cell swimming speed, effective diffusivity, and competitive fitness in spatially structured environments. A coarse-grained proteome-allocation model parametrized from these data reproduced the observed growth penalties, while simulations of navigation in dynamic chemical gradients predicted that motility benefits saturate near a flagellar investment of 3% of proteome mass. Beyond this point, rising biosynthetic costs outweigh diminishing motility gains. In summary, these results support a quantitative cost-benefit model in which heterogeneous, spatially structured environments favor an intermediate number of flagella by balancing motility benefits against the biosynthetic costs of building and operating multiple flagella.

microbiology↗

bioRxiv2026

Microbiota-induced fatty acid synthesis facilitates intestinal infection and immune-mediated damage in Drosophila

The role of the microbiota in facilitating infection is increasingly recognized, though the underlying mechanisms remain under investigation. In this study, we demonstrate that the gut microbiome, particularly Lactiplantibacillus plantarum, promotes enteric infection in Drosophila melanogaster by reshaping host physiology and immune responses. Upon gut colonization, L. plantarum enhances fatty acid (FA) production in the gut. Reducing FA synthesis improves host survival, and pathogen mutants deficient in FA utilization exhibit reduced virulence. FAs support pathogen growth, increase virulence, and enhance resistance to antimicrobial effectors, ultimately facilitating pathogen persistence in the gut. Persisting pathogens consequently overstimulate the immune system, leading to excessive production of antimicrobial peptides (AMPs). Flies lacking AMPs, particularly Metchnikowin and Attacin D mutants, show better survival during infection, implicating AMPs in immunopathology. Our findings identify a mechanism whereby microbiota-induced release of host FAs stimulates pathogen virulence and persistence, ultimately driving AMP-mediated immunopathology.

microbiology↗

bioRxiv2025

Targeting the translation machinery: The RNase Y specificity factor Y-complex coordinates ribosome degradation

Limiting the synthesis and activity of ribosomes is crucial for adaptation to stresses, such as heat or nutrient starvation. In Bacillus subtilis, this can be achieved through the coordinated action of the alarmones (p)ppGpp and the transcription factor Spx. Here, we performed a genetic screen to uncover novel factors contributing to the heat shock response of B. subtilis. We identified the Y-complex, which confers specificity to the endonuclease RNase Y, as a critical player during stress conditions, such as heat or transition into stationary phase. This protein complex is required for processing diverse RNAs, notably the maturation of mRNAs encoding proteins involved in translation and metabolism. We further demonstrate that the Y-complex and RNase Y initiate the degradation of rRNAs of mature ribosomes, lowering their abundance. We propose that the Y-complex is a regulatory hub that modulates gene expression, adjusts protein synthesis and resource allocation.

microbiology↗

bioRxiv2024

Novel RNA-binding protein YebC enhances translation of proline-rich amino acid stretches in bacteria

The ribosome employs a set of highly conserved translation factors to efficiently synthesise proteins. Some translation factors interact with the ribosome in a transient manner and are thus challenging to identify. However, proteins involved in translation can be specifically identified by their interaction with ribosomal RNAs. Using a combination of proteomics approaches, we identified novel RNA binding proteins in the pathogenic bacterium Streptococcus pyogenes. One of these, a universally conserved protein YebC, was shown to transiently interact with 23S rRNA near the peptidyl-transferase centre. Deletion of yebC moderately affected the physiology and virulence of S. pyogenes. We performed ribosome profiling and detected increased pausing at proline-rich amino acid stretches in the absence of functional YebC. Further results obtained with in vivo reporters and in vitro translation system suggest that YebC is a novel translation factor required for efficient translation of proteins with proline-rich motifs.

molecular biology↗

bioRxiv2024

Bacterial motility depends on a critical flagellum length and energy-optimised assembly

The flagellum is the most complex macromolecular structure known in bacteria and comprised of around two dozen distinct proteins. The main building block of the long, external flagellar filament, flagellin, is secreted through the flagellar type-III secretion system at a remarkable rate of several tens of thousands amino acids per second, significantly surpassing the rates achieved by other pore-based protein secretion systems. The evolutionary implications and potential benefits of this high secretion rate for flagellum assembly and function, however, have remained elusive. In this study, we provide both experimental and theoretical evidence that the flagellar secretion rate has been evolutionarily optimized to facilitate rapid and efficient construction of a functional flagellum. By synchronizing flagellar assembly, we found that a minimal filament length of 2.5 {micro}m was required for swimming motility. Biophysical modelling revealed that this minimal filament length threshold resulted from an elasto-hydrodynamic instability of the whole swimming cell, dependent on the filament length. Furthermore, we developed a stepwise filament labeling method combined with electron microscopy visualization to validate predicted flagellin secretion rates of up to 10,000 amino acids per second. A biophysical model of flagellum growth demonstrates that the observed high flagellin secretion rate efficiently balances filament elongation and energy consumption, thereby enabling motility in the shortest amount of time. Taken together, these insights underscore the evolutionary pressures that have shaped the development and optimization of the flagellum and type-III secretion system, illuminating the intricate interplay between functionality and efficiency in assembly of large macromolecular structures. Significance statementOur study demonstrates how protein secretion of the bacterial flagellum is finely tuned to optimize filament assembly rate and flagellum function while minimizing energy consumption. By measuring flagellar filament lengths and bacterial swimming after initiation of flag-ellum assembly, we were able to establish the minimal filament length necessary for swimming motility, which we rationalized physically as resulting from an elasto-hydrodynamic instability of the swimming cell. Our bio-physical model of flagellum growth further illustrates how the physiological flagellin secretion rate is optimized to maximize filament elongation while conserving energy. These findings illuminate the evolutionary pressures that have shaped the function of the bacterial flagellum and type-III secretion system, driving improvements in bacterial motility and overall fitness.

microbiology↗

bioRxiv2024

Expanding the genetic toolbox for the obligate human pathogen Streptococcus pyogenes

Genetic tools form the basis for the study of molecular mechanisms. Despite many recent advances in the field of genetic engineering in bacteria, genetic toolsets remain scarce for non-model organisms, such as the obligatory human pathogen Streptococcus pyogenes. In this study, we set out to develop a comprehensive set of plasmids, promoters and reporters for S. pyogenes. We present an expansion to the current genetic toolbox that comprises new replicative and site-specific integrative plasmids. Moreover, we established a collection of constitutive promoters with a wide variety of strengths as well as a set of novel inducible regulatory elements, including a zinc-inducible promoter, an erythromycin-inducible riboswitch and an IPTG-inducible promoter that outperform previously described inducible systems in terms of tightness and inducibility. In addition, we demonstrated the applicability of two codon-optimized fluorescent proteins, mNeongreen and mKate2, as reporters in S. pyogenes. For this, we adapted a novel chemically defined medium called RPMI4Spy. This medium showed a highly reduced autofluorescence compared to other growth media and allowed efficient signal detection in plate reader assays and fluorescence microscopy. Finally, we developed a plasmid-based system for genome engineering in S. pyogenes featuring the counterselection marker pheS*, which improved the generation of scarless gene deletions. This new toolbox simplifies previously laborious genetic manipulation procedures and lays the foundation for new methodologies to study gene functions in S. pyogenes, leading to a better understanding of its virulence mechanisms and physiology.

synthetic biology↗

bioRxiv2024

The energy metabolism of Cupriavidus necator in different trophic conditions

The knallgas bacterium Cupriavidus necator is attracting interest for biotechnological applications due to its extremely versatile metabolism. C. necator can use hydrogen or formic acid as an energy source, fixes CO2 via the Calvin-Benson-Bassham (CBB) cycle, and also grows well on various other organic acids and sugars. Its tri-partite genome is notable for its size and manifold duplications of key genes (CBB cycle, hydrogenases, nitrate reductases). Comparatively little is known about which of these (iso-) enzymes and their cofactors are actually utilized for growth on different energy sources. Here, we investigated the energy metabolism of C. necator H16 by growing a barcoded transposon knockout library on various substrates including succinate, fructose, hydrogen (H2/CO2) and formic acid. The fitness contribution of each gene was determined from enrichment or depletion of the corresponding mutants. Fitness analysis revealed that 1) some, but not all, molybdenum cofactor biosynthesis genes were essential for growth on formate and nitrate respiration. 2) Soluble formate dehydrogenase (FDH) was the dominant enzyme for formate oxidation, not membrane-bound FDH. 3) For hydrogenases, both soluble and membrane-bound enzymes were beneficial for lithoautotrophic growth. 4) Of the six terminal respiratory complexes in C. necator H16, only some are utilized and utilization depends on the energy source. 5) Deletion of hydrogenase-related genes boosted heterotrophic growth, and we show that the relief from associated protein cost is responsible for this phenomenon. This study evaluates the contribution of each of C. necators genes to fitness in biotechnologically relevant growth regimes. Our results illustrate the genomic redundancy of this generalist bacterium, and may inspire future strategies for strain engineering. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=110 SRC="FIGDIR/small/582058v2_ufig1.gif" ALT="Figure 1"> View larger version (46K): org.highwire.dtl.DTLVardef@1aac357org.highwire.dtl.DTLVardef@1fe970corg.highwire.dtl.DTLVardef@16ea53dorg.highwire.dtl.DTLVardef@122498d_HPS_FORMAT_FIGEXP M_FIG C_FIG HighlightsO_LIa barcoded transposon library was used to assess gene fitness for hydrogenase, formate dehydrogenase and electron transport chain complexes C_LIO_LIthe utilization of terminal respiratory complexes is substrate specific C_LIO_LIsoluble formate dehydrogenase is more important than the membrane-bound enzyme C_LIO_LIsoluble hydrogenase and membrane-bound hydrogenase are equally utilized C_LIO_LIinactivation of hydrogenase and its accessory genes leads to faster heterotrophic growth C_LIO_LIwe demonstrate that faster growth is caused by the relief of protein synthesis burden C_LIO_LIfitness data is available in an interactive app at https://m-jahn.shinyapps.io/ShinyLib/ C_LI

microbiology↗

bioRxiv2023

Dynamics of diversified A-to-I editing in Streptococcus pyogenes is governed by changes in mRNA stability

Adenosine-to-inosine (A-to-I) RNA editing plays an important role in the post-transcriptional regulation of eukaryotic cell physiology. However, our understanding of the occurrence, function and regulation of A-to-I editing in bacteria remains limited. Bacterial mRNA editing is catalysed by the deaminase TadA, which was originally described to modify a single tRNA in E. coli. Intriguingly, several bacterial species appear to perform A-to-I editing on more than one tRNA. Here, we provide evidence that in the human pathogen Streptococcus pyogenes, tRNA editing has expanded to an additional tRNA substrate. Using RNA sequencing, we identified more than 27 editing sites in the transcriptome of S. pyogenes SF370 and demonstrate that the adaptation of S. pyogenes TadA to a second tRNA substrate has also diversified the sequence context and recoding scope of mRNA editing. Based on the observation that editing is dynamically regulated in response to several infection-relevant stimuli, such as oxidative stress, we further investigated the underlying determinants of editing dynamics and identified mRNA stability as a key modulator of A-to-I editing. Overall, our findings reveal the presence and diversification of A-to-I editing in S. pyogenes and provide novel insights into the plasticity of the editome and its regulation in bacteria. GRAPHICAL ABSTRACT O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=150 SRC="FIGDIR/small/555891v1_ufig1.gif" ALT="Figure 1"> View larger version (45K): org.highwire.dtl.DTLVardef@15b6ddeorg.highwire.dtl.DTLVardef@18a1bf4org.highwire.dtl.DTLVardef@3154ddorg.highwire.dtl.DTLVardef@ba980a_HPS_FORMAT_FIGEXP M_FIG C_FIG

molecular biology↗

bioRxiv2022

IMPROVED N- AND O-GLYCOPEPTIDE IDENTIFICATION USING HIGH-FIELD ASYMMETRIC WAVEFORM ION MOBILITY SPECTROMETRY (FAIMS)

AO_SCPLOWBSTRACTC_SCPLOWMass spectrometry is the premier tool for identifying and quantifying site-specific protein glycosylation globally. Analysis of intact glycopeptides often requires an enrichment step, after which the samples remain highly complex and exhibit a broad dynamic range of abundance. Here, we evaluated the analytical benefits of high-field asymmetric waveform ion mobility spectrometry (FAIMS) coupled to nano-liquid chromatography mass spectrometry (nLC-MS) for analyses of intact glycopeptide devoid of any enrichment step. We compared the effects of compensation voltage on the transmission of N- and O-glycopeptides derived from heterogeneous protein mixtures using two FAIMS devices. We comprehensively demonstrate the performance characteristics of the FAIMS device for glycopeptide analysis and recommend optimal electrode temperature and compensation voltage (CV) settings for N- and O-glycopeptide analysis. Under optimal CV settings, FAIMS-assisted gas-phase fractionation in conjunction with chromatographic reverse phase separation resulted in a 31% increase in the detection of both N- and O-glycopeptide compared to control experiments without FAIMS. Overall, our results demonstrate that FAIMS provides an alternative means to access glycopeptides without any enrichment providing an unbiased global glycoproteome landscape. In addition, our work provides the framework to verify difficult-to-identify glycopeptide features.

biochemistry↗

bioRxiv2022

A regulatory toolkit of arabinose-inducible artificial transcription factors for Gram-negative bacteria

The Gram-negative bacteria Salmonella Typhimurium and Escherichia coli are important model organisms, powerful prokaryotic expression platforms for biotechnological applications, and pathogenic strains constitute major public health threats. To facilitate new approaches for research, biomedicine, and biotechnological applications, we developed a set of arabinose-inducible artificial transcription factors (ATFs) using CRISPR/dCas9 and Arabidopsis-derived DNA-binding proteins, allowing to control gene expression in E. coli and Salmonella over a wide inducer concentration range. As a proof-of-concept, we employed the developed ATFs to engineer a Salmonella biosensor strain, SALSOR 0.2 (SALmonella biosenSOR 0.2), which responds to the presence of alkaloid drugs with quantifiable fluorescent output. We demonstrated that SALSOR 0.2 was able to detect the presence of the antitussive noscapine alkaloid with ~2.3-fold increased fluorescent signal over background noise compared to a previously described biosensor. Moreover, we used plant-derived ATFs to control {beta}-carotene biosynthesis in E. coli, which resulted in ~1.6-fold higher {beta}-carotene production compared to expression of the biosynthesis pathway using a strong constitutive promoter. The arabinose-inducible ATFs reported here thus enhance the synthetic biology repertoire of transcriptional regulatory modules that allow tuning protein expression in the Gram-negative model organisms Salmonella and E. coli.

synthetic biology↗

bioRxiv2022

Bacillus subtilis remains translationally active after CRISPRi-mediated replication initiation arrest

Initiation of bacterial DNA replication takes place at the origin of replication, a region characterized by the presence of multiple DnaA boxes that serve as the binding sites for the master initiator protein DnaA. The absence or failure of DNA replication can result in bacterial cell growth arrest or death. Here, we aimed to uncover the physiological and molecular consequences of stopping replication in the model bacterium Bacillus subtilis. For this purpose, DNA replication was blocked using a CRISPRi approach specifically targeting DnaA boxes 6 and 7, which are essential for replication initiation. We characterized the phenotype of these cells and analyzed the overall changes in the proteome using quantitative mass spectrometry. Cells with arrested replication were elongating and not dividing but showed no evidence of DNA damage response. Moreover, these cells did not cease translation over time. This study sets the ground for future research on non-replicating but translationally active B. subtilis, which might be a valuable tool for biotechnological applications. ImportanceEven though bacteria are constantly replicating under laboratory conditions, natural environments expose them to various stresses like lack of nutrients, high salinity, and pH changes, which can keep them in non-replicating states. Non-replicating states can allow bacteria to become less sensitive or tolerant to antibiotics (persisters), remain inactive in specific niches for an extended period (dormancy), and adapt to some hostile ecosystems. Non-replicating states have been studied due to the possibility of repurposing energy to produce additional metabolites or proteins. Using CRISPRi targeting bacterial replication initiation sequences, we successfully arrested the replication of B. subtilis. We observed that non-replicating cells continued growing but not dividing, and the initial arrest did not induce global stress conditions such as SOS or stringent response. Notably, these cells continued their metabolic activity and translation. This study provides comprehensive insights into the physiological response of replication initiation blockage in B. subtilis.

microbiology↗

bioRxiv2022

Protein arginine phosphorylation and de-phosphorylation facilitate protein homeostasis by an AAA+ chaperone protease system

We could demonstrate that the AAA+ unfoldase ClpC together with the protein arginine kinase and adaptor protein McsB, its activator McsA and the phosphatase YwlE form a unique chaperone system. Here, the McsA-activated McsB phosphorylates and targets aggregated substrate proteins for extraction and unfolding by ClpC. Sub-stoichiometric amounts of the YwlE phosphatase enhanced the ClpC/McsB/McsA mediated disaggregation and facilitated the de-phosphorylation of the arginine-phosphorylated substrate protein extruded by ClpC, allowing its subsequent refolding. Interestingly, the successfully refolded protein escaped degradation by the loosely associated ClpP protease. This unique chaperone system is thereby able to disaggregate and refold aggregated proteins but can also remove severely damaged protein aggregates by degradation.

microbiology↗

bioRxiv2022

Expanded Distribution and Predicted Suitable Habitat for the Critically Endangered Yellow-tailed Woolly Monkey (Lagothrix flavicauda) in Peru

The Tropical Andes Biodiversity Hotspot holds a remarkable number of species at risk of extinction due to anthropogenic habitat loss, hunting and climate change. One of these species, the Critically Endangered yellow-tailed woolly monkey (Lagothrix flavicauda), was recently sighted in Junin region, 206 kilometres south of its previously known distribution. The range extension, combined with continued habitat loss, calls for a re-evaluation of the species distribution and available suitable habitat. Here, we present novel data from surveys at 53 sites in the regions of Junin, Cerro de Pasco, Ayacucho and Cusco. We encountered L. flavicauda at 9 sites, all in Junin, and the congeneric L. l. tschudii at 20 sites, but never in sympatry. Using these new localities along with all previous geographic localities for the species, we made predictive Species Distribution Models based on Ecological Niche Modelling using a generalized linear model and maximum entropy. Each model incorporated bioclimatic variables, forest cover, vegetation measurements, and elevation as predictor variables. Model evaluation showed >80% accuracy for all measures. Precipitation was the strongest predictor of species presence. Habitat suitability maps illustrate potential corridors for gene flow between the southern and northern populations, although much of this area is inhabited by L. l. tschudii. An analysis of the current protected area (PA) network showed [~]47% of remaining suitable habitat is unprotected. With this, we suggest priority areas for new protected areas or expansions to existing reserves that would conserve potential corridors between L. flavicauda populations. Further surveys and characterization of the distribution in intermediate areas, combined with studies on genetic flow, are still needed to protect this species.

ecology↗

bioRxiv2022

Genetic population structure across Brittany and the downstream Loire basin provides new insights on the demographic history of Western Europe

European genetic ancestry originates from three main ancestral populations - Western hunter-gatherers, early European farmers and Yamnaya Eurasian herders - whose edges geographically met in present-day France. Despite its central role to our understanding of how the ancestral populations interacted and gave rise to modern population structure, the population history of France has remained largely understudied. Here, we analysed the high-coverage whole-genome sequences and genome-wide genotype profiles of respectively 856 and 3,234 present-day individuals from the northern half of France, and merged them with publicly available present-day and ancient Europe-wide genotype datasets. We also explored, for the first time, the whole-genome sequences of six mediaeval individuals (300-1100 CE) from Western France to gain insights into the genetic impact of what is commonly known as the Migration Period in Europe. We found extensive fine-scale population structure across Brittany and the downstream Loire basin, emphasising the need for investigating local populations to better understand the distribution of rare and putatively deleterious variants across space. Overall, we observed an increased population differentiation between the northern and southern sides of the river Loire, which are characterised by different proportions of steppe vs. Neolithic-related ancestry. Samples from Western Brittany carry the largest levels of steppe ancestry and show high levels of allele sharing with individuals associated with the Bell Beaker complex, levels that are only comparable with those found in populations lying on the northwestern edges of Europe. Together, our results imply that present-day individuals from Western Brittany retain substantial legacy of the genetic changes that occurred in Northwestern Europe following the arrival of the Bell Beaker people c. 2500 BCE. Such genetic legacy may explain the sharing of disease-related alleles with other present-day populations from Western Britain and Ireland.

genetics↗

bioRxiv2020

Controlling membrane barrier during bacterial type-III protein secretion

Type-III secretion systems (T3SSs) of the bacterial flagellum and the evolutionarily related injectisome are capable of translocating proteins with a remarkable speed of several thousand amino acids per second. Here, we investigated how T3SSs are able to transport proteins at such a high rate while preventing the leakage of small molecules. Our mutational and evolutionary analyses demonstrate that an ensemble of conserved methionine residues at the cytoplasmic side of the T3SS channel create a deformable gasket (M-gasket) around fast-moving substrates undergoing export. The unique physicochemical features of the M-gasket are crucial to preserve the membrane barrier, to accommodate local conformational changes during active secretion, and to maintain stability of the secretion pore in cooperation with a plug domain (R-plug) and a network of salt-bridges. The conservation of the M-gasket, R-plug, and salt-bridge network suggests a universal mechanism by which the membrane integrity is maintained during high-speed protein translocation in all T3SSs.

microbiology↗

bioRxiv2019

Genetic association analyses highlight IL6, ALPL, and NAV1 as three new susceptibility genes underlying calcific aortic valve stenosis

To date, only two replicated loci, LPA and PALMD, have been identified as causal genes for calcific aortic valve stenosis (CAVS) using genome-wide and transcriptome-wide association study (TWAS). To identify additional susceptibility genes for CAVS, we performed a GWAS meta-analysis totaling 5,115 cases and 354,072 controls of European descent. Four loci achieved genome-wide significance, including two new loci: IL6 (interleukin 6) on 7p15.3 and ALPL (alkaline phosphatase) on 1p36.12. A TWAS integrating an eQTL study of 233 human aortic valves identified NAV1 (neuron navigator 1) on 1q32.1 as a new candidate causal gene. The CAVS risk alleles were associated with higher mRNA expression of NAV1 in valve tissues. Association results at the genome-wide scale showed genetic correlation with coronary artery disease and cardiovascular risk factors. Our study highlights three new loci implicating inflammation, mineralization and blood vessel integrity in CAVS pathogenesis and supports shared genetic etiology with cardiovascular traits.

genomics↗

bioRxiv2017

Functionally Convergent B Cell Receptor Sequences in Transgenic Rats Expressing a Human B Cell Repertoire in Response to Tetanus Toxoid and Measles Antigens

The identification and tracking of antigen-specific immunoglobulin (Ig) sequences within total Ig repertoires is central to high-throughput sequencing (HTS) studies of infections or vaccinations. In this context, public Ig sequences shared by different individuals exposed to the same antigen could be valuable markers for tracing back infections, measuring vaccine immunogenicity, and perhaps ultimately allow the reconstruction of the immunological history of an individual. Here, we immunized groups of transgenic rats expressing human Ig against tetanus toxoid (TT), Modified Vaccinia virus Ankara (MVA), measles virus hemagglutinin and fusion proteins expressed on MVA and the environmental carcinogen Benzo[a]Pyrene, coupled to TT. We showed that these antigens impose a selective pressure causing the Ig Heavy chain (IgH) repertoires of the rats to converge towards the expression of antibodies with highly similar IgH CDR3 amino acid sequences. We present a computational approach, similar to differential gene expression analysis, that selects for clusters of CDR3s with 80% similarity, significantly overrepresented within the different groups of immunized rats. These IgH clusters represent antigen-induced IgH signatures exhibiting stereotypic amino acid patterns including previously described TT and measles specific IgH sequences. Our data suggest, that with the presented methodology, transgenic Ig rats can be utilized as a model to identify antigen-induced, human IgH signatures to a variety of different antigens.

immunology↗