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Insects living in nutritionally poor environments often establish long-term relationships with intracellular bacteria that supplement their diets and improve their adaptive and invasive powers. Even though these symbiotic associations have been extensively studied on physiological, ecological and evolutionary levels, few studies have focused on the molecular dialogue between host and endosymbionts to identify genes and pathways involved in endosymbiosis control and dynamics. We simultaneously analyzed host and endosymbiont gene expression during the life cycle of the cereal weevilSitophilus oryzae, from larval stages to adults, with a particular emphasis on emerging adults where the endosymbiontSodalis pierantoniusexperiences a contrasted growth-climax-elimination dynamics. We unraveled a constant arms race in which different biological functions are intertwined and coregulated across both partners. These include immunity, metabolism, metal control, apoptosis, and bacterial stress response. Particularly, genes from the Hippo regulatory pathway are specifically induced by endosymbiont growth, while the regulation of metal ions constitutes the basis of the arms race between the two partners at the onset of the bacterial load climax. The study of these tightly regulated functions, which are at the center of symbiotic regulations, provides evidence on how hosts and bacteria finely tune their gene expression and respond to different physiological challenges constrained by insect development in a nutritionally limited ecological niche.Graphical Abstract

Promyelocytic leukemia (PML) has been implicated in a variety of functions, including control of TP53 function and modulation of cellular senescence. Sumolated PML is the organizer of mature PML bodies, recruiting a variety of proteins onto these nuclear domains. The PML gene is predicted to encode a variety of protein isoforms. Overexpression of only one of them, PML-IV, promotes senescence in human diploid fibroblasts, whereas PML-III was proposed to specifically interact with the centrosome. We show that all PML isoform proteins are expressed in cell lines or primary cells. Unexpectedly, we found that PML-III, PML-IV, and PML-V are quantitatively minor isoforms compared with PML-I/II and could not confirm the centrosomal targeting of PML-III. Stable expression of each isoform, in a pml-null background, yields distinct subcellular localization patterns, suggesting that, like in other RBCC/TRIM proteins, the COOH-terminal domains of PML are involved in interactions with specific cellular components. Only the isoform-specific sequences of PML-I and PML-V are highly conserved between man and mouse. That PML-I contains all conserved exons and is more abundantly expressed than PML-IV suggests that it is a critical contributor to PML function(s). (Cancer Res 2006; 66(12): 6192-8)

Supplementary Figures from Characterization of Endogenous Human Promyelocytic Leukemia Isoforms

Supplementary Table from Characterization of Endogenous Human Promyelocytic Leukemia Isoforms

To date, no validated assessment of motor imagery (MI) ability with temporomandibular disorders (TMD) exists preventing identification of good imagers and appropriate MI use during TMD rehabilitation.To assess the reliability and construct validity of the previously developed Tongue and Mouth Imagery Questionnaire (TMIQ) compared with the gold-standard Kinaesthetic and Visual Imagery Questionnaire (KVIQ-10).Both KVIQ-10 and TMIQ assess MI ability using vividness (i.e. clarity/brightness for visual MI,A total of 94 participants were included (n = 47 per group). The mean vividness scores of the KVIQ-10 and the TMIQ were significantly correlated, and not significantly different for both groups indicating concurrent validity. ICCs in the control group (range: 0.82-0.90), and in the TMD group (range: 0.75-0.82) indicated good reproducibility. The Cronbach ⍺ values were all above 0.94, indicating excellent reliability. Two factors were extracted corresponding toThe TMIQ is a valid and reproducible MI questionnaire showing excellent internal consistency and, therefore, can be used to assess imagined movements of the TM region in healthy individuals and patients with TMD.

Maintaining hydraulic structures such as dams, penstocks, or water lock gates in operating conditions and optimizing their maintenance costs are key issues for energy production or river navigation. The ultimate objective is to know the real state of fatigue and damage of the structure and identify any related anomalies. In this paper, we introduce a digital twin, for fatigue evaluation merging measured data obtained with an embedded sensor network and a 3D numerical model that converts in real time measured data into fatigue. After 3 years of R&D collaboration between CNR and Morphosense in the maintenance of navigation lock gates or dam gates, this presentation exposes how the proposed Live Digital Twin solution contributes to fatigue evaluation and more generally to global structural monitoring in dealing with fundamental issues of hydraulic structures: risk assessment, maintenance in operating conditions and maintenance costs optimization. After a context and state of the art introduction, the second part will detail the system overview. In the third part, the monitoring system will be addressed.

International audience; Studies on phytopathogenic bacteria have so far been performed on laboratory strains. The aim of our project is to identify virulence factors of phytopathogenic bacteria isolated from the environment as well as those allowing their survival in water. For this purpose, we use Tn-seq, an innovative mutagenesis technique coupled with high throughput sequencing chosen to rapidly identify, on a large panel of strains, genes necessary for growth in a given condition, the plant or water. This study is carried out on strains of Dickeya, Pectobacterium and Pseudomonas syringae, all of which are capable of growing on a wide range of hosts as well as in water, thus allowing the most complete identification of genes of interest. Another axis of this ANR is the development of a complete bioinformatics pipeline, allowing to process data obtained under multiple conditions and for strains of different species. The results obtained will help us to predict the virulence of strains and/or to develop antibacterial strategies. Overall, this project will pave the way for studies of other environmental pathogens by proposing an original conceptual and technological framework that is extremely promising

International audience

Face aux changements institutionnels en cours dans les centres de jours en France, l’eclairage de la philosophie du Retablissement (Pachoud, 2012) permet au Centre Colbert (Pole Paris 12) de se concentrer sur le sens de ses missions et ses pratiques, pour depasser les clivages entre « tradition » et « modernite ». En soutenant l’espoir, l’empowerment, le sens des responsabilites, le soutien social et la transition identitaire des personnes concernees par un trouble psychique accompagnees, c’est toute une institution qui s’engage dans le processus de Retablissement.

Objective To evaluate the effect of a single session of tDCS over the primary motor cortex of the lower limb (M1-LL) vs. placebo on the walking performance in chronic hemiplegic patients. Patients and methods Randomized, cross-over, double-blinded study. Eighteen patients with initially complete hemiplegia and poststroke delay >6 months were included. Each patient received a single session of anodal stimulation (2 mA, 20 min) over M1-LL (a-tDCS condition) and a pseudostimulation session (SHAM condition). The order of the two sessions was randomly assigned, with an 11-day interval between the two sessions. The anodal electrode was centered on the hotspot identified with Transcranial magnetic stimulation. The cathode was placed above the contralesional orbitofrontal cortex. Walking performance was evaluated with the Wade test and the 6-minute walk test (6MWT), gait parameters with GAITRite, and balance with posturography. These tests were performed during and 1 hour after the stimulation. Baseline assessments were performed the day before and 10 days after each session. Results The comparison between the 6MWT under a-tDCS vs. SHAM conditions demonstrated a nonsignificant positive effect of the stimulation by 15% during stimulation (p = 0.360) and a significant positive effect of 25% 1 hour after stimulation (p = 0.038). No significant differences were observed for the other evaluations. Discussion These results showed a significant positive effect of a single session of anodal tDCS of the M1-LL in chronic hemiplegic patients. This proof-of-concept study supports the conduct of clinical studies evaluating the effectiveness of a walking training program associated with iterative tDCS stimulation. Conflict of interest The authors reported no conflict of interest.

International audience; AbstractBacteria of the genus Dickeya are phytopathogens characterised by a wide host range and large geographical distribution. The disease is named soft rot because the plant material is liquefied by bacterial enzymes. The massive production of pectate lyases is typical of Dickeya. Secretion by a specialised system named Out enables the export of pectinases that cause soft rot by cleaving pectin present in plant cell walls. The 10 species of the genus Dickeya were isolated from diseased plants or water. They attack a variety of crops and ornamental plants in tropical, subtropical and temperate climates. Dickeya solani and Dickeya dianthicola are the two main species responsible for potato diseases, leading to significant economic losses. Recent diseases on fruit trees are also due to Dickeya. These bacteria have developed different mechanisms to cope with adverse conditions and compete with other microorganisms. In addition, they use a complex regulatory network to adjust the production of pectate lyases during the successive phases of plant infection.Key Concepts Dickeya members are plant pathogens characterised by a broad‐host range and a large geographical distribution. The genus Dickeya is subdivided into ten species, seven acting as phytopathogens and three found in water. Dickeya species are ‘brute force’ pathogens as they use a set of plant cell wall degrading enzymes as their primary weapon. Massive production of pectate lyases and accessory pectinases is the main virulence signature of the Dickeya species; they cause the symptom of rotting of the plant tissues. Since antibiotics are not allowed in agriculture, there is currently no effective chemical control for Dickeya. Dickeya has developed mechanisms to compete with other microorganisms and to cope with stressful conditions found in the environment or during plant colonisation. The infectious process begins with an asymptomatic phase, corresponding to the asymptomatic presence of Dickeya in plant tissues, followed by the symptomatic phase corresponding to soft‐rot appearance. The disease appears when environmental parameters, mainly temperatures and humidity, become favourable. During the plant infection, the expression of pectate lyase genes is finely controlled by a complex regulatory network. Besides pectate lyase secretion, many other functions favour the bacterial virulence, such as protein secretion systems, motility, chemotaxis, iron capture and envelope components.

International audience; Objective: To establish recommendations on pregnancy in women with neuromyelitis optica spectrum disorders (NMOSD).Background: In 2020, the French Multiple Sclerosis (MS) Society (SFSEP) decided to develop a national evidence-based consensus on pregnancy in MS. As NMOSD and MOG-antibody associated disease (MOGAD) share a series of commonalities with MS, and some significant differences about that topic, specific recommendations had to be developed.Design/Methods: The French Group for Recommendations in Multiple Sclerosis (France4MS) reviewed articles from PubMed and universities databases (January 1975 through December 2020). The RAND/UCLA appropriateness method, which was developed to synthesize the scientific literature and expert opinions on health care topics, was used to reach a formal agreement. 58 MS experts worked on the full-text review and initial wording of recommendations. A sub-group of 9 NMOSD experts was dedicated to analyzing of available data on NMOSD and MOGAD. A group of multidisciplinary healthcare specialists validated the final proposal of summarized evidences.Results: A strong agreement was reached for all 66 proposed recommendations. They cover diverse topics, such as pregnancy planning, follow-up during pregnancy and in the post-partum, delivery routes, loco-regional analgesia or anesthesia, prevention of post-partum relapses, breastfeeding, vaccinations, reproductive assistance, management of relapses, and disease-modifying treatments. Details will be presented at the AAN congress.Conclusions: Physicians and patients should be aware of the new evidence-based recommendations of the French MS Society for pregnancy in women with NMOSD and MOGAD.

In November 2017, Biomphalaria pfeifferi, the key intermediate host for Schistosoma mansoni in Africa, was first reported in Lake Malawi, Mangochi District. Two subsequent malacological surveys in 2018 and 2019 confirmed its lacustrine presence, as well as its presence along the Upper Shire River. These surveys provided sufficient specimens for analyses of the genetic structure and a transmission assessment for intestinal schistosomiasis. A total of 76 collected snails were characterized by a DNA sequence analysis of a 650 bp fragment of the mitochondrial cytochrome oxidase subunit 1 (cox1); by size fractionation of six fluorescently labelled microsatellite loci (Bgμl16, Bgμl, Bpf8, rg6, U-7, and rg9);by denaturing PAGE; and by detection of pre-patent Schistosoma infection by real-time PCR with a TaqMan® probe. Five closely related cox1 haplotypes were identified, all present within a single location, with only one haplotype common across all the other locations sampled. No allelic size variation was detected with the microsatellites and all loci were monomorphic. Overall, the pre-patent prevalence of Schistosoma spp. was 31%, with infected snails found at several sampling locations. In this part of Lake Malawi, Bi. pfeifferi exhibits low genetic diversity and is clearly being exposed to the miracidia of S. mansoni, which is likely facilitating the autochthonous transmission of this parasite.

Temporomandibular disorder (TMD) perturbs the tongue motor control and consequently impairs oral function, but strength training reduces this impairment. However, tongue motor control is widely reduced to a matter of strength.To investigate the accuracy of the tongue placement as a measure of tongue motor control in patients with TMD compared with age- and sex-matched healthy participants.This proof-of-concept case-control study was prospective, observational, and part of the TMIQ study (NCT04102306). After pointing against a wood stick while maintaining the tongue as sharp as possible, the examinator drew the contour of the tongue print on the wood stick, which was then scanned for image analyses to compute the area for each participant using ImageJ.A total of 94 participants were included, all patients with TMD (n = 47) diagnosed with myalgia, 61% with intra-articular joint disorder accordingly to the DC/TMD. The median (IQR) tongue print area was 117 (111) mmThe results suggest that TMD impairs the motor control of the tongue. Therefore, the sharpest tongue pointing test may constitute a simple and accessible clinical tool to assess the accuracy of tongue placement in TMD patients. The study was registered on ClinicalTrial.gov with identification number NCT04102306.

The soft rot Pectobacteriaceae (SRP) infect a wide range of plants worldwide and cause economic damage to crops and ornamentals but can also colonize other plants as part of their natural life cycle. They are found in a variety of environmental niches, including water, soil and insects, where they may spread to susceptible plants and cause disease. In this chapter, we look in detail at the plants colonized and infected by these pathogens and at the diseases and symptoms they cause. We also focus on where in the environment these organisms are found and their ability to survive and thrive there. Finally, we present evidence that SRP may assist the colonization of human enteric pathogens on plants, potentially implicating them in aspects of human/animal as well as plant health.

Dickeya are plant pathogenic bacteria able to provoke disease on a wide range of plants. A type 2 secretion system (T2SS) named Out is necessary for bacterial virulence. Its study in D. dadantii showed that it secretes a wide range of plant cell wall degrading enzymes, including pectinases and a cellulase. However, the full repertoire of exoproteins it can secrete has probably not yet been identified. Secreted proteins are first addressed to the periplasm before their secretion by Out. No secretion signal present on the protein allows the identification of substrates of a T2SS. To identify new Out substrates, we analyzed D. dadantii transcriptome data obtained in plant infection condition and searched for genes strongly induced encoding a protein with a signal sequence. We identified four new Out-secreted proteins: the expansin YoaJ, the putative virulence factor VirK and two proteins of the DUF 4879 family, SvfA and SvfB. We showed that SvfA and SvfB are required for full virulence of D. dadantii and showed that svf genes are present in a variable number of copies in other Pectobacteriaceae, up to three in D. fanghzongdai. This work opens the way to the study of the role of non-pectinolytic proteins secreted by the Out pathway in Pectobacteriaceae.IMPORTANCEThe plant pathogen Dickeya rely on a type 2 secretion system named Out for their pathogenicity. Importance of plant cell wall degrading enzymes secreted by this system has been well studied. However, existence and role of other Out-secreted proteins has barely been investigated. By mining D. dadantii transcriptome data, we identified four new Out-secreted proteins. We showed that two of them, SvfA and SvfB, are necessary for the full virulence of the bacteria. These findings show that identification of all the proteins secreted by the Dickeya Out system is necessary for a better knowledge of the virulence of these bacteria.

It has long been the view that the neurons in the brain are responsible for its ability to process information from external cues and adapt accordingly. The key to this is the brain’s ability to change its internal structure in an activity-dependent manner over several timescales. Synapses are the key sites where changes, both structurally ad functionally, such take place. The neurons in the mammalian brain, however, only make up half the number of cells. The remaining cells are collectively called glial cells, a family of cells that are comprised of astrocytes, oligodendrocytes, ependymal cells and radial glia. Historically, these cells were believed to only support the maintenance and wellbeing of neurons, playing no role in information processing, however, over the last twenty years there is mounting evidence illustrating that this is not the case. Currently, experiments have shown that glial cells are directly involved in transmission and modulation of neurotransmitters, synaptic plasticity and have also been implicated in brain disorders, such as epilepsy. To this end, the traditional picture of a synapse being composed of a pre-synaptic terminal, a small extracellular gap and a post-synaptic spine needs revision to include both glial cell and extracellular matrix components. To this end, computational investigations of neural-glial signaling and their impact on synaptic plasticity and spiking neural network dynamics has been sorely lacking. It is the authors’ aspiration that this will inspire future researcher to investigate the complex interactions between neurons and glial cells.

The identification of the virulence factors of plant-pathogenic bacteria has relied on the testing of individual mutants on plants, a time-consuming process. Transposon sequencing (Tn-seq) is a very powerful method for the identification of the genes required for bacterial growth in their host. We used this method in a soft-rot pathogenic bacterium to identify the genes required for the multiplication of Dickeya dadantii in chicory. About 100 genes were identified showing decreased or increased fitness in the plant. Most had no previously attributed role in plant-bacterium interactions. Following our screening, in planta competition assays confirmed that the uridine monophosphate biosynthesis pathway and the purine biosynthesis pathway were essential to the survival of D. dadantii in the plant, as the mutants ∆carA, ∆purF, ∆purL, ∆guaB and ∆pyrE were unable to survive in the plant in contrast with the wild-type (WT) bacterium. This study also demonstrated that the biosynthetic pathways of leucine, cysteine and lysine were essential for bacterial survival in the plant and that RsmC and GcpA were important in the regulation of the infection process, as the mutants ∆rsmC and ∆gcpA were hypervirulent. Finally, our study showed that D. dadantii flagellin was glycosylated and that this modification conferred fitness to the bacterium during plant infection. Assay by this method of the large collections of environmental pathogenic strains now available will allow an easy and rapid identification of new virulence factors.

Few secreted proteins involved in plant infection common to necrotrophic bacteria, fungi and oomycetes have been identified except for plant cell wall-degrading enzymes. Here we study a family of iron-binding proteins that is present in Gram-negative and Gram-positive bacteria, fungi, oomycetes and some animals. Homolog proteins in the phytopathogenic bacterium Dickeya dadantii (IbpS) and the fungal necrotroph Botrytis cinerea (BcIbp) are involved in plant infection. IbpS is secreted, can bind iron and copper, and protects the bacteria against H2O2-induced death. Its 1.7 Å crystal structure reveals a classical Venus Fly trap fold that forms dimers in solution and in the crystal. We propose that secreted Ibp proteins binds exogenous metals and thus limit intracellular metal accumulation and ROS formation in the microorganisms., The authors identify a family of iron-binding proteins that is present in phytopathogenic bacteria, fungi and oomycetes. Some of these proteins are secreted, bind metals, protect the pathogen from H2O2-induced death, and are involved in plant infection.

L'altération qualitative des interactions sociales et de la communication est au premier plan des signes cliniques du Trouble du Spectre de l'Autisme (TSA). L'objectif clinique de l'orthophoniste est d'inciter les patients TSA à devenir des êtres communicants et d'encourager la communication verbale et non verbale. Pour cela, le recours aux outils de communication alternative et augmentative (CAA) de haute technologie est recommandé. Ce mémoire vise à tester l'application IMI, qui se veut novatrice dans ce domaine, auprès de deux enfants TSA non-verbaux et d'évaluer l'impact de son utilisation sur : leur niveau de communication sociale précoce, la fréquence ainsi que la qualité de leurs comportements de communication. L'expérimentation a duré cinq mois pendant lesquels les enfants ont utilisé l'application IMI au sein de l'ULIS TSA dans laquelle ils sont scolarisés 3 à 4 fois par semaine. Les résultats de l'étude montrent que leur niveau de communication social précoce évalué à l'aide de l'Echelle de Communication Sociale Précoce (ECSP) s'améliore avec la mise en place de l'application IMI. Les qualités du regard, de la voix et des gestes et postures ont également évolué positivement au cours de l'expérimentation. Cette évolution se remarque également dans la fréquence d'apparition de certaines situations de communication. Enfin, au cours du temps, le nombre de demandes faites avec l'application IMI a tendance à augmenter. Toutefois le faible nombre de participants à cette étude ne permet pas de généraliser ces résultats à l'ensemble de la population des TSA non-verbaux. Par ailleurs, l'application IMI pourrait être proposée à d'autres populations nécessitant un tel outil.

Two surveys conducted in 2017 and 2018 demonstrated Biomphalaria pfeifferi snails in Lake Malawi in Africa. Epidemiologic examination of 175 local children at 3 primary schools confirmed emergence of intestinal schistosomiasis. These findings highlight autochthonous transmission of Schistosoma mansoni flukes in Lake Malawi and the need to revise international travel advice.

International audience; he identification of the virulence factors of plant‐pathogenic bacteria has relied on the testing of individual mutants on plants, a time‐consuming process. Transposon sequencing (Tn‐seq) is a very powerful method for the identification of the genes required for bacterial growth in their host. We used this method in a soft‐rot pathogenic bacterium to identify the genes required for the multiplication of Dickeya dadantii in chicory. About 100 genes were identified showing decreased or increased fitness in the plant. Most had no previously attributed role in plant–bacterium interactions. Following our screening, in planta competition assays confirmed that the uridine monophosphate biosynthesis pathway and the purine biosynthesis pathway were essential to the survival of D. dadantii in the plant, as the mutants ∆carA, ∆purF, ∆purL, ∆guaB and ∆pyrE were unable to survive in the plant in contrast with the wild‐type (WT) bacterium. This study also demonstrated that the biosynthetic pathways of leucine, cysteine and lysine were essential for bacterial survival in the plant and that RsmC and GcpA were important in the regulation of the infection process, as the mutants ∆rsmC and ∆gcpA were hypervirulent. Finally, our study showed that D. dadantii flagellin was glycosylated and that this modification conferred fitness to the bacterium during plant infection. Assay by this method of the large collections of environmental pathogenic strains now available will allow an easy and rapid identification of new virulence factors.

Soft rot enterobacteria (DickeyaandPectobacterium) are major pathogens that cause diseases on plants of agricultural importance such as potato and ornamentals. Long term studies to identify virulence factors of these bacteria focused mostly on plant cell wall degrading enzymes secreted by the type II secretion system and the regulation of their expression. To identify new virulence factors we performed a Tn-seq genome-wide screen of a transposon mutant library during chicory infection followed by high-throughput sequencing. This allowed the detection of mutants with reduced but also increased fitness in the plant. Virulence factors identified differed from those previously known since diffusible ones (secreted enzymes, siderophores or metabolites) were not detected by this screen. In addition to genes encoding proteins of unknown function that could be new virulence factors, others could be assigned to known biological functions. The central role of the FlhDC regulatory cascade in the control of virulence was highlighted with the identification of new members of this pathway. Scarcity of the plant in certain amino acids and nucleic acids required presence of the corresponding biosynthetic genes in the bacteria. Their products could be targets for the development of antibacterial compounds. Among the genes required for full development in chicory we also identified six genes involved in the glycosylation of the flagellin FliC, glycosylation, which in other plant pathogenic bacteria contributes to virulence.Author summaryIdentification of virulence factors of plant pathogenic bacteria has relied on the test of individual mutants on plants, a time-consuming method. New methods like transcriptomic or proteomic can now be used but they only allow the identification of genes induced during the infection process and non-induced genes may be missed. Tn-seq is a very powerful method to identify genes required for bacterial growth in their host. We used for the first time this method in a plant pathogenic bacteria to identify genes required for the multiplication ofDickeya dadantiiin chicory. We identified about 100 genes with decreased or increased fitness in the plant. Most of them had no previously described role in bacterial virulence. We unveiled important metabolic genes and regulators of motility and virulence. We showed thatD. dadantiiflagellin is glycosylated and that this modification confers fitness to the bacteria during plant infection. Our work opens the way to the use of Tn-seq with bacterial phytopathogens. Assay by this method of large collections of environmental pathogenic strains now available will allow an easy and rapid identification of new virulence factors.

International audience; The interactions between viruses and actin cytoskeleton have been widely studied. We showed that rotaviruses remodel microfilaments in intestinal cells and demonstrated that this was due to the VP4 spike protein. Microfilaments mainly occur in the apical domain of infected polarized enterocytes and favor the polarized apical exit of viral progeny. The present work aims at the identification of molecular determinants of actin-VP4 interactions. We used various deletion mutants of VP4 that were transfected into Cos-7 cells and analyzed interactions by immunofluorescence confocal microscopy. It has been established that the C-terminal part of VP4 is embedded within viral particles when rotavirus assembles. The use of specific monoclonal antibodies demonstrated that VP4 is expressed in different forms in infected cells: classically as spike on the outer layer of virus particles, but also as free soluble protein in the cytosol. The C terminus of free VP4 was identified as interacting with actin microfilaments. The VP4 actin binding domain is unable to promote microfilament remodeling by itself; the coiled-coil domain is also required in this process. This actin-binding domain was shown to dominate a previously identified peroxisomal targeting signal, located in the three last amino acids of VP4. The newly identified actin-binding domain is highly conserved in rotavirus strains from species A, B, and C, suggesting that actin binding and remodeling is a general strategy for rotavirus exit. This provides a novel mechanism of protein-protein interactions, not involving cell signaling pathways, to facilitate rotavirus exit. IMPORTANCE Rotaviruses are causal agents of acute infantile viral diarrhea. In intestinal cells, in vitro as well as in vivo, virus assembly and exit do not imply cell lysis but rely on an active process in which the cytoskeleton plays a major role. We describe here a novel molecular mechanism by which the rotavirus spike protein VP4 drives actin remodeling. This relies on the fact that VP4 occurs in different forms. Besides its structural function within the virion, a large proportion of VP4 is expressed as free protein. Here, we show that free VP4 possesses a functional actin-binding domain. This domain, in coordination with a coiled-coil domain, promotes actin cytoskeleton remodeling, thereby providing the capacity to destabilize the cell membrane and allow efficient rotavirus exit.

O-polysaccharides were isolated from lipopolysaccharides obtained from four different strains of plant pathogenic bacteria belonging to the species Dickeya solani : two of them were isolated in Poland (IFB0099 and IFB0158), the third in Germany (IFB0223) and the last one, D. solani Type Strain IPO2222, originated from the Netherlands. In addition, the O-polysaccharide of a closely related species D. dadantii strain 3937 was isolated. The purified polysaccharides of the five strains were analyzed using NMR spectroscopy and chemical methods. Sugar and methylation analyses, including absolute configuration assignment, together with NMR data revealed that all O-polysaccharides tested are homopolymers of 6-deoxy- d -altrose ( d -6dAlt) the following structure: →2)-β- d -6dAlt p -(1→

Les éleveurs ovins laitiers sont de plus en plus préoccupés par les diarrhées néonatales des agneaux, qui occasionnent des pertes économiques importantes. L’objectif principal de cette étude était de mieux décrire les circonstances d’apparition des diarrhées ainsi que certains facteurs de risque liés aux agneaux et aux brebis, au microbisme, au logement et à la conduite d’élevage dans 20 élevages des Pyrénées Atlantiques suivis pendant un mois lors des agnelages du premier lot de reproduction. Dans la majorité des élevages suivis, les diarrhées sont apparues dès la première semaine d’agnelages avec une morbidité n’excédant pas 25% et une mortalité toujours inférieure à 8%. Cryptosporidium parvum a été fréquemment retrouvé mais dans la majorité des prélèvements effectués, aucun agent pathogène n’a été identifié. Les résultats indiquent par ailleurs que les défauts de transfert d’immunité passive sont fréquents et que le statut parasitaire défavorable des brebis, leur état corporel insuffisant à l’agnelage, et la composition du lait dans la phase d’allaitement pourraient être impliqués dans les troubles de santé. L’ensemble de ces résultats, obtenus sur un faible effectif d’élevages, mérite d’être confirmé sur un échantillon plus large.

This paper presents a fully autonomous integrated circuit (IC) dedicated to piezoelectric harvesters. The novel Multi-Shot Synchronous Electric Charge Extraction (MS-SECE) performed by the IC optimizes the energy transfer from a highly charged piezoelectric harvester to a low voltage storage element. The system deals with piezoelectric powers in the 10 µW to 1 mW range and handles very high piezoelectric voltage values ( $>$ 100 V) thanks to the off-chip components around the IC. The IC has been fabricated in AMS 0.35 µm 3.3 V technology and its low power consumption (1 µW @ 5 Hz) is particularly suitable for low frequency harvesters. MS-SECE increases the extracted power compared to the Maximum Power Point Tracking (MPPT) technique but it also improves the efficiency by up to 25% compared to standard SECE. Furthermore, MS-SECE allows the use of small off-chip components: an efficiency of 61% has been reached with a 125 mm 3 coupled-inductor. Finally, the proposed power management circuit self-starts, works without any battery and its overall volume is expected to be less than 1 cm 3 .

Pectate lyases are enzymes involved in plant cell wall degradation. They cleave pectin using a β-elimination mechanism, specific for acidic polysaccharides. They are mainly produced by plant pathogens and plant-associated organisms, and only rarely by animals. Pectate lyases are also commonly produced in the bacterial world, either by bacteria living in close proximity with plants or by gut bacteria that find plant material in the digestive tract of their hosts. The role of pectate lyases is essential for plant pathogens, such as Dickeya dadantii, that use a set of pectate lyases as their main virulence factor. Symbiotic bacteria produce their own pectate lyases, but they also induce plant pectate lyases to initiate the symbiosis. Pectin degradation products may act as signals affecting the plant–bacteria interactions. Bacterial pectate lyases are also essential for using the pectin of dead or living plants as a carbon source for growth. In the animal gut, Bacteroides pectate lyases degrade the pectin of ingested food, and this is particularly important for herbivores that depend on their microflora for the digestion of pectin. Some human pathogens, such as Yersinia enterocolitica, produce a few intracellular pectate lyases that can facilitate their growth in the presence of highly pectinolytic bacteria, at the plant surface, in the soil or in the animal gut.

This paper presents a simulation study dealing with the influence of different factors on the energy consumption of an electric vehicle (EV). Due to the limited quantity of energy embedded in the battery, EVs are very sensitive to parameters which can influence their energy consumption and then can induce huge variations in their actual range. Among all these factors, driving conditions, auxiliaries' impact, driver's aggressiveness and braking energy recovery strategy are to be considered as the main factors influencing the EV energy consumption. The objective of this paper is thus to simulate and quantify the influence of each factor independently. For this, a virtual EV simulator has been created and validated through EVs experiments on a climatic 4WD chassis dyno in the frame of a project sponsored by the French ADEME and with the help of PSA, Renault and Tazzari car manufacturers. This simulator, validated thanks to a limited number of experimental results, has been then used on a very large range of operating conditions and hypotheses to extrapolate experimental results and help the analyses of influencing factors.

Environmental Risk Assessments (ERA) have been extensively carried out in 2014 by the Company (TOTAL) as part of the Technological Risk Assessment process. In that context it has been applied to nearshore Gabon pipelines and loading terminal located in the vicinity of Mandji Island and Cap Lopez. The approach used is consistent with the methodology already applied to far off-shore installations but in this case was applied for the first time to installations located at a few kilometers from the coast and using a validated set of hindcast current and wind data developed purposely for west coast Africa. The methodology applied takes into account the trajectory of potential oil spills and the probabilities that oil reaches any environmental resources. The tools used are 3D oil drift model (OSCAR) and exposure effect relations coming from the MIRA method developed in Norway. Four oil spill scenarios have been selected as representing most of oil spill cases requiring detailed environmental risk assessment on the basis of the technological risk assessment done on these installations. For each spill scenario, oil drift simulations were conducted in stochastic mode on the basis of 10 years historical wind and current data with 3km resolution. Quantities of oil and associated probabilities of presence were calculated for each cell of the model and comparison could be made with Argos drifter experiments in the case of one scenario. Shoreline habitats, turtles nesting beaches, seabirds, fisheries and mangroves have been selected as the key environmental resources to consider in this study. The results have been used to position the scenarios on the company risk matrix, assess environmental risk and address further needs on risk reduction measures. Results are discussed with some emphasis on the dominating role of current pattern in the area showing that environmental resources at risk are sometimes not the closest to the spill location. Validation aspects of the methodology related to current and Argos drifter experiment data are also discussed.

Modification of teichoic acid through the incorporation of d -alanine confers resistance in Gram-positive bacteria to antimicrobial peptides (AMPs). This process involves the products of the dltXABCD genes. These genes are widespread in Gram-positive bacteria, and they are also found in a few Gram-negative bacteria. Notably, these genes are present in all soft-rot enterobacteria ( Pectobacterium and Dickeya ) whose dltDXBAC operons have been sequenced. We studied the function and regulation of these genes in Dickeya dadantii . dltB expression was induced in the presence of the AMP polymyxin. It was not regulated by PhoP, which controls the expression of some genes involved in AMP resistance, but was regulated by ArcA, which has been identified as an activator of genes involved in AMP resistance. However, arcA was not the regulator responsible for polymyxin induction of these genes in this bacterium, which underlines the complexity of the mechanisms controlling AMP resistance in D. dadantii . Two other genes involved in resistance to AMPs have also been characterized, phoS and phoH . dltB , phoS , phoH , and arcA but not dltD mutants were more sensitive to polymyxin than the wild-type strain. Decreased fitness of the dltB , phoS , and phoH mutants in chicory leaves indicates that their products are important for resistance to plant AMPs. IMPORTANCE Gram-negative bacteria can modify their lipopolysaccharides (LPSs) to resist antimicrobial peptides (AMPs). Soft-rot enterobacteria ( Dickeya and Pectobacterium spp.) possess homologues of the dlt genes in their genomes which, in Gram-positive bacteria, are involved in resistance to AMPs. In this study, we show that these genes confer resistance to AMPs, probably by modifying LPSs, and that they are required for the fitness of the bacteria during plant infection. Two other new genes involved in resistance were also analyzed. These results show that bacterial resistance to AMPs can occur in bacteria through many different mechanisms that need to be characterized.

Monitoring of electrocorticography signals using multi-electrode array creates new opportunities for neural prosthetic applications. In this paper, we present a 32-channel recording ASIC that provides low-noise amplification and analog filtering. It also includes a 12-bit analog-to-digital conversion function, and offers programmable output rates through a serial peripheralinterface (SPI). The targeted application is a remote-powered wireless implantable ECoG recording system. Each recording channel has a measured 0.7 $\mu {\rm V_{\rm rms}}$ input-referred noise on a [0.5–300 Hz] bandwidth. The device was fabricated in a 0.35 $\mu{\rm m}$ complementary metal–oxide–semiconductor process for a total die area of 86 ${\hbox {mm}} ^{2}$ with an analog power consumption limited to 134 $\mu {\rm W}$ per channel.

Asynchronous circuits are well-suited to ultra-low-power design. This article presents a microsystem that is powered only by energy extracted from the environment to implement an autonomous sensing application. Key to this application is the use of asynchronous logic, which not only provides greater energy efficiency due to its event-driven nature but, more importantly, allows graceful adaptation to highly variable power availability.

RésuméObjectifLa gestion de l’ostéoporose du blessé médullaire est une question récurrente dans la pratique quotidienne, mais la revue de la littérature ne fournit pas de protocole standardisé ni pour le dépistage, ni pour une stratégie de prévention ou de traitement. Nous avons évalué les pratiques des médecins de médecine physique et de réadaptation en France, avec comme objectif final de faire une proposition de prise en charge préventive et curative de cette ostéoporose.MéthodeUn questionnaire a été envoyé à des praticiens exerçant une activité auprès de blessés médullaires en séjour en centre et en suivi. Le questionnaire comportait majoritairement des questions fermées.RésultatsVingt-six questionnaires ont été analysés. Le dépistage de l’ostéoporose n’est effectué de façon systématique que pour 19,2 % des médecins et après une fracture dans 80,2 % des cas. Le diagnostic de l’ostéoporose repose sur l’ostéodensitométrie (96 %). La verticalisation reste un moyen de prévention pour 88 % des médecins à la phase aiguë et pour 77 % à la phase chronique. Quatre-vingt-douze pour cent des praticiens traitent au stade d’ostéoporose confirmée.ConclusionIl n’y a globalement pas de prise en charge standardisée de l’ostéoporose chez le blessé médullaire. La recherche en est faite le plus souvent après fracture. Les données de la littérature et les résultats de ce questionnaire nous ont amenés à proposer un protocole de diagnostic précoce et de traitement préventif de l’ostéoporose à la phase aiguë, puis une surveillance systématique de la densité minérale osseuse.AbstractObjectiveThe management of osteoporosis in spinal cord injury that is a recurring issue in daily practice, but unfortunately, no standard protocol is provided by the literature review, either for screening or for a strategy of prevention and even for therapy. We assessed the practices of the physicians in physical medicine and rehabilitation from all over France, with the ultimate aim to propose a consensus for preventive and curative cares of that osteoporosis.MethodsA questionnaire was sent to practitioners engaged with spinal cord injury (SCI) patients residing in the center and patients in medical monitoring. The questionnaire consisted mainly of closed questions.ResultsTwenty-six questionnaires are analyzed. The screening for osteoporosis is made routinely by only 19.2% of the practitioners and after a fracture in only 80.2% of the cases. The diagnosis of osteoporosis is based on bone densitometry (DEXA) (96%). Standing still remains a means of prevention for 88% of physicians in the acute phase and for 77% in the chronic phase. Ninety-two percent of practitioners treat at the stage of established osteoporosis.ConclusionThere is generally no standardized management of osteoporosis in practice for SCI patients. The searching for osteoporosis is usually performed after a fracture. All the literature data and results of the questionnaire led us to propose a protocol consisting in a systematic monitoring of the bone mineral density for the screening of osteoporosis, but also a procedure for early diagnosis and for preventive treatment of osteoporosis in the acute phase.

The plant pathogenic bacteria Dickeya dadantii is also a pathogen of the pea aphid Acyrthosiphon pisum. The genome of the bacteria contains four cyt genes, encoding homologues of Bacillus thuringiensis Cyt toxins, which are involved in its pathogenicity to insects. We show here that these genes are transcribed as an operon, and we determined the conditions necessary for their expression. Their expression is induced at high temperature and at an osmolarity equivalent to that found in the plant phloem sap. The regulators of cyt genes have also been identified: their expression is repressed by H-NS and VfmE and activated by PecS. These genes are already known to regulate plant virulence factors, but in an opposite way. When tested in a virulence assay by ingestion, the pecS mutant was almost non-pathogenic while hns and vfmE mutants behaved in the same way as the wild-type strain. Mutants of other regulators of plant virulence, GacA, OmpR and PhoP, that do not control Cyt toxin production, also showed reduced pathogenicity. In an assay by injection of bacteria, the gacA strain was less pathogenic but, surprisingly, the pecS mutant was slightly more virulent. These results show that Cyt toxins are not the only virulence factors required to kill aphids, and that these factors act at different stages of the infection. Moreover, their production is controlled by general virulence regulators known for their role in plant virulence. This integration could indicate that virulence towards insects is a normal mode of life for D. dadantii.

Sialic acids are acidic sugars present mostly on vertebrate cell surfaces, which can be metabolized by bacteria and act as an inflammation signal. N-Acetylneuraminic acid, the most abundant sialic acid, can enter into Escherichia coli K12 through NanC, an N-acetylneuraminic acid-inducible outer-membrane channel. With its 215 residues, NanC belongs to the family of small monomeric KdgM-related porins. KdgM homologues are found in gammaproteobacteria, including major plant and human pathogens, and together they define a large family of putative acidic sugar/oligosaccharide transporters, which are as yet poorly characterized. Here, we present the first high-resolution structure of a KdgM family member. NanC folds into a 28-A-high, 12-stranded beta-barrel, resembling the beta-domain of autotransporter NalP and defining an open pore with an average radius of 3.3 A. The channel is lined by two strings of basic residues facing each other across the pore, a feature that appears largely conserved within the KdgM family and is likely to facilitate the diffusion of acidic oligosaccharides.

Resume Introduction La medecine physique et de readaptation (MPR) nous amene a prendre en charge des patients atteints d’un cancer necessitant de la reeducation pour des deficiences associees. Le caractere evolutif de la maladie implique alors des projets reeducatifs differents de ceux concus lors des pathologies habituellement prises en charge en MPR. Objectif Reflechir sur cet aspect de la MPR au travers des situations vecues. Methode Analyse des cas avec reflexion sur des situations de patients admis en MPR au CHU pour reeducation neurologique et presentant un cancer, connu ou decouvert. Resultats Vingt-quatre cas cliniques repertories (1998–2006) : quatre cas presentes du fait des divers problemes rencontres ; le contexte cancereux n’a pas influence le cours du sejour en MPR dans sept cas seulement. Discussion et conclusion L’accompagnement des patients atteints d’une maladie de mauvais pronostic vital differe de la demarche reeducative et pose des problemes therapeutiques et relationnels inhabituels en MPR. Les reponses face a la mort ne sont pas les memes qu’en situation de handicap. Les acteurs de reeducation s’interrogent sur leur role lorsque la fonctionnalite est au second plan. La reponse a la douleur physique comporte une approche souvent comportementale en reeducation, necessitant alors l’adhesion du patient aux programmes reeducatifs. En cancerologie, cette approche comportementale n’est pas au premier plan et le traitement de la douleur reste medicamenteux avant tout. L’accompagnement de ces patients necessite des liens etroits avec les services de cancerologie. Il est, en outre, necessaire d’aborder differemment la reeducation, de ne jamais oublier l’evolutivite du cancer pouvant « retourner » des situations fonctionnelles ou pronostiques et d’etre entoure d’un personnel prepare a cela.

An autonomous power generator unit including two micropower sources and their management IC has been fabricated: a RF power receiver and a 1 V miniature thermogenerator combined with a micropower DC/DC up-converter are combined with a 78% efficiency manager and charger, and a 5 nW discharge monitor to manage and store the harvested energy in a 30 above-IC deposited microbattery.

We present the projection structures of the three outer membrane porins KdgM and KdgN from Erwinia chrysanthemi and NanC from Escherichia coli, based on 2D electron crystallography. A wide screening of 2D crystallization conditions yielded tubular crystals of a suitable size and quality to perform high-resolution electron microscopy. Data processing of untilted samples allowed us to separate the information of the two crystalline layers and resulted in projection maps to a resolution of up to 7A. All three proteins exhibit a similar putative beta-barrel structure and the three crystal forms have the same symmetry. However, there are differences in the packing arrangements of the monomers as well as the densities of the projections. To interpret these projections, secondary structure prediction was performed using beta-barrel specific prediction algorithms. The predicted transmembrane beta-barrels have a high similarity in the arrangement of the putative beta-strands and the loops, but do not match those of OmpG, a related protein porin whose structure was solved.

The promyelocytic leukemia (PML) tumour suppressor is the organiser of PML nuclear bodies, which are domains the precise functions of which are still disputed. We show that upon several types of stress, endogenous PML proteins form nucleolar caps and eventually engulf nucleolar components. Only two specific PML splice variants (PML-I and PML-IV) are efficiently targeted to the nucleolus and the abundant PML-I isoform is required for the targeting of endogenous PML proteins to this organelle. We identified a nucleolar targeting domain within the evolutionarily conserved C-terminus of PML-I. This domain contains a predicted exonuclease III fold essential for the targeting of the PML-I C-terminus to nucleolar fibrillar centres. Furthermore, spontaneous or oncogene retrieval-induced senescence is associated with the formation of very large PML nuclear bodies that initially contain nucleolar components. Later, poly-ubiquitin conjugates are found on the outer shell or within most of these senescence-associated PML bodies. Thus, unexpectedly, the scarcely studied PML-I isoform links PML bodies, nucleolus, senescence and proteolysis.

The entry of oligogalacturonates into Dickeya dadantii occurs through the specific channel KdgM. The genome of the bacterium encodes a second member of this family of outer membrane proteins, KdgN. We showed that this protein is also involved in the uptake of oligogalacturonates. When KdgN was reconstituted in proteoliposomes, it formed channels with a conductance of about 450 pS at a positive potential. These channels had weak anionic selectivity. The regulation of kdgN is complex, and five genes controlling the expression of kdgN have been identified: kdgR , pecS , ompR , hns , and crp . Moreover, kdgN was regulated by growth phase but only when bacteria were grown in rich medium. Most of these regulators of kdgN also control kdgM expression, but some of them regulate kdgM in the opposite manner: while PecS and OmpR are repressors of kdgM , they are activators of kdgN . This pattern resembles the regulation of the Escherichia coli general porins OmpF and OmpC, but such opposite regulation of two specific outer membrane channels has never been described before. KdgN may allow the bacteria to collect oligogalacturonates under saprophytic conditions, when virulence genes, including kdgM , are not expressed.

Following elucidation of the regulation of the lactose operon in Escherichia coli , studies on the metabolism of many sugars were initiated in the early 1960s. The catabolic pathways of D-gluconate and of the two hexuronates, D-glucuronate and D-galacturonate, were investigated. The post genomic era has renewed interest in the study of these sugar acids and allowed the complete characterization of the D-gluconate pathway and the discovery of the catabolic pathways for L-idonate, D-glucarate, galactarate, and ketogluconates. Among the various sugar acids that are utilized as sole carbon and energy sources to support growth of E. coli , galacturonate, glucuronate, and gluconate were shown to play an important role in the colonization of the mammalian large intestine. In the case of sugar acid degradation, the regulators often mediate negative control and are inactivated by interaction with a specific inducer, which is either the substrate or an intermediate of the catabolism. These regulators coordinate the synthesis of all the proteins involved in the same pathway and, in some cases, exert crosspathway control between related catabolic pathways. This is particularly well illustrated in the case of hexuronide and hexuronate catabolism. The structural genes encoding the different steps of hexuronate catabolism were identified by analysis of numerous mutants affected for growth with galacturonate or glucuronate. E. coli is able to use the diacid sugars D-glucarate and galactarate (an achiral compound) as sole carbon source for growth. Pyruvate and 2-phosphoglycerate are the final products of the D-glucarate/galactarate catabolism.

Reducing fuel consumption and thus greenhouse gas emissions is a major challenge for the automotive industry. To help achieve this goal, Diesel combustion engines as well as hybrid architectures are often used to further improve vehicle fuel efficiency. Combining these two technologies, the Peugeot 3008 Hybrid 4 was the first production vehicle utilizing a Diesel engine in a full hybrid powertrain with significant electric operating capability. This paper briefly introduces this vehicle's hybrid topology and provides analysis regarding vehicle fuel consumption and operation over a large panel of drive cycles as well as hot (35°C) and cold (−7°C) ambient conditions.

International audience; In the track of new biopesticides, four genes namely cytA, cytB, cytC and cytD encoding proteins homologous to Bacillus thuringiensis (Bt) Cyt toxins have been identified in the plant pathogenic bacteria Dickeya dadantii genome. Here we show that three Cyt-like d-endotoxins from D. dadantii (CytA, CytB and CytC) are toxic to the pathogen of the pea aphid Acyrthosiphon pisum in terms of both mortality and growth rate. The phylogenetic analysis of the comprehensive set of Cyt toxins available in genomic databases shows that the whole family is of limited taxonomic occurrence, though in quite diverse microbial taxa. From a structure-function perspective the 3D structure of CytC and its backbone dynamics in solution have been determined by NMR. CytC adopts a cytolysin fold, structurally classified as a Cyt2-like protein. Moreover, the identification of a putative lipid binding pocket in CytC structure, which has been probably maintained in most members of the Cyt-toxin family, could support the importance of this lipid binding cavity for the mechanism of action of the whole family. This integrative approach provided significant insights into the evolutionary and functional history of D. dadantii Cyt toxins, which appears to be interesting leads for biopesticides. W eeds, pathogens and animal pests are potentially responsible for huge economic losses in agricultural production, and about 20% of these losses are due to animal pests 1. Among insects, aphids (Hemiptera: Aphidoidea) are one of the most injuring taxa for agricultural plants. They are difficult to control due to their specialized feeding mechanism and unusual reproductive biology 2,3. As a result, the management of aphid populations is quite challenging. Until now, most aphid pest control strategies rely on the use of specific sets of systemic chemical pesticides. But the extensive use of these pesticides had led to resistance to insecticides in several aphid species 4,5 , and cause significant environmental damage by targeting different guilds of beneficial insects (predators, parasitoids, and pollinators) 6,7. Therefore, it is highly desirable to develop biopesticides with low non-target effects. A substitute to current chemical pesticides is plant bioengineering; in order to be more selective to target pests, plants can be genetically modified to express insecticidal biomolecules within specific tissues 8. Nevertheless, as happened with conventional pesticides, plant bioengineering has also led to some field insect resistance 9. Hence, crops with more than one defensive protein, each with a different mechanism of action, have been proposed to delay insect resistance (gene pyramiding). However, very few genetically modified plants have yet been developed with resistance to sap-sucking insects, and none is used commercially 10–12. Therefore it seems essential to further develop suitable biopesticides, which could turn into candidate genes for the development of aphid-tolerant plants. In the track of such biopesticides, bacterial toxins did provide paradigmatic solutions, such as the crystal toxins encoded in plasmids of the soil bacterium Bacillus thuringiensis (Bt), which provided a vast diversity of Cry-like toxins for plant protection. Recently however, Bt-related toxins were found in genomes outside its original Gram1 bacterium: four genes namely cytA, cytB, cytC and cytD, encoding proteins homologous to Bacillus thuringiensis (Bt) Cyt toxins have been identified in the Dickeya dadantii (formerly Erwinia chrysanthemi) genome 13

Pectate lyases are enzymes involved in plant cell wall degradation. They cleave pectin using a β-elimination mechanism, specific for acidic polysaccharides. They are mainly produced by plant pathogens and plant-associated organisms, and only rarely by animals. Pectate lyases are also commonly produced in the bacterial world, either by bacteria living in close proximity with plants or by gut bacteria that find plant material in the digestive tract of their hosts. The role of pectate lyases is essential for plant pathogens, such as Dickeya dadantii, that use a set of pectate lyases as their main virulence factor. Symbiotic bacteria produce their own pectate lyases, but they also induce plant pectate lyases to initiate the symbiosis. Pectin degradation products may act as signals affecting the plant–bacteria interactions. Bacterial pectate lyases are also essential for using the pectin of dead or living plants as a carbon source for growth. In the animal gut, Bacteroides pectate lyases degrade the pectin of ingested food, and this is particularly important for herbivores that depend on their microflora for the digestion of pectin. Some human pathogens, such as Yersinia enterocolitica, produce a few intracellular pectate lyases that can facilitate their growth in the presence of highly pectinolytic bacteria, at the plant surface, in the soil or in the animal gut.