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International audience; Poly(ornithine-co-citrulline)s are ureido-based polymers which were shown to exhibit tunable upper critical solution temperature (UCST) behavior, a property that can be exploited to develop thermoresponsive nanoparticles for controlled drug delivery systems. To gain insight into the driving forces that govern the formation and dissolution processes of poly(ornithine-co-citrulline) nanoparticles, a molecular dynamics (MD) simulation study has been carried out using MARTINI-based protein coarse-grained models. Multi-microsecond simulations at temperatures ranging from 280 to 370 K show that the fully reparametrized version 3.0 of MARTINI force field is able to capture the dependence on temperature of poly(ornithine-co-citrulline) aggregation and 1 dissolution, while version 2.2 could not account for it. Furthermore, the phase separation observed in these simulations allowed to extrapolate a phase diagram based on the Flory-Huggins theory of polymer solution which could help in future rational design of drug delivery nanoparticles based on poly(amino acid)s.

Recent advances in structural biophysics and integrative modelling methods now allow us to decipher the structures of large macromolecular assemblies. Understanding the dynamics and mechanisms involved in their biological function requires rigorous integration of all available data. We have developed a complete modelling pipeline that includes analyses to extract biologically significant information by consistently combining automated and interactive human-guided steps. We illustrate this idea with two examples. First, we describe the ryanodine receptor, an ion channel that controls ion flux across the cell membrane through transitions between open and closed states. The conformational changes associated with the transitions are small compared to the considerable system size of the receptor; it is challenging to consistently track these states with the available cryo-EM structures. The second example involves homologous recombination, in which long filaments of a recombinase protein and DNA catalyse the exchange of homologous DNA strands to reliably repair DNA double-strand breaks. The nucleoprotein filament reaction intermediates in this process are short-lived and heterogeneous, making their structures particularly elusive. The pipeline we describe, which incorporates experimental and theoretical knowledge combined with state-of-the-art interactive and immersive modelling tools, can help overcome these challenges. In both examples, we point to new insights into biological processes that arise from such interdisciplinary approaches.

International audience

The tribo-assisted technique is a method recently developed to deposit a thin film of a lubricant material on a surface of varied geometry. This technique uses a wiper to deposit, in a tribological contact whose physicochemical conditions are favorable, the lubricant material on the surface to be treated. The deposit can be made in dry or in the presence of liquidTo improve the performances (durability, transferability, mechanical resistance ...) of the films deposited by this technique, we investigated on the morphology and the architecture of a lubricant films of MOS2 and hBN deposited in the presence of the dodecane.This study was carried out in the static contact at the end of the deposit in order to eliminate the liquid film entrained in the contact during the friction.Mapping of the contact area in dodecane thickness using in situ fluorescence spectrometry are carried out and they highlight the presence or no of liquid in the static contact. These analyzes are carried out for load values supported by the contact of 10 N, 5 N, 2 N and 0.5 N in order to evaluate the compactness and rigidity of the films in the applied load range.This microstructural study carried out on the films at the end of the deposit reveals that those formed of MoS2 nanoparticles are compact and have a very smooth surface resulting from the packing of particles in the form of small lamellae; which gives them a good tribological performance, whereas those formed of h-BN nanoparticles are porous and have a rough surface resulting from the stacking of more rigid particles.

International audience; Friction and wear are the first causes of the decrease of the performances and the durability in mechanical systems. The role of lubrication is to minimize friction between the sliding surfaces to protect them from wear. Conventional liquid lubricants are constituted of a base oil and solid additives particles presenting specific properties, such as friction reduction and antiwear performances. The role of friction reducers is to ensure the lubricating performances in boundary lubrication regime. Commercial lubricants generally use graphite and petroleum-based oils because of their recognized lubricating properties, their stability and low cost. However, such lubricants induce health and environmental hazards due to their life cycle.The aim of this work is to investigate the possibility to use local biomass in order to produce environmentally-friendly lubricants. Local vegetable oils are interesting candidates because of their inherent qualities like renewability, bio-degradability, non-toxicity. This work shows that such natural oils present better friction performances than petroleum-based ones. Then considering friction reduction additives, the tribological behaviour of activated carbons synthetized from biomass is evaluated and special attention is paid to the role of the carbon structure, in terms of morphology, size, porosity of the carbon particles on the friction properties of the additives. The tested activated carbons are obtained from either terrestrial (sugar cane bagasse, banana tree, etc.) or alga (sargassum alga) precursors. Very good friction performances are observed by selecting the adequate precursor and tunning the activation experimental conditions. Finally, the determination of the tribological properties of activated carbons/natural oils mixtures results in the first formulation step of our lubricant made from local biomass.

International audience; Friction and wear phenomena are the main causes of the decrease in performances and durability of mechanical systems. The use of tribology, defined as the science that studies the phenomena of friction, wear and lubrication, is essential and constitutes an important economic issue. It is the role of lubrication to minimize friction and protect surfaces from wear. The strategy used to reduce these phenomena is to introduce a lubricant between the sliding surfaces. This lubricant can be solid, liquid or gaseous, and must prevent direct contact between surfaces, with specific properties such as friction reduction, anti-oxidizing or antiwear action. Pure lubricating bases (mineral or synthetic oil) cannot provide all protective functions, so that additives are added to improve their reducing properties of friction and wear. New lubrication strategies use dispersed nanoparticles in lubricants. The approach is to supply the sliding contact with solid particles, which can instantly form a protected low shearing tribological film. This work focuses on the synthesis of new friction reducer additives from local biomass, in order to produce ecofriendly lubricants. These new carbon phases are obtained using the spray-pyrolysis technique [1] with sugarcane from local biomass. It consists in nebulizing a solution of saccharose in the form of micro-droplets, transported to a tubular oven heated at temperatures ranging from 800°C to 1000°C, in order to obtain carbon nanospheres. The first results have permitted to evidence the effects of synthesis conditions (oven temperature, catalyst concentration and carrier gas pressure), on the nanoparticles morphology, using scanning electron microscopy. Raman spectroscopy gives us information about the graphitization degree of the carbon phase .The effect of an annealing process on these particles is studied in order to improve the nanospheres tribological properties

International audience; At present, our molecular knowledge of dystrophin, the protein encoded by the DMD gene and mutated in myopathy patients, remains limited. To get around the absence of its atomic structure, we have developed an innovative interactive docking method based on the BioSpring software in combination with Small-angle X-ray Scattering (SAXS) data. BioSpring allows interactive handling of biological macromolecules thanks to an augmented Elastic Network Model (aENM) that combines the spring network with non-bonded terms between atoms or pseudo-atoms. This approach can be used for building molecular assemblies even on a desktop or a laptop computer thanks to code optimizations including parallel computing and GPU programming. By combining atomistic and coarse-grained models, the approach significantly simplifies the set-up of multi-scale scenarios. BioSpring is remarkably efficient for the preparation of numeric simulations or for the design of biomolecular models integrating qualitative experimental data restraints. The combination of this program and SAXS allowed us to propose the first high-resolution models of the filamentous central domain of dystrophin, covering repeats 11 to 17. Low-resolution interactive docking experiments driven by a potential grid enabled us to propose how dystrophin may associate with F-actin and nNOS. This information provides an insight into medically relevant discoveries to come.

International audience; The evolutionarily conserved Escherichia coli translesion DNA polymerase IV (DinB) is one of three enzymes that can bypass potentially deadly DNA lesions on the template strand during DNA replication. Remarkably, however, DinB is the only known translesion DNA polymerase active in RecA-mediated strand exchange during error-prone double-strand break repair. In this process, a single-stranded DNA (ssDNA)–RecA nucleoprotein filament invades homologous dsDNA, pairing the ssDNA with the complementary strand in the dsDNA. When exchange reaches the 3′ end of the ssDNA, a DNA polymerase can add nucleotides onto the end, using one strand of dsDNA as a template and displacing the other. It is unknown what makes DinB uniquely capable of participating in this reaction. To explore this topic, we performed molecular modeling of DinB's interactions with the RecA filament during strand exchange, identifying key contacts made with residues in the DinB fingers domain. These residues are highly conserved in DinB, but not in other translesion DNA polymerases. Using a novel FRET-based assay, we found that DinB variants with mutations in these conserved residues are less effective at stabilizing RecA-mediated strand exchange than native DinB. Furthermore, these variants are specifically deficient in strand displacement in the absence of RecA filament. We propose that the amino acid patch of highly conserved residues in DinB-like proteins provides a mechanistic explanation for DinB's function in strand exchange and improves our understanding of recombination by providing evidence that RecA plays a role in facilitating DinB's activity during strand exchange.

International audience; Dystrophin, encoded by the DMD gene, is critical for maintaining plasma membrane integrity during muscle contraction events. Mutations in the DMD gene disrupting the reading frame prevent dystrophin production and result in severe Duchenne muscular dystrophy (DMD); in-frame internal deletions allow production of partly functional internally deleted dystrophin and result in less severe Becker muscular dystrophy (BMD). Many known BMD deletions occur in dystrophin's central domain, generally considered to be a monotonous rod-shaped domain based on the knowledge of spectrin family proteins. However, the effects caused by these deletions, ranging from asymptomatic to severe BMD, argue against the central domain serving only as a featureless scaffold. We undertook structural studies combining small-angle X-ray scattering and molecular modeling in an effort to uncover the structure of the central domain, as dystrophin has been refractory to characterization. We show that this domain appears to be a tortuous and complex filament that is profoundly disorganized by the most severe BMD deletion (loss of exons 45–47). Despite the preservation of large parts of the binding site for neuronal nitric oxide synthase (nNOS) in this deletion, computational approaches failed to recreate the association of dystrophin with nNOS. This observation is in agreement with a strong decrease of nNOS immunolocalization in muscle biopsies, a parameter related to the severity of BMD phenotypes. The structural description of the whole dystrophin central domain we present here is a first necessary step to improve the design of microdystrophin constructs toward the goal of a successful gene therapy for DMD

International audience; Ciliates represent a diversified group of protists known to establish symbioses with prokaryotic microorganisms. They are mainly phagotrophs and symbiotic relationships with bacteria can give them an important advantage in chemosynthetic environments. The aim of this study is to describe the thiotrophic association that occurs between the peritrich ciliate Pseudovorticella sp. and potential sulfur-oxidizing bacteria. Investigations at microscopic scale (LM, SEM, TEM) showed ectosymbiotic bacteria covering the surface of the body of Pseudovorticella sp. According to 16S rDNA phylogenetic analysis, these ectosymbiotic bacteria belong to-proteobacteria and are phylogenetically close to the symbiont of the recently described Zoothamnium ignavum, which inhabits shallow-water wood falls. FISH experiments, using symbiont specific probes, clearly indicate that these ectosymbiotic bacteria are also ingested into food vacuoles. Electron lucent granules observed in TEM in the cytoplasm of the ectosymbiotic bacteria have been identified as sulfur granules by Raman microspectrometry analyses. Raman microspec-trometry analyses confirmed the thiotrophic nature of this relationship already suggested by the results obtained by TEM and phylogeny. A complete sulfur map was then performed to investigate the sulfur distribution in the zooid. Results show that the relationship between this protist and its bacterial partner is a thiotrophic ectosymbiosis.

International audience; Friction and wear are the first causes of the decrease of the performances and the durability of mechanical systems. The role of lubrication is to minimise friction between the sliding surfaces and to protect them from wear. Conventional liquid lubricants are constituted of base oil and additives presenting specific properties, such as friction reduction, anti-wear or anti-oxidising action. Commercial lubricants generally use graphite and petroleum-based oils because of their recognised lubricating properties, their stability and low cost. However, such lubricants induce health and environmental hazards due to their life cycle. The aim of this work is to investigate the possibility to use local biomass in order to produce environmentally-friendly lubricants. Local vegetable oils are interesting candidates because of their inherent qualities like renewability, bio-degradability, non-toxicity. So, the first objective consists in finding an optimal mixture of mineral oil and vegetable oil validated by a compromise between environmental impact and cost of the lubricant. Our study mainly concerns the synthesis of new friction reducer additives. New carbon phases are obtained from glycolic solutions, stemming from by-products of our agriculture, using the spray-pyrolysis technique. This technique consists in nebulising in the form of micro-droplets a solution of saccharose, transported via a carrier neutral gas in a tubular oven heated at temperature ranging from 600°C to 1,000°C. Carbon nanoparticles are then obtained. Here are described the promising first results related to the determination of the optimal synthesis conditions, i.e. the catalyst concentration, the carrier gas pressure and the temperature of the tubular oven. Scanning electron microscopy and Raman spectrometry analyses are carried out, allowing us to observe the spherical shape and the porosity of the particles and to determine the graphitisation degree of the carbon phases.

International audience; Scaffolding proteins play important roles in supporting the plasma membrane (sarcolemma) of muscle cells. Among them, dystrophin strengthens the sarcolemma through protein-lipid interactions, and its absence due to gene mutations leads to the severe Duchenne muscular dystrophy. Most of the dystrophin protein consists of a central domain made of 24 spec-trin-like coiled-coil repeats (R). Using small angle neutron scattering (SANS) and the contrast variation technique, we specifically probed the structure of the three first consecutive repeats 1-3 (R1-3), a part of dystrophin known to physiologically interact with membrane lipids. R1-3 free in solution was compared to its structure adopted in the presence of phospholipid-based bicelles. SANS data for the protein/lipid complexes were obtained with contrast-matched bicelles under various phospholipid compositions to probe the role of electrostatic interactions. When bound to anionic bicelles, large modifications of the protein three-dimensional structure were detected, as revealed by a significant increase of the protein gyration radius from 42 5 1 to 60 5 4 Å. R1-3/anionic bicelle complexes were further analyzed by coarse-grained molecular dynamics simulations. From these studies, we report an all-atom model of R1-3 that highlights the opening of the R1 coiled-coil repeat when bound to the membrane lipids. This model is totally in agreement with SANS and click chemistry/mass spectrometry data. We conclude that the sarcolemma membrane anchoring that occurs during the contraction/elongation process of muscles could be ensured by this coiled-coil opening. Therefore, understanding these structural changes may help in the design of rationalized shortened dystrophins for gene therapy. Finally, our strategy opens up new possibilities for structure determination of peripheral and integral membrane proteins not compatible with different high-resolution structural methods.

The present work is concerned with the understanding of the tribologic behavior of fluorinated nanocarbons presenting various morphologies (0D spherical, 1D tubular, and 2D discotic structures). The intrinsic tribologic properties of the studied compounds are correlated to their structure and chemical composition (F/C ratio) to deduce the parameters monitoring the friction reduction mechanisms. Very low intrinsic friction coefficients are obtained for fluorinated carbon blacks, carbon nanofibers and carbon nanodiscs. The correlation between the tribologic results and structural investigations by transmission electron microscopy and friction force microscopy underlines different friction reduction mechanisms depending on the initial structure of the compounds. In the case of fluorinated carbon nanofibers and fluorinated carbon blacks, the friction improvement is attributed to interparticle interactions reduction resulting from surface energy decrease induced by the fluorination of superficial (external) graphene layers. For fluorinated carbon nanodiscs, bulk structural effects are predominant. Long-term tribologic experiments lead to evolutions of the structure and the composition of the tribofilms, underlined by Raman and SEM investigations. The friction process leads to an amorphization and a partial defluorination on the compounds. The tested carbon nanostructures appear as interesting candidates to be used as new nanoadditives for lubricants. The control of the fluorination conditions allows to achieve optimized friction properties.

International audience

International audience; Un lubrifiant liquide est composé d'une base (huile minérale ou de synthèse) à laquelle sont ajoutés des additifs conférant au lubrifiant ses propriétés. Les additifs réducteurs de frottement et d'usure conventionnels (dialkyl dithiophosphates de métaux de transition) qui présentent une efficacité remarquable dans le cas de pièces frottantes en alliage ferreux 1 , deviennent peu efficients dans le cas de matériaux peu réactifs. De plus, les surfaces subissent une usure sévère durant la période de formation du film tribologique protecteur. Ainsi, les nouvelles stratégies de lubrification utilisent des particules colloïdales en dispersion dans la base. Ces nanoparticules sont susceptibles de constituer instantanément le film tribologique sans réaction chimique avec les substrats 3. Les phases tribo-actives choisies sont généralement des matériaux lamellaires (MoS 2 , graphite, graphites fluorés) présentant de bonnes propriétés tribologiques intrinsèques. Les travaux menés sur les carbones fluorés CF x 4 permettent d'envisager les formes nanostructurées comme une nouvelle famille de nano-additifs pour lubrifiants. Dans cette étude, les propriétés tribologiques de nanocarbones présentant différentes morphologies (sphérique (0D) : noirs de carbone (GCBs) ; tubulaire (1D) : nanofibres (CNFs) et discotique (2D) : nanodisques (CNDs)) sont déterminées en fonction du degré de fluoration des composés. Les excellentes propriétés réductrices de frottement des composés sont illustrées sur la figure 1. De très faibles coefficients de frottement sont obtenus (  0,08) pour les trois types de nanostructures. La figure 1 met également en évidence des comportements tribologiques différents selon la structure initiale des nanocarbones. En effet, la présence de fluor améliore nettement les propriétés tribologiques des nanofibres et noirs de carbone (le coefficient de frottement diminue à mesure que le taux de fluoration augmente pour atteindre une valeur asymptotique pour un rapport atomique F/C = 0,15 pour les CNFs et 0,6 pour les GCBs) tandis que dans les cas des nanodisques de carbone, l'influence de la fluoration est nettement moins significative. La corrélation des propriétés tribologiques avec l'analyse de l'évolution structurale des nanocarbones (par MEB, MET, spectrométrie Raman) permet de mettre en évidence un processus de réduction du frottement lié à des phénomènes de surface dans le cas des CNFs et GCBs et de « bulk » dans le cas des CNDs 5. Figure 1: Evolution du coefficient de frottement intrinsèque des nanodisques (CNDs), nanofibres (CNFs) et noirs de carbone (GCBs) fluorés en fonction du taux de fluoration.

International audience; Dystrophin is a large skeletal muscle protein located at the internal face of the plasma membrane and interacting with membrane phospholipids and a number of cytosolic proteins. Binding of neuronal nitric oxide synthase (nNOS) to dystrophin appears to be crucial for exercise-induced increases in blood supply in muscle cells. By contrast, utrophin, the developmental homologous protein of dystrophin, does not display nNOS interaction. Recent in vitro and in vivo experiments showed that the dystrophin region involved in nNOS binding is located in spectrin-like repeats R16 and R17 of its filamentous central domain. Using homology modeling and atomistic molecular dynamics simulation, we compared the structural organization and surface potentials of dystrophin, utrophin, and chimeric fragments, thus revisiting the dystrophin-nNOS binding region. Our simulation results are in good agreement with experimental data. They provide a three-dimensional representation of the repeats and give insight into the molecular organization of the regions involved in dystrophin-nNOS interaction. This study also further elucidates the physical properties crucial for this interaction, particularly the presence of a large hydrophobic patch. These results will be helpful to improving our understanding of the phenotypic features of patients bearing mutations in the nNOS-binding region of dystrophin.

International audience; A finely tuned balance of translation, storage and decay of mRNAs (mRNAs) is important for the regulation of gene expression. In eukaryotic cells, this takes place in dynamic cytoplasmic RNA-protein granules termed Processing bodies (P-bodies). In this study, by using immunoelectron tomography, 3D modeling and template matching, we analyze the size and the organization of the polysomes in the vicinity of human P-bodies. Our results show the presence of several polysomes that are compatible with a translational activity around P-bodies. Therefore, movement of mRNAs between polysomes and P-bodies can take place when the two compartments are in close contact. The presence of initiation factors in the proximity of P-bodies also suggests that translation of mRNAs can resume at the periphery of these granules.

It has been shown that friction coefficient of powdered lamellar compounds measured at macroscale undergoes a drastic decrease when the experiments are performed in the presence of a low-viscosity liquid. The effect was attributed to the simultaneous presence of the solid particles and the liquid in the area of contact. However, the friction reduction mechanisms are still not yet fully understood. Recently, it was found by Atomic Force Microscopy that the presence of liquid during graphite tribofilm built-up induced a nanostructuration of the film surface and it has been demonstrated that such structuration has no influence on the tribological properties measured at macroscale. In this work, we report structural and friction analyses of MoS2 tribofilms performed at nano- and macroscales, in comparison with graphite tribofilms. In addition, MoS2 and graphite tribofilm structure are investigated by means of transmission electron microscopy. The results clearly indicate that, at macroscale, friction does not always take place at the surface but could occur inside of the tribofilm depending on its nanostructuration.

International audience; no abstract

International audience; Duchenne muscular dystrophy is a lethal genetic defect that is associated with the absence of dystrophin protein. Lack of dystrophin protein completely abolishes muscular nitric oxide synthase (NOS) function as a regulator of blood flow during muscle contraction. In normal muscles, nNOS function is ensured by its localization at the sarcolemma through an interaction of its PDZ domain with dystrophin spectrin-like repeats R16 and R17. Early studies suggested that repeat R17 is the primary site of interaction but ignored the involved nNOS residues, and the R17 binding site has not been described at an atomic level. In this study, we characterized the specific amino acids involved in the binding site of nNOS-PDZ with dystrophin R16-17 using combined experimental biochemical and structural in silico approaches. First, 32 alanine-scan mutagenesis variants of dystrophin R16-17 indicated the regions where mutagenesis modified the affinity of the dystrophin interaction with the nNOS-PDZ. Second, using small angle X-ray scattering-based models of dystrophin R16-17 and molecular docking methods, we generated atomic models of the dystrophin R16-17: nNOS-PDZ complex that correlated well with the alanine-scanning-identified regions of dystrophin. The structural regions constituting the dystrophin interaction surface involve the A/B loop and the N-terminal end of helix B of repeat R16 and the N-terminal end of helix A' and a small fraction of helix B' and a large part of the helix C' of repeat R17. The interaction surface of nNOS-PDZ involves its main β-sheet and its specific C-terminal β-finger.

International audience

International audience; The tribologic properties of graphitized carbon blacks and their fluorinated derivatives are investigated as a function of the fluorination rate. Very low intrinsic friction coefficients are obtained for highly fluorinated compounds. The correlation of the tribologic results and structural investigations of the initial compounds by TEM strongly suggests that the friction mechanisms involve surface effects in the early stage of friction. Long-term tribologic experiments and Raman analyses point out an evolution of the structure and composition of the tribofilms during the friction process leading to similar friction properties of the tribofilms. Wear studies revealed that highly fluorinated derivatives appear less efficient than pristine and weakly fluorinated compounds.

International audience; During protein synthesis, many translating ribosomes are bound together with an mRNA molecule to form polysomes (or polyribosomes). While the spatial organization of bacterial polysomes has been well studied in vitro, little is known about how they cluster when cellular conditions are highly constrained. To better understand this, we used electron tomography, template matching, and three-dimensional modeling to analyze the supramolecular network of ribosomes after induction of translational pauses. In Escherichia coli, we overexpressed an mRNA carrying a polyproline motif known to induce pausing during translation. When working with a strain lacking transfer-messenger RNA, the principle actor in the "trans-translation" rescuing system, the cells survived the hijacking of the translation machinery but this resulted in a sharp modification of the ribosomal network. The results of our experiments demonstrate that single ribosomes are replaced with large amounts of compacted polysomes. These polysomes are highly organized, principally forming hairpins and dimers of hairpins that stack together. We propose that these spatial arrangements help maintain translation efficiency when the rescue systems are absent or overwhelmed.

International audience

The control of gastrointestinal nematodes requires an understanding of their epidemiology so that particular parasite stages can be targeted. Dam infection during early lactation is one example of this in ruminant nematode infections. The existence of the peri-parturient relaxation in immunity and its impact on productivity were examined in a Creole goat flock from Guadeloupe, exposed to mixed natural infection (predominantly Haemonchus contortus and Trichostrongylus colubriformis). A total of 1,511 l were obtained from 909 does resulting from 463 dams and 150 sires. Fecal and blood samples were collected at kidding before anthelmintic drenching, 4 and 6 weeks after kidding. The traits analyzed were logarithm transformed fecal egg counts (FEC), packed cell volume (PCV), and logarithm transformed blood eosinophilia counts (EOS) for does at each sampling point and changes in these during the postpartum period. With the exception of the PCV values measured at kidding, lactating does had significantly higher FEC and lower PCV than control dry does at every sampling point. Geometric means of FEC in lactating does were 819 +/- 174, 677 +/- 146 and, 699 +/- 160 eggs per gram (EPG) at kidding, 4 and 6 weeks after kidding respectively. Geometric means of FEC in dry does were 187 +/- 57, 89 +/- 28, 133 +/- 43 at these time points, respectively. EOS differences were not consistent between groups and probably not specific enough for variations in Creole goats' peri-parturient rise to be discussed. As does aged, their egg output decreased and primiparous does always had greater egg output than multiparous ones. Overall, does' FEC at 4 weeks after kidding decreased by 1.3% each year. The higher the litter size, the higher the FEC at kidding and inverse applied for PCV measurements. Does that stopped lactating had significantly lower FEC and higher PCV values than lactating does with low milk yields. Higher infection rates during early lactation in Creole goats were recorded in does with lower maternal ability assessed by the average daily weight gain of kids between 10 and 30 days of age. Kids from dams with higher FEC (i.e. >600 EPG higher than corresponding does) had 17% lower average daily weight gain between 30 and 70 days postpartum and were approximately 1 kg lighter at weaning than kids from dams with lower FEC. Thus, it is clear that a peri-parturient rise in FEC exists in Creole goats. By controlling the intensity of this peri-parturient rise in FEC, herd health and productivity could be substantially improved.