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This work studies the dependency of the effective lifetime on the a-Si:H layer thickness of c-Si substrates passivated with intrinsic a-Si:H. This is experimentally investigated by using a soft wet-etching method that enables accurate control of the a-Si:H layer thickness. In this way, variations in the effective lifetime down to thicknesses of a few nanometers are studied, while excluding effects originating from the deposition conditions of a-Si:H when samples of different thicknesses are fabricated. For thin passivation layers, results show a strong thickness dependency of the effective lifetime, which is mainly influenced by the recombination at the external a-Si:H surfaces. For thicker passivation layers, the effective lifetime is predominantly determined by the bulk a-Si:H and/or c-Si defect density. During the etching of the a-Si:H passivation layers, a gradient in the Cody gap for our samples is observed. This gradient is accompanied by a stronger decrease in the effective lifetime and is attributed to a decrease in the a-Si:H band gap and valence band offset. The observed changes in lifetime with a-Si:H layer thickness are supported with AFORS-HET simulations. When a gradient in the a-Si:H passivation layer band gap is used, simulations can reproduce the experimental results. [ABSTRACT FROM AUTHOR]

Gastroesophageal reflux disease (GERD) is a common disorder of the upper gastrointestinal tract which is typically characterized by heartburn and acid regurgitation. These symptoms are widespread in the community and range from 2.5% to more than 25%. Economic analyses showed an increase in direct and indirect costs related to the diagnosis, treatment and surveillance of GERD and its complications. The aim of this review is to provide current information regarding the natural history of GERD, taking into account the evolution of its definition and the worldwide gradual change of its epidemiology. Present knowledge shows that there are two main forms of GERD, that is erosive reflux disease (ERD) and non-erosive reflux disease (NERD) and the latter comprises the majority of patients (up to 70%). The major complication of GERD is the development of Barrett esophagus, which is considered as a pre-cancerous lesion. Although data from medical literature on the natural history of this disease are limited and mainly retrospective, they seem to indicate that both NERD and mild esophagitis tend to remain as such with time and the progression from NERD to ERD, from mild to severe ERD and from ERD to Barrett's esophagus may occur in a small proportion of patients, ranging from 0 to 30%, 10 to 22% and 1 to 13% of cases, respectively. It is necessary to stress that these data are strongly influenced by the use of powerful antisecretory drugs (PPIs). Further studies are needed to better elucidate this matter and overcome the present limitations represented by the lack of large prospective longitudinal investigations, absence of homogeneous definitions of the various forms of GERD, influence of different treatments, clear exclusion of patients with functional disorders of the esophagus. [ABSTRACT FROM AUTHOR]

Background Little is known about the relationship between proton pump inhibitor-responsive oesophageal eosinophilia ( PPI- REE), eosinophilic esophagitis (EoE) and gastro-oesophageal reflux disease ( GERD). Aim To compare high resolution manometry features and symptom profiles of patients with EoE, PPI- REE and GERD. Methods Consecutive patients diagnosed with EoE or PPI- REE according to international criteria (presence of at least one typical symptom of oesophageal dysfunction; at least 15 eosinophils per high-power field at mid/proximal oesophagus, persistence or resolution of eosinophils after an 8-week PPI trial), and a group of patients with proven GERD and oesophageal eosinophilia, prospectively completed the GerdQ questionnaire and underwent high resolution manometry. Results Thirty-five patients with EoE, 17 with PPI- REE and 27 with GERD were enrolled. When compared to GERD, both EoE and PPI- REE had higher rates of dysphagia (15% vs. 94% vs. 88%, P < 0.0001), patients with EoE reported heartburn and regurgitation less frequently (26% vs. 85%, and 17% vs. 74%, respectively; P < 0.001 for each and had lower GerdQ score [1 (0-6) vs. 8 (6-12), P < 0.001] than GERD patients. There was no significant difference comparing PPI-REE and GERD patients. Patients with PPI-REE had a higher prevalence of erosive oesophagitis than patients with EoE (35% vs. 9%, P = 0.04), which was similar to that of GERD (48%, P = 0.54). Patients with EoE had a lower frequency of high resolution manometry features associated with GERD than patients with PPI-REE. There was no significant difference between PPI-REE and GERD patients. Conclusion GERD, as assessed by GerdQ and high resolution manometry is common in patients with PPI-REE, which may share similar pathogenic mechanisms. [ABSTRACT FROM AUTHOR]

Alnus glutinosa , able to establish symbiosis with mutualistic bacteria of the genus Frankia , is one of the main species in European riparian environments, where it performs numerous biological and socio-economic functions. However, riparian ecosystems face a growing threat from Phytophthora alni , a highly aggressive waterborne pathogen causing severe dieback in A. glutinosa . To date, the tripartite interaction between the host plant, the symbiont Frankia and the pathogen remains unexplored but is critical for understanding how pathogen-induced stress influences the nodule molecular machinery and so on the host-symbiont metabolism. In the present study, we aimed to explore for the first time how P. alni affects the overall molecular processes of Alnus glutinosa - Frankia nodules, with a special focus on unraveling the spatial expression of defense mechanisms within these tissues. We conducted a laboratory experiment based on P. alni infection of young A. glutinosa seedlings nodulated with Frankia alni ACN14a, non-infected or infected with the pathogen P. alni . Multi-omics analyses were carried out on nodules (N) and associated roots (AR) of the same plant in order to underline the impact on the nodule molecular processes (i.e. N/AR markers) when the host plant is infected compared to non-infected plants. Our results revealed that P. alni infection modified the molecular nodule processes and induced reprograming of defense-related markers by a shift in associated roots to the detriment of nodules. These findings suggest that A. glutinosa reinforces locally its immune responses in roots but moderates this activation in nodule to preserve its Frankia symbiont.

Plasmodium malariae is the third most prevalent human malaria parasite species and contributes significantly to morbidity. Nevertheless, our comprehension of this parasite's biology remains limited, primarily due to its frequent co-infections with other species and the lack of a continuous in vitro culture system. To effectively combat and eliminate this overlooked parasite, it is imperative to acquire a better understanding of this species. In this study, we embarked on an investigation of P. malariae, including exploring its clinical disease characteristics, molecular aspects of red blood cell (RBC) invasion, and host-cell preferences. We conducted our research using parasites collected from infected individuals in Mali. Our findings revealed anaemia in most of P. malariae infected participants presented, in both symptomatic and asymptomatic cases. Regarding RBC invasion, quantified by an adapted flow cytometry based method, our study indicated that none of the seven antibodies tested, against receptors known for their role in P. falciparum invasion, had any impact on the ability of P. malariae to penetrate the host cells. However, when RBCs were pre-treated with various enzymes (neuraminidase, trypsin, and chymotrypsin), we observed a significant reduction in P. malariae invasion, albeit not a complete blockade. Furthermore, in a subset of P. malariae samples, we observed the parasite's capability to invade reticulocytes. These results suggest that P. malariae employs alternative pathways to enter RBCs of different maturities, which may differ from those used by P. falciparum., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2025 Dao et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Nitrogen (N) fertilization is essential to maximize crop production. However, around half of the applied N is lost to the environment, causing water and air pollution and contributing to climate change. Understanding the natural genetic and metabolic basis underlying plants N use efficiency is of great interest to attain an agriculture with less N demand and thus more sustainable. The study of ammonium (NH4+) nutrition is of particular interest, because it mitigates N losses due to nitrate (NO3-) leaching or denitrification. In this work, we studied Brachypodium distachyon, the model plant for C3 grasses, grown with NH4+ or NO3- supply. We performed gene expression analysis in the root of the B. distachyon reference accession Bd21 and examined the phenotypic variation across 52 natural accessions through analyzing plant growth and a panel of 22 metabolic traits in leaf and root. We found that the adjustment of primary metabolism to NH4+ nutrition is essential for the natural variation of NH4+ tolerance, notably involving NH4+ assimilation and phosphoenolpyruvate carboxylase (PEPC) activity. Additionally, genome-wide association studies (GWAS) indicated several loci associated with B. distachyon growth and metabolic adaptation to NH4+ nutrition. We found that the GDH2 gene was associated with the induction of root glutamate dehydrogenase activity under NH4+ nutrition and that two genes encoding malic enzyme were associated with leaf PEPC activity. Altogether, our work underlines the value of natural variation and the key role of primary metabolism to improve NH4+ tolerance., (© The Author(s) 2024. Published by Oxford University Press on behalf of the Society for Experimental Biology.)

Malate and fumarate constitute a significant fraction of the carbon fixed by photosynthesis, and they are at the crossroad of central metabolic pathways. In Arabidopsis thaliana, they are transiently stored in the vacuole to keep cytosolic homeostasis. The malate and fumarate transport systems of the vacuolar membrane are key players in the control of cell metabolism. Notably, the molecular identity of these transport systems remains mostly unresolved. We used a combination of imaging, electrophysiology and molecular physiology to identify an important molecular actor of dicarboxylic acid transport across the tonoplast. Here, we report the function of the A. thaliana Aluminium-Activated Malate Transporter 5 (AtALMT5). We characterised its ionic transport properties, expression pattern, localisation and function in vivo. We show that AtALMT5 is expressed in photosynthetically active tissues and localised in the tonoplast. Patch-clamp and in planta analyses demonstrated that AtALMT5 is an ion channel-mediating fumarate loading of the vacuole. We found in almt5 plants a reduced accumulation of fumarate in the leaves, in parallel with increased malate concentrations. These results identified AtALMT5 as an ion channel-mediating fumarate transport in the vacuoles of mesophyll cells and regulating the malate/fumarate balance in Arabidopsis., (© 2024 The Author(s). New Phytologist © 2024 New Phytologist Foundation.)

Sugar limitation has dramatic consequences on plant cells, which include cell metabolism and transcriptional reprogramming, and the recycling of cellular components to maintain fundamental cell functions. There is however no description of the contribution of epigenetic regulations to the adaptation of plant cells to limited carbon availability. We investigated this question using nonphotosynthetic grapevine cells ( Vitis vinifera , cv Cabernet Sauvignon) cultured in vitro with contrasted glucose concentrations. Sugar depletion in the culture medium led to a rapid cell growth arrest and a major metabolic shift that include the depletion in soluble sugar and total amino acids and modulation of the cell redox status. Consistently, flux modeling showed a dramatic slowdown of many pathways required for biomass accumulation such as cell wall and protein synthesis. Sugar depletion also resulted in a major transcriptional reprogramming, characterized by the induction of genes involved in photosynthesis, and the repression of those related to sucrose mobilization or cell cycle control. Similarly, the epigenetic landscape was deeply modified. Glucose-depleted cells showed a higher global DNA methylation level than those grown with glucose. Changes in DNA methylation mainly occurred at transposable elements, and at genes including some of those differentially expressed, consistent with an important role for methylation to the adaptation of cells to limited sugar availability. In addition, genes encoding histone modifiers were differentially expressed suggesting that additional epigenetic mechanisms may be at work in plant cells under carbon shortage., Competing Interests: The authors declare that they have no conflicts of interest., (© The Author(s) 2024. Published by Oxford University Press on behalf of Nanjing Agricultural University.)

Plant defence peptides are paramount endogenous danger signals secreted after a challenge, intensifying the plant immune response. The peptidic hormone Systemin (Sys) was shown to participate in resistance in several plant pathosystems, although the mechanisms behind Sys-induced resistance when exogenously applied remain elusive. We performed proteomic, metabolomic, and enzymatic studies to decipher the Sys-induced changes in tomato plants in either the absence or the presence of Botrytis cinerea infection. Sys treatments triggered direct proteomic rearrangement mostly involved in carbon metabolism and photosynthesis. However, the final induction of defence proteins required concurrent challenge, triggering priming of pathogen-targeted proteins. Conversely, at the metabolomic level, Sys-treated plants showed an alternative behaviour following a general priming profile. Of the primed metabolites, the flavonoids rutin and isorhamnetin and two alkaloids correlated with the proteins 4-coumarate-CoA-ligase and chalcone-flavanone-isomerase triggered by Sys treatment. In addition, proteomic and enzymatic analyses revealed that Sys conditioned the primary metabolism towards the production of available sugars that could be fuelling the priming of callose deposition in Sys-treated plants; furthermore, PR1 appeared as a key element in Sys-induced resistance. Collectively, the direct induction of proteins and priming of specific secondary metabolites in Sys-treated plants indicated that post-translational protein regulation is an additional component of priming against necrotrophic fungi., (© The Author(s) 2024. Published by Oxford University Press on behalf of the Society for Experimental Biology. All rights reserved. For commercial re-use, please contact reprints@oup.com for reprints and translation rights for reprints. All other permissions can be obtained through our RightsLink service via the Permissions link on the article page on our site—for further information please contact journals.permissions@oup.com.)

Background: During the summer of 2021, a deadly, unprecedented multiday Heat Dome engulfed western Canada. As a result of this extreme heat event (EHE), emergency dispatchers received an unparalleled increase in incoming 911 calls for ambulance, police, and fire (as first responders) services to attend to hundreds of heat-vulnerable community members succumbing to the heat. With 103 all-time heat records broken during this EHE and indoor temperatures of nearly 40°C, the first responders attending these calls faced extensive job demands and highly challenging operating conditions. Initial investigations have explored the health system-level impacts; however, little has been done to explore the impact on the first responders themselves. Therefore, this study aimed to improve our understanding of EHEs' impacts on the operational capabilities and health of first responders, specifically police, fire, ambulance, and dispatch services., Methods: A systematized review and content analysis of media articles published on the 2021 Heat Dome in Canada was conducted (n = 2909), and four media-based composite narratives were developed highlighting police, fire, ambulance, and dispatch services. The Job Demands-Resources (JD-R) model was applied as a theoretical framework for occupational burnout., Results: The media-based composite narratives highlighted that first responders faced record-breaking call volumes, increased mental-health-related claims, and exhaustive heat-related physiological stress. Using the JD-R model as a theoretical framework for occupational burnout, we identified three measures of stressful job demand: work overload (e.g., the surge in call volume, firefighters responding to medical emergencies), emotional demands (e.g., severe medical emergencies, sudden deaths, unresponsive patients, distraught family members), and physical demands (e.g., resuscitation in personal protective equipment, heat-related illness)., Conclusion: The experiences described underscore the importance of supporting first responders during work in extreme heat conditions. These findings have important implications for addressing rising rates of burnout during and following public health crises, such as EHEs, a problem that is increasingly being recognized as a threat to the Canadian public healthcare system., (© 2024 The Authors. American Journal of Industrial Medicine published by Wiley Periodicals LLC.)

Key Message: Different wheat QTLs were associated to the free asparagine content of grain grown in four different conditions. Environmental effects are a key factor when selecting for low acrylamide-forming potential. The amount of free asparagine in grain of a wheat genotype determines its potential to form harmful acrylamide in derivative food products. Here, we explored the variation in the free asparagine, aspartate, glutamine and glutamate contents of 485 accessions reflecting wheat worldwide diversity to define the genetic architecture governing the accumulation of these amino acids in grain. Accessions were grown under high and low nitrogen availability and in water-deficient and well-watered conditions, and plant and grain phenotypes were measured. Free amino acid contents of grain varied from 0.01 to 1.02 mg g -1 among genotypes in a highly heritable way that did not correlate strongly with grain yield, protein content, specific weight, thousand-kernel weight or heading date. Mean free asparagine content was 4% higher under high nitrogen and 3% higher in water-deficient conditions. After genotyping the accessions, single-locus and multi-locus genome-wide association study models were used to identify several QTLs for free asparagine content located on nine chromosomes. Each QTL was associated with a single amino acid and growing environment, and none of the QTLs colocalised with genes known to be involved in the corresponding amino acid metabolism. This suggests that free asparagine content is controlled by several loci with minor effects interacting with the environment. We conclude that breeding for reduced asparagine content is feasible, but should be firmly based on multi-environment field trials., Key Message: Different wheat QTLs were associated to the free asparagine content of grain grown in four different conditions. Environmental effects are a key factor when selecting for low acrylamide-forming potential., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Plant-plant positive interactions are key drivers of community structure. Yet, the underlying molecular mechanisms of facilitation processes remain unexplored. We investigated the 'nursing' effect of Maihueniopsis camachoi, a cactus that thrives in the Atacama Desert between c. 2800 and 3800 m above sea level. We hypothesised that an important protective factor is thermal amelioration of less cold-tolerant species with a corresponding impact on molecular phenotypes. To test this hypothesis, we compared plant cover and temperatures within the cactus foliage with open areas and modelled the effect of temperatures on plant distribution. We combined eco-metabolomics and machine learning to test the molecular consequences of this association. Multiple species benefited from the interaction with M. camachoi. A conspicuous example was the extended distribution of Atriplex imbricata to colder elevations in association with M. camachoi (400 m higher as compared to plants in open areas). Metabolomics identified 93 biochemical markers predicting the interaction status of A. imbricata with 79% accuracy, independently of year. These findings place M. camachoi as a key species in Atacama plant communities, driving local biodiversity with an impact on molecular phenotypes of nursed species. Our results support the stress-gradient hypothesis and provide pioneer insights into the metabolic consequences of facilitation., (© 2023 The Authors. New Phytologist © 2023 New Phytologist Foundation.)

Although primary metabolism is well conserved across species, it is useful to explore the specificity of its network to assess the extent to which some pathways may contribute to particular outcomes. Constraint-based metabolic modelling is an established framework for predicting metabolic fluxes and phenotypes and helps to explore how the plant metabolic network delivers specific outcomes from temporal series. After describing the main physiological traits during fruit development, we confirmed the correlations between fruit relative growth rate (RGR), protein content and time to maturity. Then a constraint-based method is applied to a panel of eight fruit species with a knowledge-based metabolic model of heterotrophic cells describing a generic metabolic network of primary metabolism. The metabolic fluxes are estimated by constraining the model using a large set of metabolites and compounds quantified throughout fruit development. Multivariate analyses showed a clear common pattern of flux distribution during fruit development with differences between fast- and slow-growing fruits. Only the latter fruits mobilise the tricarboxylic acid cycle in addition to glycolysis, leading to a higher rate of respiration. More surprisingly, to balance nitrogen, the model suggests, on the one hand, nitrogen uptake by nitrate reductase to support a high RGR at early stages of cucumber and, on the other hand, the accumulation of alkaloids during ripening of pepper and eggplant. Finally, building virtual fruits by combining 12 biomass compounds shows that the growth-defence trade-off is supported mainly by cell wall synthesis for fast-growing fruits and by total polyphenols accumulation for slow-growing fruits., (© 2023 The Authors. The Plant Journal published by Society for Experimental Biology and John Wiley & Sons Ltd.)

Background: Toxocara canis is a cosmopolitan parasite of dogs that is transmitted transplacentally to puppies resulting in widespread shedding of eggs in the environment. However, it is not clear if there are dominant parasite genotypes that are more common, pathogenic, or likely to be zoonotic., Methods/principle Findings: Sequences of mitochondrial cox1 gene from adult worms were used to compare parasites from the United States with submitted sequences from parasites isolated from dogs in different countries. Our analysis revealed at least 55 haplotypes. While we expected the North American worms to form a distinct cluster, we found haplotypes of T. canis reported elsewhere existing in this population. Interestingly, combining the sequence data from our study with the available GenBank data, analysis of cox1 sequences results in five distinct clades that are not geographically defined., Conclusions: The five clades of T. canis revealed in this study potentially have unique life histories, traits, or host preferences. Additional investigation is needed to see if these distinct clades represent cryptic species with clinically useful attributes or genotypes with taxonomic value. Evaluation of common mitochondrial genes may reveal distinct populations of zoonotic T. canis., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2023 Martin et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

The ascorbate-glutathione (ASC-GSH) cycle is at the heart of redox metabolism, linking the major redox buffers with central metabolism through the processing of reactive oxygen species (ROS) and pyridine nucleotide metabolism. Tomato fruit development is underpinned by changes in redox buffer contents and their associated enzyme capacities, but interactions between them remain unclear. Based on quantitative data obtained for the core redox metabolism, we built an enzyme-based kinetic model to calculate redox metabolite concentrations with their corresponding fluxes and control coefficients. Dynamic and associated regulations of the ASC-GSH cycle throughout the whole fruit development were analysed and pointed to a sequential metabolic control of redox fluxes by ASC synthesis, NAD(P)H and ROS availability depending on the developmental phase. Furthermore, we highlighted that monodehydroascorbate reductase and the availability of reducing power were found to be the main regulators of the redox state of ASC and GSH during fruit growth under optimal conditions. Our kinetic modelling approach indicated that tomato fruit development displayed growth phase-dependent redox metabolism linked with central metabolism via pyridine nucleotides and H 2 O 2 availability, while providing a new tool to the scientific community to investigate redox metabolism in fruits., (© 2023 The Authors New Phytologist © 2023 New Phytologist Foundation.)

Tree stem respiration (R S ) is a substantial component of the forest carbon balance. The mass balance approach uses stem CO 2 efflux and internal xylem fluxes to sum up R S , while the oxygen-based method assumes O 2 influx as a proxy of R S . So far, both approaches have yielded inconsistent results regarding the fate of respired CO 2 in tree stems, a major challenge for quantifying forest carbon dynamics. We collected a data set of CO 2 efflux, O 2 influx, xylem CO 2 concentration, sap flow, sap pH, stem temperature, nonstructural carbohydrates concentration and potential phosphoenolpyruvate carboxylase (PEPC) capacity on mature beech trees to identify the sources of differences between approaches. The ratio of CO 2 efflux to O 2 influx was consistently below unity (0.7) along a 3-m vertical gradient, but internal fluxes did not bridge the gap between influx and efflux, nor did we find evidence for changes in respiratory substrate use. PEPC capacity was comparable with that previously reported in green current-year twigs. Although we could not reconcile differences between approaches, results shed light on the uncertain fate of CO 2 respired by parenchyma cells across the sapwood. Unexpected high values of PEPC capacity highlight its potential relevance as a mechanism of local CO 2 removal, which merits further research., (© 2023 The Authors. Plant, Cell & Environment published by John Wiley & Sons Ltd.)

Ascorbate (vitamin C) is an essential antioxidant in fresh fruits and vegetables. To gain insight into the regulation of ascorbate metabolism in plants, we studied mutant tomato plants (Solanum lycopersicum) that produce ascorbate-enriched fruits. The causal mutation, identified by a mapping-by-sequencing strategy, corresponded to a knock-out recessive mutation in a class of photoreceptor named PAS/LOV protein (PLP), which acts as a negative regulator of ascorbate biosynthesis. This trait was confirmed by CRISPR/Cas9 gene editing and further found in all plant organs, including fruit that accumulated 2 to 3 times more ascorbate than in the WT. The functional characterization revealed that PLP interacted with the 2 isoforms of GDP-L-galactose phosphorylase (GGP), known as the controlling step of the L-galactose pathway of ascorbate synthesis. The interaction with GGP occurred in the cytoplasm and the nucleus, but was abolished when PLP was truncated. These results were confirmed by a synthetic approach using an animal cell system, which additionally demonstrated that blue light modulated the PLP-GGP interaction. Assays performed in vitro with heterologously expressed GGP and PLP showed that PLP is a noncompetitive inhibitor of GGP that is inactivated after blue light exposure. This discovery provides a greater understanding of the light-dependent regulation of ascorbate metabolism in plants., Competing Interests: Conflict of interest statement. None declared., (© The Author(s) 2023. Published by Oxford University Press on behalf of American Society of Plant Biologists.)

Differences in codon frequency between genomes, genes, or positions along a gene, modulate transcription and translation efficiency, leading to phenotypic and functional differences. Here, we present a multiscale analysis of the effects of synonymous codon recoding during heterologous gene expression in human cells, quantifying the phenotypic consequences of codon usage bias at different molecular and cellular levels, with an emphasis on translation elongation. Six synonymous versions of an antibiotic resistance gene were generated, fused to a fluorescent reporter, and independently expressed in HEK293 cells. Multiscale phenotype was analyzed by means of quantitative transcriptome and proteome assessment, as proxies for gene expression; cellular fluorescence, as a proxy for single-cell level expression; and real-time cell proliferation in absence or presence of antibiotic, as a proxy for the cell fitness. We show that differences in codon usage bias strongly impact the molecular and cellular phenotype: (i) they result in large differences in mRNA levels and protein levels, leading to differences of over 15 times in translation efficiency; (ii) they introduce unpredicted splicing events; (iii) they lead to reproducible phenotypic heterogeneity; and (iv) they lead to a trade-off between the benefit of antibiotic resistance and the burden of heterologous expression. In human cells in culture, codon usage bias modulates gene expression by modifying mRNA availability and suitability for translation, leading to differences in protein levels and eventually eliciting functional phenotypic changes., (© 2023 The Protein Society.)

Although antibiotic resistance is a major issue for both human and animal health, very few studies have investigated the role of the bacterial host spectrum in its dissemination within natural ecosystems. Here, we assessed the prevalence of methicillin resistance among Staphylococcus aureus (MRSA) isolates from humans, non-human primates (NHPs), micromammals and bats in a primatology center located in southeast Gabon, and evaluated the plausibility of four main predictions regarding the acquisition of antibiotic resistance in this ecosystem. MRSA strain prevalence was much higher in exposed species (i.e., humans and NHPs which receive antibiotic treatment) than in unexposed species (micromammals and bats), and in NHP species living in enclosures than those in captivity-supporting the assumption that antibiotic pressure is a risk factor in the acquisition of MRSA that is reinforced by the irregularity of drug treatment. In the two unexposed groups of species, resistance prevalence was high in the generalist strains that infect humans or NHPs, supporting the hypothesis that MRSA strains diffuse to wild species through interspecific transmission of a generalist strain. Strikingly, the generalist strains that were not found in humans showed a higher proportion of MRSA strains than specialist strains, suggesting that generalist strains present a greater potential for the acquisition of antibiotic resistance than specialist strains. The host spectrum is thus a major component of the issue of antibiotic resistance in ecosystems where humans apply strong antibiotic pressure.

Visceral leishmaniasis is not endemic in West Africa, but prevalence of canine leishmaniasis and seroprevalence of Leishmania infantum infection in humans are high in the Mont Rolland community (Thiès region, Senegal). Previous studies in this area showed that Sergentomyia schwetzi could be the potential vector of Le. infantum. To precisely describe the biology and population structure of this potential vector, we identified eight novel microsatellite loci to characterize Se. schwetzi populations. We tested these loci in Se. schwetzi populations from five locations at Mont Rolland (Thiès, Senegal). All the loci were polymorphic, with a mean of 17.25 alleles (observed heterozygosity: 0.455). We did not detect any evidence of scoring errors due to stuttering and large allele dropout. Moreover, several of these loci were also amplified in six other sand fly species (Sergentomyia magna, Sergentomyia dubia, Sergentomyia minuta, Phlebotomus duboscqi, Phlebotomus perniciosus, and Phlebotomus ariasi). These preliminary results demonstrate the utility of these microsatellite markers for Se. schwetzi (and for the other sand fly species) population genetic studies., (© The Author(s) 2022. Published by Oxford University Press on behalf of Entomological Society of America.)

In this study, we aimed to investigate for the first time different fruit development stages in plantain banana in order gain insights into the order of appearance and dominance of specific enzymes and fluxes. We examined fruit development in two plantain banana cultivars during the period between 2-12 weeks after bunch emergence using high-throughput proteomics, quantification of major metabolites, and analyses of metabolic fluxes. Starch synthesis and breakdown are processes that take place simultaneously. During the first 10 weeks fruits accumulated up to 48% of their dry weight as starch, and glucose 6-phosphate and fructose were important precursors. We found a unique amyloplast transporter and hypothesize that it facilitates the import of fructose. We identified an invertase originating from the Musa balbisiana genome that would enable carbon flow back to growth and starch synthesis and maintain a high starch content even during ripening. Enzymes associated with the initiation of ripening were involved in ethylene and auxin metabolism, starch breakdown, pulp softening, and ascorbate biosynthesis. The initiation of ripening was cultivar specific, with faster initiation being particularly linked to the 1-aminocyclopropane-1-carboxylate oxidase and 4-alpha glucanotransferase disproportionating enzymes. Information of this kind is fundamental to determining the optimal time for picking the fruit in order to reduce post-harvest losses, and has potential applications for breeding to improve fruit quality., (© The Author(s) 2022. Published by Oxford University Press on behalf of the Society for Experimental Biology.)