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Bisphenol s impaired in vitro ovine early developmental oocyte competence
No full textIntroduction: Bisphenol A (BPA) is a widespread compound in the plastic industry that is especially used to produce baby bottles, food packaging and metal cans. BPA, an endocrine disruptor, leads to alterations in reproductive function and therefore has been banned from the food industry. Unregulated BPA analogues, particularly Bisphenol S (BPS), have emerged and are now used in the plastic industry. Thus, this study aimed to examine the acute effects of low and environmental doses of BPS on ewe oocyte quality and developmental competence, and its mechanism of action, during in vitro maturation. Methods: Ewe cumulus-oocyte complexes underwent in vitro maturation in the presence or absence of BPS (1 nM, 10 nM, 100 nM, 1 μM or 10 μM). Oocytes were then subjected to in vitro fertilisation and development. Results:1 μM BPS induced a 12.7% decrease in the cleavage rate (p= 0.004) and a 42.6% decrease in the blastocyst rate (p= 0.017) compared to control. The blastocyst rate reduction was also observed with 10 nM BPS. Furthermore, 10 μM BPS reduced the oocyte maturation rate,and 1 μM BPS decreased cumulus cell progesterone secretion. PRand AMHgene expression were reduced in cumulus cells. BPS induced a 5-fold increase in MAPK 3/1 activation (p= 0.04). Conclusions:BPS impaired ewe oocyte developmental competence. The data suggest that BPS might not be a safe BPA analogue. Further studies are required to elucidate its detailed mechanism of actio
Trehalose Synthesis Contributes to Osmotic Stress Tolerance and Virulence of the Bacterial Wilt Pathogen Ralstonia solanacearum
No full textThe xylem-dwelling plant pathogen Ralstonia solanacearum changes the chemical composition of host xylem sap during bacterial wilt disease. The disaccharide trehalose, implicated in stress tolerance across all kingdoms of life, is enriched in sap from R. solanacearum–infected tomato plants. Trehalose in xylem sap could be synthesized by the bacterium, the plant, or both. To investigate the source and role of trehalose metabolism during wilt disease, we evaluated the effects of deleting the three trehalose synthesis pathways in the pathogen: TreYZ, TreS, and OtsAB, as well as its sole trehalase, TreA. A quadruple treY/treS/otsA/treA mutant produced 30-fold less intracellular trehalose than the wild-type strain missing the trehalase enzyme. This trehalose-nonproducing mutant had reduced tolerance to osmotic stress, which the bacterium likely experiences in plant xylem vessels. Following naturalistic soil-soak inoculation of tomato plants, this triple mutant did not cause disease as well as wild-type R. solanacearum. Further, the wild-type strain out-competed the trehalose-nonproducing mutant by over 600-fold when tomato plants were coinoculated with both strains, showing that trehalose biosynthesis helps R. solanacearum overcome environmental stresses during infection. An otsA (trehalose-6-phosphate synthase) single mutant behaved similarly to ΔtreY/treS/otsA in all experimental settings, suggesting that the OtsAB pathway is the dominant trehalose synthesis pathway in R. solanacearum
Forest management in southern China generates short term extensive carbon sequestration
No full textLand use policies have turned southern China into one of the most intensively managed forest regions in the world, with actions maximizing forest cover on soils with marginal agricultural potential while concurrently increasing livelihoods and mitigating climate change. Based on satellite observations, here we show that diverse land use changes in southern China have increased standing aboveground carbon stocks by 0.11 ± 0.05 Pg C y−1 during 2002–2017. Most of this regional carbon sink was contributed by newly established forests (32%), while forests already existing contributed 24%. Forest growth in harvested forest areas contributed 16% and non-forest areas contributed 28% to the carbon sink, while timber harvest was tripled. Soil moisture declined significantly in 8% of the area. We demonstrate that land management in southern China has been removing an amount of carbon equivalent to 33% of regional fossil CO2 emissions during the last 6 years, but forest growth saturation, land competition for food production and soil-water depletion challenge the longevity of this carbon sink service
Genomic footprints of recovery in the European bison
No full textAfter extinction in the wild in the beginning of the twentieth century, the European bison has been successfully recovered in two distinct genetic lines from only twelve and seven captive founders. We here aimed at characterizing the levels of realized inbreeding in these two restored lines to provide empirical insights into the genomic footprints left by population recovery from a small number of founders. To that end, we genotyped 183 European bison born over the last 40 years with the Illumina BovineHD beadchip that contained 22,602 informative autosomal SNPs after data filtering. We then identified homozygous-by-descent (HBD) segments and classified them into different age-related classes relying on a model-based approach. As expected, we observed that the strong and recent founder effect experienced by the two lines resulted in very high levels of recent inbreeding and in the presence of long HBD tracks (up to 120 Mb). These long HBD tracks were associated with ancestors living approximately from 4 to 32 generations in the past suggesting that inbreeding accumulated over multiple generations after the bottleneck. The contribution to inbreeding of the most recent groups of ancestors were however found to be decreasing in both lines. In addition, comparison of Lowland individuals born at different time periods showed that the levels of inbreeding tended to stabilize, HBD segments being shorter in animals born more recently which indicates efficient control of inbreeding. Monitoring HBD segment lengths over generations may thus be viewed as a valuable genomic diagnostic tool for populations in conservation or recovery programs
Avian uterine fluid proteome: exosomes and biological processes potentially involved in sperm survival
No full textUterine fluid is an aqueous milieu to which sperm are exposed during their storage and ascent. In this study a bottom up proteomic strategy and bioinformatic analysis of hen uterine fluid was performed to improve understanding of this fluid and its potential role in sperm survival mechanisms. The proteomic data were submitted to ProteomeXchange. Among the 913 proteins identified, 160 are known to be secreted and 640 are referenced in exosomes databases. We isolated exosomes from avian uterine fluid, analyzed them using electron microscopy and targeted several exosomes markers (ANXA1/2/4/5, VCP, HSP90A, HSPA8, PARK7, and MDH1) using immunoblotting. Electron microscopy and immunohistochemistry were also used to analyze uterovaginal junctions for the exosomal proteins ANXA4, VCP and PARK7. Exosomes were observed both at the surface epithelium and inside sperm storage tubules. Our data were compared to two previously published studies on proteomic of hen uterine fluid, and with one study describing the proteomic content of rooster seminal plasma and sperm. In conclusion, we demonstrated for the first time that avian uterine fluid contains exosomes. These may play a key role in preserving sperm functions within the female genital tract. Their presence in the sperm storage tubules may represent an important mechanism regarding interaction between the female genital tract and sperm
How effective are strategies to control the dissemination of antibiotic resistance in the environment? A systematic review
No full textBackground: Antibiotic resistance is a major concern for public and environmental health. The role played by the environment in disseminating resistance is increasingly considered, as well as its capacity for mitigation. We reviewed the literature on strategies to control dissemination of antibiotic-resistant bacteria (ARB), antibiotic resistance genes (ARG) and mobile genetic elements (MGE) in the environment.
Methods: This systematic review focused on three main strategies: (i) restriction of antibiotic use (S1), (ii) treatments of liquid/solid matrices (S2) and (iii) management of natural environment (S3). Articles were collected from seven scientific databases until July 2017 and from Web of Science until June 2018. Only studies reporting measurements of ARB, ARG or MGE in environmental samples were included. An evidence map was drawn from metadata extracted from all studies eligible for S1, S2 and S3. Subsets of studies were assessed for internal and external validity to perform narrative and quantitative syntheses. A meta-analysis was carried out to assess the effects of organic waste treatments (random-effect models).
Review findings: Nine hundred and thirty-one articles representing 1316 individual studies (n) were eligible for S1 (n = 59), S2 (n = 781) and S3 (n = 476) strategies, respectively. Effects of interventions to control the dissemination of antibiotic resistance in the environment were primarily studied in strategy S2. A partial efficiency of wastewater treatment plants (WWTPs) to reduce antibiotic resistance in treated effluent was reported in 118 high validity studies. In spite of the heterogeneity in published results, the meta-analysis showed that composting and drying were efficient treatments to reduce the relative abundance of ARG and MGE in organic waste, by 84% [65%; 93%] and 98% [80%; 100%], respectively. The effect of anaerobic digestion was not statistically significant (51% reduction [− 2%; 77%]) when organic waste treatments were compared together in the same model. Studies in strategies S1 and S3 mainly assessed the effects of exposure to sources of contamination. For instance, 28 medium/high validity studies showed an increase of antibiotic resistance in aquatic environments at the WWTP discharge point. Some of these studies also showed a decrease of resistance as the distance from the WWTP increases, related to a natural resilience capacity of aquatic environments. Concerning wildlife, nine medium/high validity studies showed that animals exposed to anthropogenic activities carried more ARB.
Conclusions and implications : Knowledge gaps were identified for the relationship between restriction of antibiotic use and variation of antibiotic resistance in the environment, as well as on possible interventions in situ in natural environment. Organic waste treatments with thermophilic phase (> 50 °C) should be implemented before the use/release of organic waste in the environment. More investigation should be conducted with the datasets available in this review to determine the treatment efficiency on ARG carried by specific bacterial communities
Machine learning to detect behavioural anomalies in dairy cows under subacute ruminal acidosis
No full textImportance du phénotypage pour maintenir la précision des prédictions génomiques des caractères mesurés en station
No full textGenomic evaluation of French maternal lines, set up in 2016, has helped increase genetic progress, especially for reproductive traits. However, computational problems have emerged for genomic evaluation of certain production traits for which phenotyping capacity is limited. This particularly concerns genotyped candidates on breeding farms that have no phenotypes and only a few phenotyped relatives. This data structure seems to pose convergence problems for predicting genomic breeding values. To check this hypothesis, we simulated such a situation, based on a set of actual phenotype data measured for all farm candidates and genotypes. The simulation consisted of deleting phenotypes of the animals measured on-farm in order to reproduce the data structure encountered for the traits recorded at the FGPorc/INRAE test station in Le Rheu. Phenotypes were then progressively added in different scenarios to identify whether prediction accuracy improved and to estimate the number of phenotypes required. The simulations showed that the unbalanced structure between genotypes and phenotypes was responsible for the computational problems that led to low accuracy of genomic predictions. Phenotyping 12% of all pigs phenotyped at 100 kg each year made it possible to solve the computational problems observed and to recover 61% of the maximum expected accuracy. In conclusion, these results highlight the importance of collecting large-scale phenotypes in the context of genomic selection schemes. Further studies will be conducted to study the impact of genotyping animals measured at the station
The Value of Public Information in Storable Commodity Markets: Application to the Soybean Market
No full textThis article provides a framework to estimate the potential effects and benefits of the provision of market information in storable commodity markets. This framework is applied to the case of production forecasts for the soybean market. A rational expectations storage model of the global soybean market accounting for both inter-annual and intra-annual market dynamics is built. Shocks that occur between planting and harvesting affect the size of the potential harvest. Estimates of the size of these shocks are reported publicly, and affect the market equilibrium through adjustments to stock levels. By varying counterfactually the observability of seasonal shocks, we can estimate the efficiency gains related to the availability of advance information. They are equivalent to 2% of storage costs; the reduction of stock levels being the main channel explaining the welfare gains. The presence of advance information has a limited effect on inter-annual price volatility but redistributes price volatility during the season, increasing it just before harvest when almost all news has been received and stocks are tight, and decreasing it after harvest. The effect of news shocks is stronger on higher-order moments of the distribution with a strong decrease in skewness and kurtosis related to the lower frequency of price spikes.Cet article propose un cadre d'analyse des effets potentiels et des bénéfices de la fourniture d'information de marché dans les marchés de matières premières stockables. Ce cadre est appliqué au cas des prévisions de production pour le marché du soja. Un modèle de stockage à anticipations rationnelles du marché mondial du soja prenant en compte à la fois les dynamique intra- et inter-annuelles est construit. Des chocs arrivant entre les semis et la récolte affectent la taille de la récolte potentielle. Des estimations de la taille de ces chocs sont rendues publiques et affectent l'équilibre de marché via l'ajustement des niveaux de stocks. En variant l'observabilité des chocs, nous pouvons estimer les gains d'efficiences en lien avec la disponibilité de l'information. Ils sont équivalents à 2% des coûts de stockage; la réduction des niveaux de stocks étant la principale explication des gains de bien-être. La présence d'information avant la récolte a un effet limité sur la volatilité des prix inter-annuelle mais redistribue la volatilité des prix durant la saison, l'augmentant juste avant la récolte lorsque presque toute les nouvelles ont été reçues et les stocks sont limités, et la diminuant après la récolte. L'effet des chocs de nouvelles est plus important sur les moments d'ordre élevé avec une forte décroissance de l’asymétrie et du kurtosis en lien avec la plus faible fréquence des pics de prix