Whole blood transcriptome profiles of trypanotolerant and trypanosusceptible cattle highlight a differential modulation of metabolism and immune response during infection by Trypanosoma congolense

Animal African trypanosomosis, caused by blood protozoan parasites transmitted mainly by tsetse flies, represents a major constraint for millions of cattle in sub-Saharan Africa. Exposed cattle include trypanosusceptible indicine breeds, severely affected by the disease, and West African taurine breeds called trypanotolerant owing to their ability to control parasite development, survive and grow in enzootic areas. Until now the genetic basis of trypanotolerance remains unclear. Here, to improve knowledge of the biological processes involved in trypanotolerance versus trypanosusceptibility, we identified bovine genes differentially expressed in five West African cattle breeds during an experimental infection by Trypanosoma congolense and their biological functions. To this end, whole blood genome-wide transcriptome of three trypanotolerant taurine breeds (N’Dama, Lagune and Baoulé), one susceptible zebu (Zebu Fulani) and one African taurine x zebu admixed breed (Borgou) were profiled by RNA sequencing at four time points, one before and three during infection. As expected, infection had a major impact on cattle blood transcriptome regardless of the breed. The functional analysis of differentially expressed genes over time in each breed confirmed an early activation of the innate immune response, followed by an activation of the humoral response and an inhibition of T cell functions at the chronic stage of infection. More importantly, we highlighted overlooked features, such as a strong disturbance in host metabolism and cellular energy production that differentiates trypanotolerant and trypanosusceptible breeds. N’Dama breed showed the earliest regulation of immune response, associated with a strong activation of cellular energy production, also observed in Lagune, and to a lesser extent in Baoulé. Susceptible Zebu Fulani breed differed from other breeds by the strongest modification in lipid metabolism regulation. Overall, this study provides a better understanding of the biological mechanisms at work during infection, especially concerning the interplay between immunity and metabolism that seems differentially regulated depending on the cattle breeds

A Quasi-Exclusive European Ancestry in the Senepol Tropical Cattle Breed Highlights the Importance of the slick Locus in Tropical Adaptation

Background: The Senepol cattle breed (SEN) was created in the early XXth century from a presumed cross between a European (EUT) breed (Red Poll) and a West African taurine (AFT) breed (N'Dama). Well adapted to tropical conditions, it is also believed trypanotolerant according to its putative AFT ancestry. However, such origins needed to be verified to define relevant husbandry practices and the genetic background underlying such adaptation needed to be characterized. Methodology/Principal Findings: We genotyped 153 SEN individuals on 47,365 SNPs and combined the resulting data with those available on 18 other populations representative of EUT, AFT and Zebu (ZEB) cattle. We found on average 89% EUT, 10.4% ZEB and 0.6% AFT ancestries in the SEN genome. We further looked for footprints of recent selection using standard tests based on the extent of haplotype homozygosity. We underlined i) three footprints on chromosome (BTA) 01, two of which are within or close to the polled locus underlying the absence of horns and ii) one footprint on BTA20 within the slick hair coat locus, involved in thermotolerance. Annotation of these regions allowed us to propose three candidate genes to explain the observed signals (TIAM1, GRIK1 and RAI14). Conclusions/Significance: Our results do not support the accepted concept about the AFT origin of SEN breed. Initial AFT ancestry (if any) might have been counter-selected in early generations due to breeding objectives oriented in particular toward meat production and hornless phenotype. Therefore, SEN animals are likely susceptible to African trypanosomes which questions the importation of SEN within the West African tsetse belt, as promoted by some breeding societies. Besides, our results revealed that SEN breed is predominantly a EUT breed well adapted to tropical conditions and confirmed the importance in thermotolerance of the slick locus. (Résumé d'auteur

Non-Standard Errors

In statistics, samples are drawn from a population in a data-generating process (DGP). Standard errors measure the uncertainty in estimates of population parameters. In science, evidence is generated to test hypotheses in an evidence-generating process (EGP). We claim that EGP variation across researchers adds uncertainty: Non-standard errors (NSEs). We study NSEs by letting 164 teams test the same hypotheses on the same data. NSEs turn out to be sizable, but smaller for better reproducible or higher rated research. Adding peer-review stages reduces NSEs. We further find that this type of uncertainty is underestimated by participants

Elaboration d'un portfolio dans le cadre du diplôme d'études spécialisées de médecine générale à Lyon

Dans le cadre du Diplôme d'Études Spécialisées (DES) de médecine générale à Lyon, le tutorat est un choix pédagogique centré sur l'apprenant et ses apprentissages, dont l'objectif est de certifier qu'un interne en fin de DES est un professionnel compétent. Le carnet de bord est un outil pédagogique qui doit aider à cette certification en rendant compte de tout le travail accompli et de la progression de l'interne durant ses trois années de DES. Or, l utilisation du carnet de bord dans notre faculté est un échec. Les travaux réalisés sur le ressenti des internes au sujet de cet outil sont unanimes: il n'est pas apprécié et mal exploité. Proposer une nouvelle version du carnet de bord, adaptée et pertinente. Pour émettre les propositions de réforme du carnet de bord, rapidement renommé portfolio, nous avons: - effectué des recherches documentaires afin d'établir un état des lieux des portfolios des autres facultés ; -effectué des recherches bibliographiques de pédagogie et d'éducation médicales ; - participé à des réunions avec les tuteurs, les enseignants et les internes. Nous avons mis en place sur support informatique sept rubriques distinctes: la première pour permettre à l'interne de comprendre ce qui est attendu de lui grâce aux tutoriels (le Guide du portfolio, le Guide pratique de l'interne, le Carnet de compétences); les six autres sont à renseigner par l'interne durant les trois années de DES (Journaux de stage, GEP, Bibliothèque de recherches personnelles, Mémento, Thèse - Mémoire de recherche, et la rubrique de synthèse Compétences enrichies - Mémoire de DES). Les tuteurs et les internes vont devoir s'approprier l'outil, que nous avons tenté de rendre le plus didactique possible. Ce nouveau portfolio, baptisé Portfolyon, n'est que le commencement dans la volonté du DMG de le faire évoluer afin qu'il soit le plus performant possible. Les prochaines étapes seront son évaluation et la mise en place d'une version en ligneLYON1-BU Santé (693882101) / SudocSudocFranceF

Les étudiants en médecine (entre accomplissement et épuisement)

LYON1-BU Santé (693882101) / SudocPARIS-BIUM (751062103) / SudocSudocFranceF

Adaptation of tropical cattle breeds to their environment, in the perspective of climatic change

Cattle breeds may be broadly divided between temperate taurine breeds, from European origins, African taurine breeds, and Indian zebu breeds, and various admixed populations. A little number of these breeds has a world-wide distribution, while many of them have evolved in restrained area and remain at a local or a regional level. Tropical countries are rich of a wide diversity of original cattle breeds, which characteristics remain mostly undescribed. These characteristics are the results of various forces, like the genetic background of the ancestral populations, the influence of agro ecological environment in which they have evolved, and the livestock keeper preferences and practices. Tropical cattle breeds have therefore develop specific attributes and functions, to adapt to a wide range of environmental constraints and production systems. Such characteristics are the ability to tolerate high ambient temperature, with a reduce effect on their production skills, resistance to internal or external parasites and infectious diseases, valorization of rough diets, tolerance to harsh conditions and ability to recuperate in more favorable seasons, and working ability. These characteristics may be in the future of a great utility to face the deleterious effects of climate change. The physiological traits involved in these characteristics are complex and their genetic basis has not yet been unraveled. However some studies of selection signatures identification give some insights on the genetic background of some adaptation traits of local tropical cattle breeds that could be useful in the future to face the direct and indirect effects of climatic change on livestock production systems