Deciphering the genetic control of innate and adaptive immune responses in pig: a combined genetic and genomic study

Improving animal robustness and resistance to pathogens by adding health criteria in selection schemes is one of the challenging objectives of the next decade. In order to better understand the genetic control of immunity in French Large White pigs, we have launched a program combining genetic and genomic studies not focussing on any particular pathogen. Animals recorded for production traits were scored for a wide range of immunity parameters three weeks after vaccination against Mycoplasma hyopneumoniae: i) total white blood cells and lymphocyte counts and proportions of various leucocyte subsets including cells harbouring IgM, γδTCR, CD4/CD8, CD16/CD2 and CD16/CD172a/MHCII, ii) innate immune response parameters (phagocytosis and in vitro production of IL1B, IL6, IL8, TNF, IL12 and IFNαafter blood stimulation), iii) adaptive immune response parameters (lymphocyte proliferation, in vitro production of IL2, IL4, IL10 and IFNγ after blood stimulation, total IgG, IgA, IgM and specific IgG levels) and iv) two acute phase proteins (C-reactive protein and haploglobin). Across traits, heritability estimates reached 0.4 on average (se=0.1) and 42 of the 54 measured parameters showed moderate to high heritabilities (≥0.2), confirming that many parameters are under genetic control and could be included in selection protocols. Functional analyses revealed that the blood transcriptome is informative for part of the immunity traits and should provide relevant phenotypic information to better characterize some immunity traits

Immunity Traits in Pigs: Substantial Genetic Variation and Limited Covariation

BACKGROUND: Increasing robustness via improvement of resistance to pathogens is a major selection objective in livestock breeding. As resistance traits are difficult or impossible to measure directly, potential indirect criteria are measures of immune traits (ITs). Our underlying hypothesis is that levels of ITs with no focus on specific pathogens define an individual's immunocompetence and thus predict response to pathogens in general. Since variation in ITs depends on genetic, environmental and probably epigenetic factors, our aim was to estimate the relative importance of genetics. In this report, we present a large genetic survey of innate and adaptive ITs in pig families bred in the same environment. METHODOLOGY/PRINCIPAL FINDINGS: Fifty four ITs were studied on 443 Large White pigs vaccinated against Mycoplasma hyopneumoniae and analyzed by combining a principal component analysis (PCA) and genetic parameter estimation. ITs include specific and non specific antibodies, seric inflammatory proteins, cell subsets by hemogram and flow cytometry, ex vivo production of cytokines (IFNα, TNFα, IL6, IL8, IL12, IFNγ, IL2, IL4, IL10), phagocytosis and lymphocyte proliferation. While six ITs had heritabilities that were weak or not significantly different from zero, 18 and 30 ITs had moderate (0.1<h2≤0.4) or high (h2>0.4) heritability values, respectively. Phenotypic and genetic correlations between ITs were weak except for a few traits that mostly include cell subsets. PCA revealed no cluster of innate or adaptive ITs. CONCLUSIONS/SIGNIFICANCE: Our results demonstrate that variation in many innate and adaptive ITs is genetically controlled in swine, as already reported for a smaller number of traits by other laboratories. A limited redundancy of the traits was also observed confirming the high degree of complementarity between innate and adaptive ITs. Our data provide a genetic framework for choosing ITs to be included as selection criteria in multitrait selection programmes that aim to improve both production and health traits

GROWTH AND RAMAN ANALYSIS OF SILICON AND GERMANIUM NANOWIRES

International audienc

Raman analysis of gold catalyst vapor liquid solid germanium nanowires

International audienc

Raman analysis of gold catalyst vapor liquid solid germanium nanowires

International audienc

Croissance et caractérisation raman de nanofils de germanium

National audienceLa croissance de nanofils de germanium, synthétisés par la méthode VLS utilisant l’or comme catalyseur et le germanium comme précurseur, est étudiée pour des températures de croissance comprises en 250 °C et 400 °C. Les résultats montrent que la croissance des nanofils monocristallin a lieu pour des températures comprises entre 260°C et 370 °C. La longueur moyenne et le diamètre moyen des nanofils augmentent avec la température de croissance respectivement jusqu’à 320°C et 345 °C, puis diminuent pour des températures supérieures. Par ailleurs, à basse température (260°C et 270 °C) les nanofils sont cylindriques, alors que pour des températures supérieures ils sont de forme conique. L’analyse par spectroscopie Raman de nanofils de germanium synthétisés à 320°C de forme conique (fig. 1) montre une intensité du spectre plus importante que pour une référence monocristalline de germanium (100). De plus, des oscillations apparaissent dans le profil d’intensité (fig. 2), cette dernière croit de la base vers la pointe alors que le volume excité diminue. Ces effets peuvent être expliqués par les modes optiques apparaissant localement (rayon incident et diffusée-Raman) selon le diamètre, la longueur d’onde et le substrat (sur lequel les nanofils sont transférés après la croissance). Ces résultats expérimentaux sont prédits à partir de simulations théoriques

Raman analysis of gold catalyst vapor liquid solid germanium nanowires

International audienceGermanium nanowires (GeNWs) were synthesized in alow pressure chemical vapor deposition reactor (LPCVD)using a vapor-liquid-solid process (VLS). In this work,the focus is put on the characterization of these GeNWsusing scanning electron microscopy (SEM) combinedwith Raman spectroscopy. In particular, NWs with conicalshape grown at a moderate temperature (320 °C) wereinvestigated in terms of the intensity measured for theGe-related Raman line. The two main observations, discussedin this paper, are the anomalous magnitude of thisline, as compared to measurements under the same conditionson a Ge(100) substrate, and the oscillations observedwhen the Raman line intensity is measured whilescanning the laser beam along the axis of the conicalshaped NWs, from the tip to the bottom. These effectsare discussed involving the fact that optical modes appearin such NWs (both for the incident and Raman scatteredlight) when conditions on the diameter, the laser excitationwavelength, and substrate (on which the NWs aretransferred after growth) are fulfilled. Taking into accountthese specific optical modes, the effects observedcan be explained