Agrocampus Ouest

About: Agrocampus Ouest is a education organization based out in Rennes, France. It is known for research contribution in the topics: Population & Soil water. The organization has 2160 authors who have published 3219 publications receiving 75606 citations. The organization is also known as: Institut supérieur des sciences agronomiques, agroalimentaires, horticoles et du paysage & Higher Institute for agricultural sciences, food industry, horticulture and landscape management.

Extending in vitro digestion models to specific human populations: Perspectives, practical tools and bio-relevant information

Abstract: Background In vitro digestion models show great promise in facilitating the rationale design of foods. This paper provides a look into the current state of the art and outlines possible future paths for developments of digestion models recreating the diverse physiological conditions of specific groups of the human population. Scope and approach Based on a collective effort of experts, this paper outlines considerations and parameters needed for development of new in vitro digestion models, e.g. gastric pH, enzymatic activities, gastric emptying rate and more. These and other parameters are detrimental to the adequate development of in vitro models that enable deeper insight into matters of food luminal breakdown as well as nutrient and nutraceutical bioaccessibility. Subsequently, we present an overview of some new and emerging in vitro digestion models mirroring the gastro-intestinal conditions of infants, the elderly and patients of cystic fibrosis or gastric bypass surgery. Key findings and conclusions This paper calls for synchronization, harmonization and validation of potential developments in in vitro digestion models that would greatly facilitate manufacturing of foods tailored or even personalized, to a certain extent, to various strata of the human population.

Relationships between colostrum production by primiparous sows and sow physiology around parturition.

Abstract: Relationships between hormonal and metabolic changes around parturition and colostrum yield and composition were investigated in 16 Landrace x Large White primiparous sows. Blood samples were taken daily from d 105 of pregnancy to d 2 postpartum (with d 0 being the day of parturition). Colostrum samples were taken at the onset of parturition (T0), and then 3, 6, and 24 h later (T3, T6, and T24, respectively). Colostrum yield was calculated from the beginning of parturition until 24 h later by adding colostrum intake of individual piglets, which was estimated from their BW gain. Colostrum yield averaged 3.22 +/- 0.34 kg. Four sows had very low colostrum production (1.10 +/- 0.12 kg; n = 4), whereas the others produced between 2.83 and 4.64 kg of colostrum (3.93 +/- 0.16 kg; n = 12). Compared with the high-colostrum-producing sows, the low-colostrum-producing sows tended (P 0.1) was found between IgG concentrations in colostrum at any time and prolactin, estradiol-17beta, progesterone, or cortisol. In conclusion, sows that produced a low yield of colostrum were characterized by a leaky mammary epithelium and reduced synthesis of lactose, related to delayed hormonal changes before parturition.

Bayesian QTL analyses using pedigreed families of an outcrossing species, with application to fruit firmness in apple

Abstract: Bayesian QTL linkage mapping approaches offer the flexibility to study multiple full sib families with known pedigrees simultaneously. Such a joint analysis increases the probability of detecting these quantitative trait loci (QTL) and provide insight of the magnitude of QTL across different genetic backgrounds. Here, we present an improved Bayesian multi-QTL pedigree-based approach on an outcrossing species using progenies with different (complex) genetic relationships. Different modeling assumptions were studied in the QTL analyses, i.e., the a priori expected number of QTL varied and polygenic effects were considered. The inferences include number of QTL, additive QTL effect sizes and supporting credible intervals, posterior probabilities of QTL genotypes for all individuals in the dataset, and QTL-based as well as genome-wide breeding values. All these features have been implemented in the FlexQTL™ software. We analyzed fruit firmness in a large apple dataset that comprised 1,347 individuals forming 27 full sib families and their known ancestral pedigrees, with genotypes for 87 SSR markers on 17 chromosomes. We report strong or positive evidence for 14 QTL for fruit firmness on eight chromosomes, validating our approach as several of these QTL were reported previously, though dispersed over a series of studies based on single mapping populations. Interpretation of linked QTL was possible via individuals’ QTL genotypes. The correlation between the genomic breeding values and phenotypes was on average 90 %, but varied with the number of detected QTL in a family. The detailed posterior knowledge on QTL of potential parents is critical for the efficiency of marker-assisted breeding.

Cell surface polysaccharides of Bifidobacterium bifidum induce the generation of Foxp3+ regulatory T cells

Abstract: Dysregulation of intestinal microflora is linked to inflammatory disorders associated with compromised immunosuppressive functions of Foxp3+ T regulatory (Treg) cells. Although mucosa-associated commensal microbiota has been implicated in Treg generation, molecular identities of the “effector” components controlling this process remain largely unknown. Here, we have defined Bifidobacterium bifidum as a potent inducer of Foxp3+ Treg cells with diverse T cell receptor specificity to dietary antigens, commensal bacteria, and B. bifidum itself. Cell surface β-glucan/galactan (CSGG) polysaccharides of B. bifidum were identified as key components responsible for Treg induction. CSGG efficiently recapitulated the activity of whole bacteria and acted via regulatory dendritic cells through a partially Toll-like receptor 2–mediated mechanism. Treg cells induced by B. bifidum or purified CSGG display stable and robust suppressive capacity toward experimental colitis. By identifying CSGG as a functional component of Treg-inducing bacteria, our studies highlight the immunomodulatory potential of CSGG and CSGG-producing microbes.

Measuring Genetic Differentiation from Pool-seq Data.

Abstract: The advent of high throughput sequencing and genotyping technologies enables the comparison of patterns of polymorphisms at a very large number of markers. While the characterization of genetic structure from individual sequencing data remains expensive for many nonmodel species, it has been shown that sequencing pools of individual DNAs (Pool-seq) represents an attractive and cost-effective alternative. However, analyzing sequence read counts from a DNA pool instead of individual genotypes raises statistical challenges in deriving correct estimates of genetic differentiation. In this article, we provide a method-of-moments estimator of F-ST for Pool-seq data, based on an analysis-of-variance framework. We show, by means of simulations, that this new estimator is unbiased and outperforms previously proposed estimators. We evaluate the robustness of our estimator to model misspecification, such as sequencing errors and uneven contributions of individual DNAs to the pools. Finally, by reanalyzing published Pool-seq data of different ecotypes of the prickly sculpin Cottus asper, we show how the use of an unbiased F-ST estimator may question the interpretation of population structure inferred from previous analyses.