Volailles axéniques : des modèles originaux pour l'étude du microbiote

Résumé de la communication présentée lors du 42ème Congrès de l'AFSTAL en octobre 2016 à NantesVolailles axéniques : des modèles originaux pour l'étude du microbiot

Volailles axéniques : des modèles originaux pour l'étude du microbiote

Session 4 : Facteurs influentsNational audienc

Équipe expérimentale : Étude des processus infectieux en confinement A1à A3 sur les animaux de rente, de laboratoire, de loisir et de la faune sauvage

Présentation du poster en 180 sec de l'activité des équipes expérimentation / élevage de la PFIENational audienc

Functional investigation of the human oocyte-expressed gene bcar4 using domestic animal models and genome editing.

National audienceWe have previously characterized BCAR4 (Breast Cancer Anti-estrogen Resistant 4) as a gene preferentially expressed in human oocytes as compared to ovarian somatic cells or non-pathologic non-reproductive tissues. BCAR4 is conserved in primates and in various domestic species such as cow, pig, dog, horse or rabbit, but it is not found in the genome of rodents. This pattern coincides with a delayed major activation of the embryonic genome, i.e. after several cleavages. BCAR4 is also an oncogene overexpressed in a subset of breast tumors and other cancers. Altogether, the restricted expression, proliferative properties and phylogeny suggested that BCAR4 may be involved in early embryonic divisions.We have analyzed BCAR4 expression in the cow. While RNA is already transcribed in the oocyte of preovulatory follicles, protein synthesis is delayed until late maturation, peaks in early cleaving embryos, persists until the morula stage to become undetectable in blastocysts. Microinjecting BCAR4-targeting small-interfering RNA significantly decreased BCAR4 expression and compromised in vitro blastocyst development, demonstrating that BCAR4 is a maternal-effect gene.To investigate BCAR4 function in vivo, the rabbit model was chosen for genome editing. Rabbits carrying an altered BCAR4 gene were produced using a transcription activator-like effector nuclease (TALEN). Wild-type, heterozygous and homozygous carrier animals were born following the expected mendelian ratio. They were viable and appeared healthy, as expected for animals with an altered maternal effect-gene. Efficiency of the genetic alteration was evaluated by reverse-transcription coupled to PCR. It showed that BCAR4 RNA expression was abolished in follicles from homozygous carriers as compared to their heterozygous and wild-type littermates. These females will be phenotyped onto various reproductive parameters to assess the role of BCAR4 in fertility in vivo

Influence du microbiote intestinal initial sur les comportements émotionnels de la caille japonaise (Coturnix japonica)

Influence du microbiote intestinal initial sur les comportements émotionnels de la caille japonaise (Coturnix japonica). 47. Colloque Annuel de la Société Française pour l’Etude du Comportement Anima

In ovo administration of a phage cocktail partially prevents colibacillosis in chicks

ABSTRACT: Avian pathogenic Escherichia coli (APEC) causes colibacillosis, the main bacterial disease in poultry leading to significant economic losses worldwide. Antibiotic treatments favor the emergence of multidrug-resistant bacteria, and preventive measures are insufficient to control the disease. There is increasing interest in using the potential of bacteriophages, not only for phage therapy but also for prevention and biocontrol. This study aimed to evaluate the efficacy of a phage cocktail administered in ovo to prevent avian colibacillosis in chicks. When 4 different phages (REC, ESCO3, ESCO47, and ESCO58), stable under avian physiological conditions, were combined and inoculated at 17 embryogenic days (ED), they were transmitted to the newly hatched chicks. In a second trial, the 4-phage cocktail was inoculated into the allantoic fluid at ED16 and after hatch 1-day-old chicks were challenged with the O2 APEC strain BEN4358 inoculated subcutaneously. Two phages (REC and ESCO3) were still detected in the ceca of surviving chicks at the end of the experiment (7-days postinfection). Chicks that received the phages in ovo did not develop colibacillosis lesions and showed a significant decrease in intestinal BEN4358 load (8.00 × 107 CFU/g) compared to the challenged chicks (4.52 × 108 CFU/g). The majority of the reisolated bacteria from the ceca of surviving chicks had developed full resistance to ESCO3 phage, and only 3 were resistant to REC phage. The partially or complete resistance of REC phage induced a considerable cost to bacterial virulence. Here, we showed that phages inoculated in ovo can partially prevent colibacillosis in 1-wk-old chicks. The reduction in the APEC load in the gut and the decreased virulence of some resistant isolates could also contribute to control the disease

Rôle du gène <em>BCAR4</em> dans la fertilité femelle : expression et approche fonctionnelle <em>in vivo</em> chez le lapin

National audienc

Effects of gut microbiota transfer on emotional reactivity in Japanese quails (Coturnix japonica)

International audienceThe interaction between the gut microbiota (GM) and the brain has led to the concept of the microbiota-gut-brain axis but data in birds remain scarce. We tested the hypothesis that colonization of germ-free chicks from a quail line selected for a high emotional reactivity (E+) with GM from a line with low emotional reactivity (E-) would reduce their emotional behaviour in comparison with germ-free chicks from E+ line colonized with GM from the same E+ line. The GM composition analysis of both groups revealed a shift in term of microbial diversity and richness between Day 21 and Day 35 and the GM of the two groups of quails were closer to each other at Day 35 than at Day 21 at a phylum level. Quails that received GM from the E- line expressed a lower emotional reactivity than the quails colonized by GM from the E+line in the tonic immobility and the novel environment tests proceeded during the second week of age. This result was reversed in a second tonic immobility test and an open-field run two weeks later. These behavioural and GM modifications over time could be the consequence of the resilience of the GM to recover its equilibrium present in the E+ host, which is in part driven by the host genotype. This study shows for the first time that a gut microbiota transfer can influence emotional reactivity in Japanese quails strengthening the existence of a microbiota-gut-brain axis in this species of bird

BCAR4 is involved in in vitro preimplantation development: investigating its role in vivo by genome efditing in rabbit

BCAR4 is involved in [i]in vitro[/i] preimplantation development: investigating its role [i]in vivo[/i] by genome efditing in rabbit. 2. Journées du GdR 3606 Repr