Project description:The human intestinal microbiota associated with rats produces in vivo a soluble(s) factor(s) that down-regulates the expression of genes encoding for the Shiga toxin II in E. coli O157:H7. The Shiga toxin II is one of the major virulence factors of E. coli enterohemorragic leading to the deadly hemolitic and uremic syndrome. Investigation of the effect of the human intestinal microbiota on the whole transcriptome of EHEC O157:H7 is of major importance to increase our understanding of the pathogen transcriptomic adaptation in response to the human microbiota. We analysed by microarray hybridization the gene expression pattern of EHEC O157:H7 grown in the caecal content of germ-free rats or rats associated with the human microbiota of a healthy human subject. By doing so, we increased our understanding of the regulatory activities of the human gut microbiota on E. coli O157:H7 A first group of twelve weeks old, male, germfree rats was colonized with the human fecal microbiota and a second group was kept germfree and condidered as a controle group. Rats were fed for two weeks with a sterile human type diet, and were sacrificed. E. coli O157:H7 was cultivated for 6 hours in the caecal content of germfree rats and rats associated with the human intestinal microbiota. RNAs were extracted and cDNAs were synthesized, fragmented and biotinylated before being hybridized on Affymetrix E. coli genome 2.0 arrays. The effect of the human intestinal microbiota was investigated by comparing the gene expression level in the caecal content of rats associated with the human microbiota with their expression level in the caecal content of the germfree rats.
Project description:The human intestinal microbiota associated with rats produces in vivo a soluble(s) factor(s) that down-regulates the expression of genes encoding for the Shiga toxin II in E. coli O157:H7. The Shiga toxin II is one of the major virulence factors of E. coli enterohemorragic leading to the deadly hemolitic and uremic syndrome. Investigation of the effect of the human intestinal microbiota on the whole transcriptome of EHEC O157:H7 is of major importance to increase our understanding of the pathogen transcriptomic adaptation in response to the human microbiota. We analysed by microarray hybridization the gene expression pattern of EHEC O157:H7 grown in the caecal content of germ-free rats or rats associated with the human microbiota of a healthy human subject. By doing so, we increased our understanding of the regulatory activities of the human gut microbiota on E. coli O157:H7
Project description:Genetic (animal species, breed and genotype) has a considerable effect on milk composition. In particular, goats present a remarkable polymorphism at the alpha-S1-casein (CSN1S1) locus which results in large differences in milk protein content and indirectly in milk fat content and its fatty acids composition. In order to decipher the mammary metabolic pathways involved, we examined the effect of CSN1S1 polymorphism on the expression of 8,379 genes in caprine mammary gland using a bovine oligonucleotide microarray. Six lactating goats fed ad libitum were assigned to 2 groups based on their genotype at the CSN1S1 locus: High vs. Low genotype goats carrying, respectively, two reference alleles associated with high CSN1S1 synthesis and two defective alleles associated with low CSN1S1 synthesis. Keywords: Genotype comparison
Project description:Genetic (animal species, breed and genotype) has a considerable effect on milk composition. In particular, goats present a remarkable polymorphism at the alpha-S1-casein (CSN1S1) locus which results in large differences in milk protein content and indirectly in milk fat content and its fatty acids composition. In order to decipher the mammary metabolic pathways involved, we examined the effect of CSN1S1 polymorphism on the expression of 8,379 genes in caprine mammary gland using a bovine oligonucleotide microarray. Six 48-h food-deprived lactating goats were assigned to 2 groups based on their genotype at the CSN1S1 locus: High vs. Low genotype goats carrying, respectively, two reference alleles associated with high CSN1S1 synthesis and two defective alleles associated with low CSN1S1 synthesis. Keywords: Genotype comparison