Project description:Goat's alphaS1-casein (CSN1S1) polymorphism has a significant effect on milk protein and lipid composition, which affects the nutritional quality and technological properties of milk. Moreover, this polymorphism has a large impact on the morphology of mammary epithelial cells. To explore the metabolic pathways modulated in relation to this polymorphism, we compared the mammary gene expression profiles of two groups of lactating goats carrying either two reference or two defective alleles, using a bovine oligonucleotide microarray representing 8379 genes. We identified 41 differentially expressed genes between the two genotype groups. In particular, we showed a downregulation of two key lipogenic genes encoding fatty acid synthase and glycerol-3-phosphate acyltransferase in agreement with the low fat concentration associated with CSN1S1 deficiency. In addition, this study highlights changes in the expression level of several genes known to influence membrane fluidity, cell-cell interaction or chromatin organization. Our results open up new fields of investigation on structural modifications associated with CSN1S1 deficiency that could affect mammary gland function. Keywords: SuperSeries This SuperSeries is composed of the following subset Series: GSE6637: Impact of CSN1S1 polymorphism on mammary transcriptome of lactating goats GSE6642: Impact of CSN1S1 polymorphism on mammary transcriptome of food-deprived lactating goats. Refer to individual Series
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
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 6 slides were performed for a total of 3 independent comparisons (CompA, CompB, CompC): each microarray was co-hybridized with one High CSN1S1 genotype goat sample and one Low CSN1S1 genotype goat sample; each hybridization was repeated in a dye-swap manner for a total of 4 spots per oligonucleotide (2 intra- and 2 inter-slides).
Project description:Nutrition affects milk composition influencing its nutritional properties. Nutrition also modifies the expression of mammary genes, whose regulation is not completely known. MicroRNAs (miRNA) are small non-coding RNA that work as important post-transcriptional gene expression regulators by targeting messenger RNAs. Our goal was to characterize miRNA whose expression is regulated by nutrition in the lactating goat mammary gland, and which may give clues to decipher the regulations of milk components biosynthesis and secretion. Using high-throughput sequencing technology, miRNomes of the lactating mammary gland have been established from 4 goats fed ad libitum and 6 goats food deprived during 48h. Food deprivation affected the expression of 30 miRNA (padj<0.1), 16 were downregulated and 14 were upregulated. Prediction tools Diana-microT suggests a potential role of several nutriregulated miRNA in the lipid metabolism. Among putative targets 19 differently expressed genes (DEG) previously identified in the same sample, were found. Functions of these 19 DEG revealed their involvement in tissue remodeling. This study constitutes the first evidence of nutriregulated miRNA in the ruminant mammary gland. The characterization of these 30 miRNA could contribute to a better understanding of genes regulations in the mammary gland in response to nutrition. MicroRNA profiles of mammary glands from 10 Alpine goats at the peak of lactation (48 ± 2 days post-partum) generated by a HiSeq 2500 using Illumina Solexa technic.