ABSTRACT: Microarray-based gene expression profiling of peripheral blood mononuclear cells in dairy cows with experimental hypocalcaemia and milk fever
Project description:Peripheral blood mononuclear cells (PBMC) from cows with experimentally induced hypocalcaemia or spontaneous milk fever were subject of an oligo-microarray analysis following quantitative real-time reverse transcription PCR (q-PCR). In experimental hypocalcaemia induced by 10 % Na2EDTA infusion (n = 4), the microarray revealed that 32 genes were significantly up- or down-regulated compared to control treatment by 11 % CaEDTA infusion (n = 4). In milk fever cases (n = 8), the microarray demonstrated that 98 genes were expressed differentially higher or lower compared to healthy parturient cows (n = 5). From both data, five genes were selected to be strongly related to both experimental hypocalcaemia and milk fever. Additionally, another gene was judged to be specific for milk fever independent of hypocalcaemia. The mRNA expressions of these six genes in milk fever cases were verified by q-PCR, which were significantly higher or lower than those in healthy parturient cows.
Project description:The liver of dairy cows naturally displays a series of metabolic adaptation during the periparturient period in response to the increasing nutrient requirement of lactation. The hepatic adaptation is partly regulated by insulin resistance and it is affected by the prepartal energy intake level of cows. We aimed to investigate the metabolic changes in the liver of dairy cows during the periparturient at gene expression level and to study the effect of prepartal energy level on the metabolic adaptation at gene expression level.B13:N13
Project description:Peripheral blood mononuclear cells (PBMC) from cows with experimentally induced hypocalcaemia or spontaneous milk fever were subject of an oligo-microarray analysis following quantitative real-time reverse transcription PCR (q-PCR). In experimental hypocalcaemia induced by 10 % Na2EDTA infusion (n = 4), the microarray revealed that 32 genes were significantly up- or down-regulated compared to control treatment by 11 % CaEDTA infusion (n = 4). In milk fever cases (n = 8), the microarray demonstrated that 98 genes were expressed differentially higher or lower compared to healthy parturient cows (n = 5). From both data, five genes were selected to be strongly related to both experimental hypocalcaemia and milk fever. Additionally, another gene was judged to be specific for milk fever independent of hypocalcaemia. The mRNA expressions of these six genes in milk fever cases were verified by q-PCR, which were significantly higher or lower than those in healthy parturient cows. In the experimental hypocalcemia study, four healthy nonpregnant, non-lactating ovariectomised Holstein cows were used. The experiment was performed according to a 2 M-CM-^W 2 crossover design with 2 weeks intervals. Cows were infused with either Na2EDTA (hypocalcaemic treatment) or CaEDTA (control treatment) solution during a period of 4 h. The animals were monitored for clinical signs of hypocalcaemia (dry nose, staggering, astasia, reduced ruminal activity, increased heart rate, increased respiratory frequency, sweating, and ear cold). Infusion of EDTA solution was temporarily suspended when hypocalcaemia induced astasia was represent. If affected cow stood again, EDTA infusion was resumed. PBMC samples were collected before the start of infusion (0 h; pre-treatment) and at 4 and 24 h after the start of infusion 24h and utilized for gene expression analysis of PBMC. In the spontaneous milk fever study, a total of 13 Holstein dairy cows, which were 8 parturient cows diagnosed with milk fever within 2 days postpartum and 5 clinically healthy parturient cows within 2 days after parturition (Group H), were used. All spontaneous milk fever cases showed hypocalcaemia (< 1.8 mmol/l) in the blood samples obtained before the first treatment, and were treated by an intravenous infusion of a 20 % Ca borogluconate solution (500 ml). The milk fever cases were divided into two categories according to the reponse of the cows to the first Ca treatment: an immediate response in which the cow could stand within 1 day after a single Ca treatment (Group A, n = 4) and a requirement further treatment over 1 day after a single Ca treatment (Group B, n = 4). PBMC samples were collected vein just before the first Ca treatment in groups A and B and within 2 days postpartum in group H and utilized for gene expression analysis of PBMC.
Project description:Nitrogen (N) emissions became a huge topic under environmental and nutrient concerns in dairy farming. Nitrogen is metabolized in cows as a consequence of feed crude protein digestion which is either recycled or excreted via urine, faeces and/or milk. In dairy cows differences between cows in N-recycling and N-emissions have been postulated. This study investigated 24 Holstein dairy cows in late lactation. The experimental design comprises two dietary groups (low (LP) vs normal (NP) crude protein) and two groups of milk urea content, high (HMU) vs low (LMU). Transcriptomic profiles of the liver, rumen, mammalian gland and kidney tissues were comparatively assessed by mRNA sequencing.
Project description:Heat stress (HS) has become a major challenge in the dairy industry around the world. Although numerous measures have been taken to alleviate the HS impact on milk production, the cellular level response to HS remains unclear in dairy cows. The objective of this study was to dissect functional alterations based on transcriptomic dynamics in the liver of cows under HS. Dairy cows exposed to HS exhibited both decreased feed intake and milk yield. Through liver transcriptomic analysis, differentially expressed genes were identified among three experimental conditions, including heat stress (HS), pair-fed (PF), and thermoneutral (TN) groups. We observed the upregulation of protein folding and inflammation-related genes in the HS group, while the mitochondrial genes were downregulated. Gene functional enrichment also revealed that mitochondria function and oxidative phosphorylation were dysregulated under HS. The liver transcriptome analysis generated a comprehensive gene expression regulation network upon HS in lactating dairy cows. Overall, this study provides novel insights into molecular and metabolic changes of cows conditioned under HS. Our results could facilitate the development of efficient biomarkers to mitigate the negative effect of HS on dairy cow health and productivity.
Project description:Liver plays a profound role in the acute phase response (APR) observed in the early phase of acute bovine mastitis caused by Escherichia coli (E. coli). To gain an insight into the genes and pathways involved in hepatic APR of dairy cows we performed a global gene expression analysis of liver tissue sampled at different time points before and after intra-mammary (IM) exposure to E. coli lipopolysaccharide (LPS) treatment. Experiment Overall Design: Eight healthy, high yielding Holstein-Friesian dairy cows in their first lactation (9 to 12 weeks after calving) were chosen for this study. At time 0 the right front quarter was infused with 200 μg E. coli LPS dissolved in 10 ml 0.9% NaCl solution, the left front quarter serving as control was infused with 10 ml 0.9% NaCl solution. Liver biopsies were taken at â22, 3, 6, 9, 12 and 48 hours relative to LPS infusion in 4 cows, and also at â22, 9 and 48 hours in the remaining 4 cows. RNA from liver biopsies was isolated and biotin labeled cRNA was loaded onto the Affymetric GeneChip Bovine Genome Array. A control study using cows infused with 0.9% NaCl showed that there was no effect of taking the biopsy, neither in the clinical measurement nor in the expression of a selected subset of genes. Therefore, only samples taken from the LPS treated cows were measured for the gene expression using microarrays.
Project description:The severity of negative energy balance (NEB) in high-producing dairy cows has a high incidence among health diseases. The periparturient period is crucial for the health status and reproductive performance of dairy cows. During this period, dairy cows experience a transition from a pregnant, non-lactating state to a non-pregnant, lactating state. At the beginning of lactation, the energy needs for milk production are higher than the available energy consumed from feed intake, resulting in a negative energy balance (NEB)]. While in a NEB, cows mobilise their reserves from adipose tissue, resulting in elevated plasma concentrations of non-esterified fatty acids (NEFAs), which are used as a fuel source by peripheral tissues and the mammary gland for milk fat synthesis. Thus, white adipose tissue is one of the main tissue involved in the energy production during this transition period. So the objectives of our study were to dentify mRNA differentially expressed in white adipose before and after calving in dairy cow fed with low (LE) and high (HE) energy diet.
Project description:The objective of this study was to determine the effect of the DGAT1 K232A polymorphism on the global mRNA expression pattern of genes in the mammary gland tissue of grazing dairy cows in order to get more insight into the effects of this polymorphism on the physiology of the mammary glandgland of grazing dairy cows. Microarray analysis was used to identify genes whose expression was affected by the DGAT1 polymorphism in the mammary gland biopsies of 9 A232A cows, 13 K232A cows, and 4 K232K cows. The Microarray Analysis of Variance (MAANOVA) and Factor Analysis for Multiple Testing method (FAMT) were used to associate the expression of the genes present on Affymettrix Bovine Genome Arrays with the DGAT1 polymorphism. The data was also analysed at the level of functional modules by gene set enrichment analysis. In this experimental setting, DGAT1 polymorphism did not modify milk yield and composition significantly, although changes occurred in the yields of C14:0, C16:1cis-9, and some long chain fatty acids in milk. The DGAT1 polymorphism resulted in 30 differentially expressed genes related to cell growth, proliferation and development, signalling, remodelling and immune system. At the functional level, the pathways most affected by DGAT1 polymorphism were related to lipid biosynthesis, which likely reflected counter mechanisms of mammary tissue to respond to changes in milk FA composition, signalling, as well as immune system responses.