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Walker C.G.,DairyNZ Ltd. | Walker C.G.,University of Auckland | Meier S.,DairyNZ Ltd. | Littlejohn M.D.,DairyNZ Ltd. | And 4 more authors.
BMC Genomics | Year: 2010

Background: A large proportion of pregnancy losses occur during the pre-implantation period, when the developing embryo is elongating rapidly and signalling its presence to the maternal system. The molecular mechanisms that prevent luteolysis and support embryo survival within the maternal environment are not well understood. To gain a more complete picture of these molecular events, genome-wide transcriptional profiles of reproductive day 17 endometrial tissue were determined in pregnant and cyclic Holstein-Friesian dairy cattle.Results: Microarray analyses revealed 1,839 and 1,189 differentially expressed transcripts between pregnant and cyclic animals (with ≥ 1.5 fold change in expression; P-value < 0.05, MTC Benjamini-Hochberg) in caruncular and intercaruncular endometrium respectively. Gene ontology and biological pathway analysis of differentially expressed genes revealed enrichment for genes involved in interferon signalling and modulation of the immune response in pregnant animals.Conclusion: The maternal immune system actively surveys the uterine environment during early pregnancy. The embryo modulates this response inducing the expression of endometrial molecules that suppress the immune response and promote maternal tolerance to the embryo. During this period of local immune suppression, genes of the innate immune response (in particular, antimicrobial genes) may function to protect the uterus against infection. © 2010 Walker et al; licensee BioMed Central Ltd.

Karim L.,University of Liege | Takeda H.,University of Liege | Lin L.,University of Liege | Druet T.,University of Liege | And 12 more authors.
Nature Genetics | Year: 2011

We report mapping of a quantitative trait locus (QTL) with a major effect on bovine stature to a ∼1/4780-kb interval using a Hidden Markov Model-based approach that simultaneously exploits linkage and linkage disequilibrium. We re-sequenced the interval in six sires with known QTL genotype and identified 13 clustered candidate quantitative trait nucleotides (QTNs) out of >9,572 discovered variants. We eliminated five candidate QTNs by studying the phenotypic effect of a recombinant haplotype identified in a breed diversity panel. We show that the QTL influences fetal expression of seven of the nine genes mapping to the ∼1/4780-kb interval. We further show that two of the eight candidate QTNs, mapping to the PLAG1-CHCHD7 intergenic region, influence bidirectional promoter strength and affect binding of nuclear factors. By performing expression QTL analyses, we identified a splice site variant in CHCHD7 and exploited this naturally occurring null allele to exclude CHCHD7 as single causative gene. © 2011 Nature America, Inc. All rights reserved.

Rawson P.,Victoria University of Wellington | Stockum C.,Victoria University of Wellington | Peng L.,Victoria University of Wellington | Manivannan B.,Victoria University of Wellington | And 9 more authors.
Journal of Proteomics | Year: 2012

The liver and the mammary gland have complementary metabolic roles during lactation. Glucose synthesized by the liver is released into the circulation and is taken up by the mammary gland where major metabolic products of glucose include milk sugar (lactose) and the glycerol backbone of milk fat (triglycerides). Hepatic synthesis of glucose is often accompanied by β-oxidation in that organ to provide energy for glucose synthesis, while mammary gland synthesizes rather than oxidizes fat during lactation. We have therefore compared enzyme abundances between the liver and mammary gland of lactating Friesian cows where metabolic output is well established. Quantitative differences in protein amount were assessed using two-dimensional differential in-gel electrophoresis. As predicted, the abundances of enzymes catalysing gluconeogenesis and β-oxidation were greatest in the liver, and enzyme abundances in mammary tissue were consistent with fat synthesis rather than β-oxidation. This article is part of a Special Issue entitled: Farm animal proteomics. © 2012 Elsevier B.V.

Kelly V.,University of Auckland | Davis S.,ViaLactia Biosciences | Berry S.,ViaLactia Biosciences | Melis J.,Livestock Improvement Corporation | And 6 more authors.
Journal of Dairy Science | Year: 2013

Non-protein-bound oligosaccharides are important bioactive components of cow milk, with potential human-health benefits such as stimulation of the growth of beneficial gut bacteria and defense against pathogens. In bovine milk, the majority of oligosaccharides are sialylated; 3'-sialyllactose (3'- N-acetylneuraminyl- d-lactose; 3'-SL) is the predominant sialylated oligosaccharide, followed by 6'-sialyllactose (6'- N-acetylneuraminyl- d-lactose; 6'-SL). Both 3'-SL and 6'-SL have antimicrobial activity. As bovine milk products such as infant formula can be an important component of the human diet, and the concentrations of 3'-SL and 6'-SL are lower in bovine milk compared with human milk, we aimed to identify cows that naturally produce higher concentrations of sialyllactose in their milk. Milk from such cows could be used to produce foods with an increased sialyllactose content, potentially providing increased health benefits. We speculated that cows overexpressing 3'-SL and 6'-SL would exist at low frequency in the population and, to allow their efficient identification, we developed a novel assay for 3'-SL and 6'-SL utilizing flow-injection analysis-mass spectrometry, which could be used for high-throughput analysis of milk samples. We then determined 3'-SL and 6'-SL concentrations in milk samples from 15,507 cows from Friesian, Jersey, and Friesian-Jersey crossbred animals. We found 329 cows with concentrations of 3'-SL or 6'-SL >2-fold higher than the mean, 26 cows with concentrations of 3'-SL or 6'-SL >3-fold higher than the mean, and 1 cow with concentrations of 3'-SL >4-fold higher than the mean. Although these outliers were observed across the 3 groups of cows, breed had a strong effect on mean 3'-SL and 6'-SL concentrations. © 2013 American Dairy Science Association.

Littlejohn M.D.,DairyNZ Ltd. | Walker C.G.,DairyNZ Ltd. | Ward H.E.,ViaLactia Biosciences | Lehnert K.B.,ViaLactia Biosciences | And 6 more authors.
Physiological Genomics | Year: 2010

Regulation of milk synthesis and secretion is controlled mostly through local (intramammary) mechanisms. To gain insight into the molecular pathways comprising this response, an analysis of mammary gene expression was conducted in 12 lactating cows shifted from twice daily to once daily milking. Tissues were sampled by biopsy from adjacent mammary quarters of these animals during the two milking frequencies, allowing changes in gene expression to be assessed within each animal. Using bovine-specific, oligonucleotide arrays representing 21,495 unique transcripts, a range of differentially expressed genes were found as a result of less frequent milk removal, constituting transcripts and pathways related to apoptotic signaling (NF-κB, JUN, ATF3, IGFBP5, TNFSF12A) mechanical stress and epithelial tight junction synthesis (CYR61, CTGF, THBS1, CLDN4, CLDN8), and downregulated milk synthesis (LALBA, B4GALT1, UGP2, CSN2, GPAM, LPL). Quantitative real-time PCR was used to assess the expression of 13 genes in the study, and all 13 of these were correlated (P < 0.05) with values derived from array analysis. It can be concluded that the physiological changes that occur in the bovine mammary gland as a result of reduced milk removal frequency likely comprise the earliest stages of the involution response and that mechano-signal transduction cascades associated with udder distension may play a role in triggering these events. © 2010 the American Physiological Society.

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