The acute milk yield response to frequent milking in early lactation is mediated by genes transiently regulated by milk removal.
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ABSTRACT:
ORGANISM(S): Bos taurus
PROVIDER: GSE27380 | GEO | 2012/02/27
SECONDARY ACCESSION(S): PRJNA137019
REPOSITORIES: GEO
Similar Datasets
Project description:Milking dairy cows four times daily (4X) instead of twice daily (2X) during early lactation stimulates an increase in milk yield that partly persists through late lactation; however, the mechanisms behind this response are unknown. We hypothesized that the acute mammary response to regular milkings would be transient and would involve different genes from those that may be specifically regulated in response to 4X. Nine multiparous cows were assigned at parturition to unilateral frequent milking (UFM; 2X of the left udder half, 4X of the right udder half). Mammary biopsies were obtained from both rear quarters at 5 days in milk (DIM), immediately after 4X glands had been milked (Experiment 1; n = 4 cows), or 2.5 h after both udder halves had last been milked (Experiment 2; n = 5 cows). Affymetrix GeneChipM-BM-. Bovine Genome Arrays were used to measure gene expression. Eight hundred and fifty five genes were differentially expressed in mammary tissue between 2X vs. 4X glands of cows in experiment 1 (FDR M-bM-^IM-$ 0.05), whereas none were differentially expressed in experiment 2 using the same criterion. We conclude that there is an acute transcriptional response to milk removal, but 4X milking did not elicit differential expression of unique genes. Therefore, there does not appear to be a sustained transcriptional response to 4X milking on day 5 of lactation. Using a differential expression plot of data from both experiments, as well as qRT-PCR, we identified at least two genes that may be responsive to both milk removal and to 4X milking. Therefore, the milk yield response to 4X milking may be mediated by genes that are acutely regulated by removal of milk from the mammary gland. 8 samples from 4 cows in experiment 1; 6 samples from 3 cows in experiment 2
2012-02-27 | E-GEOD-27380 | biostudies-arrayexpress
Project description:Four-times daily milking during the first 3 weeks of lactation elicits an increase in milk yield, which persists through late lactation even after twice-daily milking is imposed. We hypothesized that this milk yield response would be associated with changes in mammary proliferation, apoptosis, and gene expression, which would persist throughout lactation. Six multiparous cows were assigned to unilateral frequent milking (UFM; twice daily milking of the left udder half (2X), four-times daily milking of the right udder half (4X)) on days 1 to 21 of lactation, followed by 2X thereafter. Udder halves initially milked 4X produced more milk than those milked 2X during, and after UFM treatment, through 180 days in milk (DIM). To determine the mechanisms involved in the persistent milk yield response, we obtained mammary biopsies from both udder halves at 21, 23, and 40 DIM. Rates of [3H]-thymidine incorporation into DNA in vitro and mammary cell apoptosis were not affected by UFM or DIM. Using Affymetrix GeneChipM-BM-. Bovine Genome Arrays, we determined that the differential expression (4X vs. 2X) of 18 genes was significantly affected by DIM. Within the group of 18 differentially expressed genes, we identified a cluster of 15 genes with a similar temporal pattern of differential expression. Nine of the genes in the cluster remained differentially expressed at 40 DIM, indicating that they may be involved in the persistent milk yield response. Among the genes in the cluster were chitinase 3-like (CHI3L)-1, clusterin, early growth response (EGR)-1, and sex determining region Y-box (SOX)-4. These genes have been associated with mammary development, differentiation and remodeling; all of which may be functionally related to the increase in milk yield. We conclude that frequent milking during early lactation does not alter mammary growth but is associated with changes in mammary expression of 18 genes. Future experiments will determine the function of these genes in the mammary gland, and will clarify their role in the autocrine regulation of milk production and long-term alteration of mammary function. 36 samples from 6 cows; 3 timepoints
2014-01-01 | E-GEOD-27851 | biostudies-arrayexpress
Project description:BACKGROUND: The lactating mammary gland responds to changes in milking frequency by modulating milk production. This response is locally regulated and, in dairy cows, the udder is particularly sensitive during early lactation. Relative to cows milked twice-daily throughout lactation, those milked four-times-daily for just the first 3 weeks of lactation produce more milk throughout that lactation. We hypothesized that the milk yield response would be associated with increased mammary cell turnover and changes in gene expression during frequent milking and persisting thereafter. Cows were assigned to unilateral frequent milking (UFM; left udder halves milked twice-daily; right udder halves milked four-times daily) on days 1 to 21 of lactation, followed by twice-daily milking for the remainder of lactation. Relative to udder halves milked twice-daily, those milked four-times produced more milk during UFM; the difference in milk yield declined acutely upon cessation of UFM after day 21, but remained significantly elevated thereafter. We obtained mammary biopsies from both udder halves on days 21, 23, and 40 of lactation. RESULTS: Mammary cell proliferation and apoptosis were not affected by milking frequency. We identified 75 genes that were differentially expressed between paired udder halves on day 21 but exhibited a reversal of differential expression on day 23. Among those genes, we identified four clusters characterized by similar temporal patterns of differential expression. Two clusters (11 genes) were positively correlated with changes in milk yield and were differentially expressed on day 21 of lactation only, indicating involvement in the initial milk yield response. Two other clusters (64 genes) were negatively correlated with changes in milk yield. Twenty-nine of the 75 genes were also differentially expressed on day 40 of lactation. CONCLUSIONS: Changes in milking frequency during early lactation did not alter mammary cell population dynamics, but were associated with coordinated changes in mammary expression of at least 75 genes. Twenty-nine of those genes were differentially expressed 19 days after cessation of treatment, implicating them in the persistent milk yield response. We conclude that we have identified a novel transcriptional signature that may mediate the adaptive response to changes in milking frequency.
2014-01-01 | GSE27851 | GEO
Project description:We hypothesized that accumulation of milk would influence gene expression in the mammary gland of lactating dairy cows. To test this hypothesis, we enrolled 4 multiparous Holstein cows (150 ± 10 DIM) in a half-udder milk stasis experiment. On day 1 of the experiment, cows were milked at 0430 h and at 1430 h, only right udder halves were milked. Mammary biopsies were obtained from both udder halves on day 2 of the experiment at 0500 h, immediately after right udder halves were milked and 12 h since left udder halves had last been milked. Using Affymetrix GeneChip® Bovine Genome Arrays, we identified 32 genes that were differentially expressed between left (full) and right (empty) udder halves (fold change > 1.5; P < 0.05). Four of the genes were downregulated in response to milk stasis, whereas 28 were upregulated. Differentially expressed genes were associated with extracellular matrix remodeling, tight junction formation, regulation of blood flow, and apoptosis. In addition, four of the differentially expressed genes had been previously identified as candidates for local regulation of milk production in dairy cows. Expression of two of these candidates, early growth response-1 (EGR-1) and thrombospondin-1 (THBS-1), was validated using real-time quantitative RT-PCR. Consistent with microarray results, both genes were upregulated in response to 24-h of milk stasis (P < 0.03). Immunofluorescence was used to localize expression of EGR-1 protein, which was restricted to epithelia and was uniformly distributed. We conclude that accumulation of milk alters gene expression in the bovine mammary gland. In particular, EGR-1 and THBS-1 have emerged as strong candidates for local regulation of milk production in dairy cows.
2014-01-01 | GSE27840 | GEO
Project description:Once daily milking reduces milk yield and alters mammary transcriptome resulting in a decrease in milk protein synthesis as well as an induction of the apoptotic signaling networks. A local regulation due to milk stasis in the tissue could contribute to this effect but such mechanisms have not yet been described. To challenge this hypothesis, cows were milked unilaterally, once daily on one udder half and twice daily on the other one, and variations in gene expression were studied in biopsies as well as in mammary epithelial cells (MEC) shed into milk during the lactation process (milk MEC). This study therefore also contributes to decipher if transcript variations in milk purified MEC can reflect that of the mammary tissue. We compared the mammary transcript profiles in biopsies collected from unilaterally once versus twice-daily milked udder halves, 504 transcripts were differentially expressed: 193 and 232 transcripts were up- and down-regulated, respectively. A first category of transcripts, which accumulation levels are mostly up-regulated, relates to mechanisms involved in cell renewal, such as cell cycle, cellular growth and proliferation, cell death and cellular development. A second family, mostly down-regulated, is involved in small molecule biochemistry, amino acid, lipid and carbohydrate metabolisms as well as molecular transport. A third category, mostly up-regulated, includes transcripts expressed in non-epithelial mammary cells such as adipocytes, endothelial and immune cells and cells from the connective tissue. These results are consistent with previous data showing a decrease in mammary synthesis activity and an activation of cell death during once daily milking. They further suggest that during once daily milking the local milk accumulation has a major effect on mammary remodeling. Interestingly, some transcripts belonged to a third family described as M-BM-+ molecular transports M-BM-;. The expression of the 21 mRNA was then analyzed by RT-par in MEC (Table 4). Seven transcripts (NUCB2, RNASE4, ABCG2, RNASE1, SLC34A2, Cap1, FABP3, LALBA, SCD) were significantly down-regulated in milk purified MEC. Six were also significantly down-regulated in mammary biopsies. These transcripts are mostly involved in milk synthesis. We therefore conclude that milk purified MEC cannot be used as general markers of variations occurring in the mammary tissue but that variations in some transcripts listed above can be useful indicators. In this experimental design, udder halves were unilaterally milked once daily and the contralateral udder halves twice daily. Each mammary biopsy RNA sample from one udder half was compared to the one of the contralateral udder half in 5 dye-swaps corresponding to 5 animal replications, minimizing the animal variability. One dye swap corresponded to one comparison meaning two slides.
2013-08-27 | E-GEOD-43505 | biostudies-arrayexpress
Project description:We hypothesized that accumulation of milk would influence gene expression in the mammary gland of lactating dairy cows. To test this hypothesis, we enrolled 4 multiparous Holstein cows (150 M-BM-1 10 DIM) in a half-udder milk stasis experiment. On day 1 of the experiment, cows were milked at 0430 h and at 1430 h, only right udder halves were milked. Mammary biopsies were obtained from both udder halves on day 2 of the experiment at 0500 h, immediately after right udder halves were milked and 12 h since left udder halves had last been milked. Using Affymetrix GeneChipM-BM-. Bovine Genome Arrays, we identified 32 genes that were differentially expressed between left (full) and right (empty) udder halves (fold change > 1.5; P < 0.05). Four of the genes were downregulated in response to milk stasis, whereas 28 were upregulated. Differentially expressed genes were associated with extracellular matrix remodeling, tight junction formation, regulation of blood flow, and apoptosis. In addition, four of the differentially expressed genes had been previously identified as candidates for local regulation of milk production in dairy cows. Expression of two of these candidates, early growth response-1 (EGR-1) and thrombospondin-1 (THBS-1), was validated using real-time quantitative RT-PCR. Consistent with microarray results, both genes were upregulated in response to 24-h of milk stasis (P < 0.03). Immunofluorescence was used to localize expression of EGR-1 protein, which was restricted to epithelia and was uniformly distributed. We conclude that accumulation of milk alters gene expression in the bovine mammary gland. In particular, EGR-1 and THBS-1 have emerged as strong candidates for local regulation of milk production in dairy cows. 8 samples from 4 cows
2014-01-01 | E-GEOD-27840 | biostudies-arrayexpress
Project description:The ruminant liver has multiple roles in the dairy cow and many of these are crucial in nutrient supply during lactation. Reduced feed intake alters the expression of many genes and pathways in the liver, inducing a period of negative energy balance. Once-daily milking is a management strategy to reduce the effects of periods of negative energy balance so the objective of this study was to determine if once-daily milking altered hepatic gene transcription during a period of negative energy balance induce by caloric restriction. Multiparous Holstein-Friesian and Holstein-Friesian x Jersey cows (n = 120) were grazed on pasture and milked twice daily (2X) from calving until 34 ± 6 days in milk (mean ± standard deviation). Cows were then allocated to one of four treatments in a 2 x 2 factorial arrangement. Treatments consisted of two milking frequencies (2X or once daily; 1X) and two feeding levels for three weeks: adequately fed (AF), consuming 14.3 kg dry matter intake/cow per d, or underfed (UF) consuming 8.3 kg dry matter intake /cow per d. After the treatment period, all cows were fed to target grazing residuals ? 1600 kg DM/cow per d and milked 2X for 20 wk. Liver tissue was collected from 12 cows per treatment by subcutaneous biopsy at 3 wk relative to treatment start, RNA extracted and transcript abundance of genes quantified.
2014-01-08 | GSE47925 | GEO
Project description:Transcript profiling was performed by Affymetrix microarray analysis and SAGE to characterize changes in gene expression in the bovine mammary gland in response to 4× versus 2× daily milking during the first week of lactation. These changes in gene expression may contribute to the increased milk production observed in response to increased milking frequency. Our results indicate that increased milking frequency alters expression of genes in the mammary gland related to increased extracellular matrix remodeling, neovascularization, metabolism, cell proliferation and apoptosis. Keywords: Physiological response to stimulus Multiparous Holstein cows were milked either 2× daily (Control, n = 3) or 2× daily from day 1 to 3 of lactation, and 4× daily beginning at day 4 of lactation until day 21 post partum (IMF4, n = 4). The milking intervals were approximately 12 hours for Control cows and 9, 3, 9, and 3 hours, respectively, for IMF4 cows. Mammary biopsies were obtained at approximately day 7 of lactation for extraction of total RNA and subsequent transcript profiling my microarray (Affymetrix). Pooled Control and IMF4 RNA samples were used to synthesize two SAGE libraries using the Long SAGE kit by Invitrogen.
2007-12-22 | E-GEOD-9344 | biostudies-arrayexpress
Project description:Once daily milking reduces milk yield and alters mammary transcriptome resulting in a decrease in milk protein synthesis as well as an induction of the apoptotic signaling networks. A local regulation due to milk stasis in the tissue could contribute to this effect but such mechanisms have not yet been described. To challenge this hypothesis, cows were milked unilaterally, once daily on one udder half and twice daily on the other one, and variations in gene expression were studied in biopsies as well as in mammary epithelial cells (MEC) shed into milk during the lactation process (milk MEC). This study therefore also contributes to decipher if transcript variations in milk purified MEC can reflect that of the mammary tissue. We compared the mammary transcript profiles in biopsies collected from unilaterally once versus twice-daily milked udder halves, 504 transcripts were differentially expressed: 193 and 232 transcripts were up- and down-regulated, respectively. A first category of transcripts, which accumulation levels are mostly up-regulated, relates to mechanisms involved in cell renewal, such as cell cycle, cellular growth and proliferation, cell death and cellular development. A second family, mostly down-regulated, is involved in small molecule biochemistry, amino acid, lipid and carbohydrate metabolisms as well as molecular transport. A third category, mostly up-regulated, includes transcripts expressed in non-epithelial mammary cells such as adipocytes, endothelial and immune cells and cells from the connective tissue. These results are consistent with previous data showing a decrease in mammary synthesis activity and an activation of cell death during once daily milking. They further suggest that during once daily milking the local milk accumulation has a major effect on mammary remodeling. Interestingly, some transcripts belonged to a third family described as « molecular transports ». The expression of the 21 mRNA was then analyzed by RT-par in MEC (Table 4). Seven transcripts (NUCB2, RNASE4, ABCG2, RNASE1, SLC34A2, Cap1, FABP3, LALBA, SCD) were significantly down-regulated in milk purified MEC. Six were also significantly down-regulated in mammary biopsies. These transcripts are mostly involved in milk synthesis. We therefore conclude that milk purified MEC cannot be used as general markers of variations occurring in the mammary tissue but that variations in some transcripts listed above can be useful indicators.
2013-08-27 | GSE43505 | GEO
Project description:The ruminant liver has multiple roles in the dairy cow and many of these are crucial in nutrient supply during lactation. Reduced feed intake alters the expression of many genes and pathways in the liver, inducing a period of negative energy balance. Once-daily milking is a management strategy to reduce the effects of periods of negative energy balance so the objective of this study was to determine if once-daily milking altered hepatic gene transcription during a period of negative energy balance induce by caloric restriction. Multiparous Holstein-Friesian and Holstein-Friesian x Jersey cows (n = 120) were grazed on pasture and milked twice daily (2X) from calving until 34 ± 6 days in milk (mean ± standard deviation). Cows were then allocated to one of four treatments in a 2 x 2 factorial arrangement. Treatments consisted of two milking frequencies (2X or once daily; 1X) and two feeding levels for three weeks: adequately fed (AF), consuming 14.3 kg dry matter intake/cow per d, or underfed (UF) consuming 8.3 kg dry matter intake /cow per d. After the treatment period, all cows were fed to target grazing residuals ? 1600 kg DM/cow per d and milked 2X for 20 wk. Liver tissue was collected from 12 cows per treatment by subcutaneous biopsy at 3 wk relative to treatment start, RNA extracted and transcript abundance of genes quantified. 48 animals were enrolled in this study, a liver sample from 45 animals was used for microarray analysis. A reference design was used for hybridisation, whereby each of the 46 samples were hybridised to individual microarrays along with a pooled reference sample. The reference sample was generated by taking equal concentrations of each of the experimental samples.
2014-01-08 | E-GEOD-47925 | biostudies-arrayexpress