The lactose synthetase particles of lactating bovine mammary gland. Preparation of particles with intact lactose synthetase.
Ontology highlight
ABSTRACT:
SUBMITTER: Coffey RG
PROVIDER: S-EPMC1186771 | biostudies-other | 1968 Sep
REPOSITORIES: biostudies-other
Similar Datasets
Project description:1. The conditions that promoted the solubilization of particulate lactose synthetase were effective for solubilizing the thiamine pyrophosphatase of the Golgi apparatus but differed from those effective for beta-glucuronidase or acid phosphatase of lysosomes. 2. Lactose synthetase-containing particles did not bind Mg(2+) or Cs(+) ions, suggesting that they are not related to endoplasmic reticulum membranes. 3. Intact lactose synthetase and thiamine pyrophosphatase particles banded isopycnically at a density of 1.143 in a sucrose gradient. The dissociated ;A' sub-unit of lactose synthetase, UDP-galactose hydrolase, p-nitrophenyl phosphate acid phosphatase, alkaline phosphatase and phosphodiesterase I were associated with particles of a broad density range from 1.12 to 1.20. Lysosomal enzymes beta-glucuronidase, arylsulphatase and beta-glycerophosphate acid phosphatase were associated with particles of density 1.20, 1.175 and 1.15 respectively. 4. Rate-zonal sedimentation studies indicated that lactose synthetase particles have S(20,w) values exceeding 24000s, corresponding to spherical particles of diameter exceeding 5.4x10(-5)cm. 5. Electron micrographs of lactose synthetase particles purified over 20-fold revealed small spherical bodies (0.1-0.5mu) resembling lysosomes, the smaller of which were attached to membranes, and larger heterogeneous spherical or oval bodies (0.7-1.8mu) resembling lipofuscin secretory granules. 6. The relationship between lactose synthetase particles and the Golgi origin of secretion granules is discussed.
| S-EPMC1186772 | biostudies-other
Project description:BackgroundThe mammary gland is a dynamic organ that undergoes important physiological changes during reproductive cycles. Until now, data regarding the characterisation of miRNA in the mammary gland have been scarce and mainly focused on their abnormal expression in breast cancer. Our goal was to characterise the microRNA (miRNA) involved in mechanisms regulating the mammary function, with particular focus on the lactation stage.Methodology/principal findingsUsing high-throughput sequencing technology, the exhaustive repertoires of miRNA expressed (miRNome) in mouse and bovine mammary glands during established lactation were identified, characterized and compared. Furthermore, in order to obtain more information on miRNA loading in the RNA-induced silencing complex (RISC), the miRNome was compared with that obtained from RNA associated with the AGO2 protein (AGO2-miRNome) in mouse lactating mammary gland. This study enabled the identification of 164 and 167 miRNA in mouse and bovine, respectively. Among the 30 miRNA most highly expressed in each species, 24 were common to both species and six of them were preferentially highly expressed in lactating than non-lactating mammary gland. The potential functional roles of these 24 miRNA were deduced using DIANA-miRPath software, based on miRNA/mRNA interactions. Moreover, seven putative novel miRNA were identified. Using DAVID analysis, it was concluded that the predicted targets of two of these putative novel miRNA are involved in mammary gland morphogenesis.Conclusion/significanceOur study provides an overview of the characteristics of lactating mouse and bovine mammary gland miRNA expression profiles. Moreover, species-conserved miRNA involved in this fundamental biological function were identified. These miRNomes will now be used as references for further studies during which the impact of animal breeding on the miRNA expression will be analysed.
| S-EPMC3962357 | biostudies-literature
Project description:BackgroundLactose synthesis rate is an important factor in milk production and quality in mammals. Understanding the lactose synthesis mechanism is crucial for the improvement of milk quantity and quality. However, research on the temporal gene changes regarding lactose synthesis during the whole lactation is still limited. The objective of this study was to determine gene expression profiles related to lactose synthesis in sows during lactation, and further identify the critical steps or key factors in the lactose synthesis pathway.MethodsTo determine the temporal change of factors related to lactose synthesis in sows, milk from eight multiparous Yorkshire sows (parity 3 to 6) was collected at 0 h, 2 h, 6 h, 12 h, 24 h, day 2, 3, 4, 7, 14, and 21 after birth of the first piglet. Lactose content, prolactin and progesterone concentration, and gene or protein expression related to lactose synthesis were measured.ResultsThe lactose yield increased gradually from D2 to D21 and reached a maximum at D14 (3-fold from D2) during lactation (P < 0.05). A similar trend was observed in IGF-1 and insulin concentrations in milk, both of which were greatest at D3 with a subsequent decrease during middle to late lactation. Conversely, milk prolactin and progesterone concentrations moderately decreased with the progression of lactation. The mRNA or protein expressions related to glucose transportation (GLUT1), glucose-galactose interconversion (HK1 and UGP2), UDP-galactose transportation (SLC35A2), and lactose synthetase (LALBA and B4GALT1) in the lactose synthesis pathway were significantly upregulated during early to middle lactation and plateaued by late lactation (P < 0.05).ConclusionsThese novel findings suggest that the increased lactose synthesis in lactation was related to the coordinated upregulation of genes or enzymes in the lactose synthesis pathway, and glucose transportation (GLUT1) and lactose synthetase (LALBA and B4GALT1) might be the critical steps in the lactose synthesis pathway of sows during lactation.
| S-EPMC6001073 | biostudies-literature
Project description:The augmentation of lactose synthetase activity during late pregnancy and lactation was measured by using both a tissue-culture assay and a cell-free assay. The results indicated at least a 100-fold augmentation in specific activity between late pregnancy and lactation. The cell-free assay indicated that the activities of both subunits of this enzyme had increased to 20-30% of the value during lactation by the last day of pregnancy. The tissue-culture assay, however, showed activities only 3-4% of the maximum at the time of parturition. This suggests that not all the enzyme present in the tissue before lactation commenced was active. Since at all stages of pregnancy and lactation the B subunit, alpha-lactalbumin (which is also a milk protein), was rate-limiting, it is suggested that the rate of lactose synthesis may be linked to the rate of milk-protein synthesis. Both subunits of lactose synthetase could be induced in tissue culture by the hormones insulin+hydrocortisone+prolactin. Of the three hormones, prolactin appeared to be the ;trigger' that induced the synthesis of these proteins if the tissue had been stimulated previously by insulin+hydrocortisone.
| S-EPMC1184648 | biostudies-other
Project description:The Michaelis-Menten equation for the utilization of competing substrates was applied to the uptake of 2-deoxy[3H]glucose into the mammary gland of anaesthetized lactating rats. Intracellular water was calculated from total tissue water and sucrose space. Fed rats had a mean transport capacity of 2.2 mumol/min per g of tissue, giving an actual glucose transport in vivo of 1.1 mumol/min per g. Transport decreased by 90% on overnight starvation and returned to normal by 2 h of re-feeding. Similar changes were observed in the 1 min or 5 min transport of circulating 3-O-methylglucose. Transport of 3-O-methylglucose in starved rats was restored towards normal by insulin. In fed rats it increased between parturition and day 12 of lactation. The findings support the proposal that transport is a rate-limiting factor in the mammary utilization of carbohydrate.
| S-EPMC1153326 | biostudies-other
Project description:1. Ribosomes prepared from bovine lactating mammary gland are able to synthesize protein, whereas similar preparations from non-lactating glands are not. Washing the ribosome suspensions through a medium containing 0.5m-ammonium chloride enhanced their ability to incorporate phenylalanine into polyphenylalanine. 2. Ribosomes isolated from non-lactating bovine mammary gland, in contrast with those from rat liver and lactating mammary gland, contained significant amounts of extraneous nucleases. These enzymes could be removed by washing with a medium A buffer containing 0.5m-ammonium chloride. 3. Only those ribosomes from functionally active tissues were able to bind polyuridylic acid and phenylalanyl-tRNA.
| S-EPMC1176567 | biostudies-other
Project description:The objective of this study was to examine five different sources of RNA, namely mammary gland tissue (MGT), milk somatic cells (SC), laser microdissected mammary epithelial cells (LCMEC), milk fat globules (MFG) and antibody-captured milk mammary epithelial cells (mMEC) to analyze the bovine mammary gland transcriptome using RNA-Sequencing. Our results provide a comparison between different sampling methods (invasive and non-invasive) to define the transcriptome of mammary gland tissue and milk cells. This information will be of value to investigators in choosing the most appropriate sampling method for different research applications to study specific physiological states during lactation. One of the simplest procedures to study the transcriptome associated with milk appears to be the isolation of total RNA directly from SC or MFG released into milk during lactation. Our results indicate that the SC and MFG transcriptome are representative of MGT and LCMEC and can be used as effective and alternative samples to study mammary gland expression without the need to perform a tissue biopsy.
| S-EPMC5381611 | biostudies-literature
Project description:Background: The mammary gland is a dynamic organ that undergoes important physiological changes during reproductive cycles. Until now, data regarding the characterisation of miRNA in the mammary gland have been scarce and mainly focused on their abnormal expression in breast cancer. Our goal was to characterise the microRNA (miRNA) involved in mechanisms regulating the mammary function, with particular focus on the lactation stage Methodology/principal findings: Using high-throughput sequencing technology, an exhaustive repertoire of miRNA (miRNome) expressed in mouse and bovine mammary glands during established lactation was identified, characterised and compared. Furthermore, in order to obtain more information on miRNA loading in the RNA-induced silencing complex (RISC), the miRNome was compared with that obtained from RNA associated with the AGO2 protein (AGO2-miRNome) in mouse lactating mammary gland. This study enabled the identification of 164 and 167 miRNA in mouse and bovine, respectively. Among the 30 miRNA most highly expressed in each species, 24 were common to both species and six of them tended to be more highly expressed in lactating than in non-lactating mammary gland. The potential functional roles of these 24 miRNA were deduced using DIANA-miRPath software, based on miRNA/mRNA interactions. Moreover, seven putative novel miRNA were identified. Using DAVID analysis, it was concluded that the predicted targets of two of these putative novel miRNA are involved in mammary gland morphogenesis. Conclusion/significance: Our study provides an overview of the characteristics of lactating mouse and bovine mammary gland miRNA expression profiles. Moreover, species-conserved miRNA involved in this fundamental biological function were identified. These miRNomes will new be used as references for further studies during which the impact of animal breeding on the miRNA expression will be analysed.
2014-03-24 | GSE53511 | GEO
Project description:Citrullination is a post-translational modification (PTM) in which positively charged peptidyl-arginine is converted into neutral peptidyl-citrulline by peptidylarginine deiminase (PAD or PADI) enzymes. The full protein citrullinome in many tissues is unknown. Herein, we used mass spectrometry and identified 107 citrullinated proteins in the lactation day 9 (L9) mouse mammary gland including histone H2A, α-tubulin, and β-casein. Given the importance of prolactin to lactation, we next tested if it stimulates PAD-catalyzed citrullination using mouse mammary epithelial CID-9 cells. Stimulation of CID-9 cells with 5 µg/mL prolactin for 10 min induced a 2-fold increase in histone H2A citrullination and a 4.5-fold increase in α-tubulin citrullination. We next investigated if prolactin-induced citrullination regulates the expression of lactation genes β-casein (Csn2) and butyrophilin (Btn1a1). Prolactin treatment for 12 h increased β-casein and butyrophilin mRNA expression; however, this increase was significantly inhibited by the pan-PAD inhibitor, BB-Cl-amidine (BB-ClA). We also examined the effect of tubulin citrullination on the overall polymerization rate of microtubules. Our results show that citrullinated tubulin had a higher maximum overall polymerization rate. Our work suggests that protein citrullination is an important PTM that regulates gene expression and microtubule dynamics in mammary epithelial cells.
| S-EPMC7177251 | biostudies-literature
Project description:Background: The mammary gland is a dynamic organ that undergoes important physiological changes during reproductive cycles. Until now, data regarding the characterisation of miRNA in the mammary gland have been scarce and mainly focused on their abnormal expression in breast cancer. Our goal was to characterise the microRNA (miRNA) involved in mechanisms regulating the mammary function, with particular focus on the lactation stage Methodology/principal findings: Using high-throughput sequencing technology, an exhaustive repertoire of miRNA (miRNome) expressed in mouse and bovine mammary glands during established lactation was identified, characterised and compared. Furthermore, in order to obtain more information on miRNA loading in the RNA-induced silencing complex (RISC), the miRNome was compared with that obtained from RNA associated with the AGO2 protein (AGO2-miRNome) in mouse lactating mammary gland. This study enabled the identification of 164 and 167 miRNA in mouse and bovine, respectively. Among the 30 miRNA most highly expressed in each species, 24 were common to both species and six of them tended to be more highly expressed in lactating than in non-lactating mammary gland. The potential functional roles of these 24 miRNA were deduced using DIANA-miRPath software, based on miRNA/mRNA interactions. Moreover, seven putative novel miRNA were identified. Using DAVID analysis, it was concluded that the predicted targets of two of these putative novel miRNA are involved in mammary gland morphogenesis. Conclusion/significance: Our study provides an overview of the characteristics of lactating mouse and bovine mammary gland miRNA expression profiles. Moreover, species-conserved miRNA involved in this fundamental biological function were identified. These miRNomes will new be used as references for further studies during which the impact of animal breeding on the miRNA expression will be analysed. microRNA profiles of mammary glands from 2 FVB/N mice at lactation day-12 and mammary biopsies from 4 Holstein dairy cows at mid-lactation, generated by deep sequencing, using Illumina HiSeq 2000.
2014-03-24 | E-GEOD-53511 | biostudies-arrayexpress