Synergistic Actions of Glucocorticoid and Prolactin in Murine Milk-Protein Gene Expression

2018 ◽  
pp. 121-135 ◽  
Author(s):  
Mihir R. Banerjee ◽  
Ravi S. Menon
Keyword(s):  
Gene Expression ◽  
Milk Protein ◽  
Protein Gene ◽  
Milk Protein Gene ◽  
Milk Protein Gene Expression

Hormone-dependent milk protein gene expression in bovine mammary explants from biopsies at different stages of pregnancy

2004 ◽  
Vol 71 (2) ◽  
pp. 135-140 ◽  
Author(s):  
Paul A Sheehy ◽  
James J Della-Vedova ◽  
Kevin R Nicholas ◽  
Peter C Wynn
Keyword(s):  
Gene Expression ◽  
Milk Protein ◽  
Protein Gene ◽  
Bovine Milk ◽  
Mammary Tissue ◽  
Endocrine Regulation ◽  
Surgical Biopsy ◽  
Milk Protein Gene ◽  
Milk Protein Gene Expression

A method for the collection of mammary biopsies developed previously was refined and used to study the endocrine regulation of bovine milk protein gene expression. Our surgical biopsy method used real-time ultrasound imaging and epidural analgesia to enable recovery of a sufficient quantity of mammary tissue from late-pregnant dairy cows for explant culture in vitro. The time of biopsy was critical for prolactin-dependent induction of milk protein gene expression in mammary explants, as only mammary tissue from cows nearing 30 d prepartum was hormone-responsive. This suggests that during the later stages of pregnancy a change in the responsiveness of milk protein gene expression to endocrine stimuli occurred in preparation for lactation. This may relate to the diminution of a putative population of undifferentiated cells that were still responsive to prolactin. Alternatively, the metabolic activity of the tissue had increased to the level whereby the response of the tissue was no longer assessable using this model in vitro.

Effects of compensatory growth on milk protein gene expression and mammary differentiation

1988 ◽  
Vol 2 (10) ◽  
pp. 2619-2624 ◽  
Author(s):  
Chung S. Park ◽  
Yun J. Choi ◽  
Wanda L. Keller ◽  
Robert L. Harrold
Keyword(s):  
Gene Expression ◽  
Compensatory Growth ◽  
Milk Protein ◽  
Protein Gene ◽  
Milk Protein Gene ◽  
Milk Protein Gene Expression

scholarly journals  Gene expression of six major milk proteins in primary bovine mammary epithelial cells isolated from milk during the first twenty weeks of lactation

2012 ◽  
Vol 57 (No. 10) ◽  
pp. 469-480 ◽  
Author(s):  
T. Sigl ◽  
H.H.D. Meyer ◽  
S. Wiedemann
Keyword(s):  
Gene Expression ◽  
Epithelial Cells ◽  
Milk Protein ◽  
Protein Gene ◽  
Mammary Epithelial Cells ◽  
Mammary Epithelial ◽  
Milk Protein Gene ◽  
Bovine Mammary Epithelial Cells ◽  
Milk Protein Genes ◽  
Milk Protein Gene Expression

&nbsp;The objective of the present study was to refine a previously developed method to isolate primary bovine mammary epithelial cells (pBMEC) from fresh milk. Using this method, it was tested whether the number of pBMEC and the relation of recovered pBMEC to total somatic cell count vary within the individual lactation stages. Furthermore, the expression levels of the milk protein genes during the first twenty weeks of lactation were determined by quantitative PCR method. A total number of 152 morning milk samples were obtained from twenty-four Holstein-Friesian cows during the first 20 weeks of lactation (day 8, 15, 26, 43, 57, 113, and 141 postpartum). Numbers of extracted pBMEC were consistent at all time-points (1.1 &plusmn; 0.06 to 1.4 &plusmn; 0.03 &times;10<sup>3</sup>/ml) and an average value of RNA integrity number (RIN) was 6.3 &plusmn; 0.3. Percentage of pBMEC in relation to total milk cells (2.0 &plusmn; 0.2 to 6.7 &plusmn; 1.0%) correlated with milk yield. Expression patterns of the casein genes alpha (&alpha;)<sub>S1</sub>, (&alpha;)<sub>S2</sub>, beta (&beta;), and kappa (&kappa;) (CSN1S1, CSN1S2, CSN2, CSN3, respectively) and the whey protein genes &alpha;-lactalbumin (LALBA) and progestagen-associated endometrial protein (PAEP; known as &beta;-lactoglobulin) were shown to be comparable, i.e. transcripts of all six milk protein genes were found to peak during the first two weeks of lactation and to decline continuously towards mid lactation. However, mRNA levels were different among genes with CSN3 showing the highest and LALBA the lowest abundance. We hypothesized that milk protein gene expression has a pivotal effect on milk protein composition with no influence on milk protein concentration. This paper is the first to describe milk protein gene expression during lactation in pBMEC collected in milk. Future studies will be needed to understand molecular mechanisms in pBMEC including regulation of expression and translation throughout lactation. &nbsp;

scholarly journals Uncoupling the mechanisms that facilitate cell survival in hormone-deprived bovine mammary explants

2008 ◽  
Vol 41 (3) ◽  
pp. 103-116 ◽  
Author(s):  
Amelia J Brennan ◽  
Julie A Sharp ◽  
Christophe M Lefèvre ◽  
Kevin R Nicholas
Keyword(s):  
Gene Expression ◽  
Cell Survival ◽  
Milk Protein ◽  
Protein Gene ◽  
Mammary Epithelial Cells ◽  
Mammary Epithelial ◽  
Milk Protein Gene ◽  
Milk Protein Genes ◽  
Milk Protein Gene Expression ◽  
Lactogenic Hormones

Mammary explants can be hormonally stimulated to mimic the biochemical changes that occur during lactogenesis. Previous studies using mammary explants concluded that the addition of exogenous macromolecules were required for mammary epithelial cells to remain viable in culture. The present study examines the survival of mammary explants from the dairy cow using milk protein gene expression as a functional marker of lactation and cell viability. Mammary explants cultured from late pregnant cows mimicked lactogenesis and showed significantly elevated milk protein gene expression after 3 days of culture with lactogenic hormones. The subsequent removal of exogenous hormones from the media for 10 days resulted in the down-regulation of milk protein genes. During this time, the mammary explants remained hormone responsive, the alveolar architecture was maintained and the expression of milk protein genes was re-induced after a second challenge with lactogenic hormones. We report that a population of bovine mammary epithelial cells have an intrinsic capacity to remain viable and hormone responsive for extended periods in chemically defined media without any exogenous macromolecules. In addition, we found mammary explant viability was dependent on de novo protein and RNA synthesis. Global functional microarray analysis showed that differential expression of genes involved in energy production, immune responses, oxidative stress and apoptosis signalling might contribute to cell survival. As the decline in milk production in dairy cattle after peak lactation results in considerable economic loss, the identification of novel survival genes may be used as genetic markers for breeding programmes to improve lactational persistency in dairy cows.

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