Gene expression of leptin, leptin receptor, prolactin receptor and whey acidic protein in mammary glands of late-pregnant gilts from two breeds

2004 ◽  
Vol 84 (4) ◽  
pp. 621-629 ◽  
Author(s):  
M. F. Palin ◽  
D. Beaudry ◽  
C. Farmer
Keyword(s):  
Gene Expression ◽  
Mammary Gland ◽  
Leptin Receptor ◽  
Prolactin Receptor ◽  
Mammary Glands ◽  
Whey Acidic Protein ◽  
Acidic Protein ◽  
Mrna Levels ◽  
Parenchymal Tissue ◽  
Receptor Mrna

In order to identify genes which are essential for pig mammary gland development, mRNA levels of prolactin receptor (PRL-R), leptin, leptin receptor and whey acidic protein (WAP) were measured in parenchymal tissue of 110-d-pregnant gilts. Thirteen Upton-Meishan (UM) and 14 Large White (LW) pregnant gilts and 5 non-pregnant control gilts (2 LW and 3UM) were used. PRL-R and WAP mRNA levels were higher in pregnant than in non-pregnant gilts (P < 0.05). Leptin mRNA levels were higher in UM than in LW gilts (P < 0.05), but this breed effect was not seen when leptin mRNA levels were corrected for percent fat in parenchyma. Correlations were found between concentrations of IGF-I in plasma and PRL-R (P < 0.01) and WAP (P < 0.05) mRNA levels in UM gilts. Serum prolactin (PRL) was correlated with leptin mRNA levels in the overall (P < 0.05) and LW (P < 0.05) populations of gilts, while estradiol was associated with leptin receptor mRNA in UM gilts (P < 0.05). The mRNA levels of all studied genes were positively correlated with mammary parenchymal and extra parenchymal weights in UM gilts, whereas these variables were only correlated with PRL-R and WAP gene expression in LW gilts. The presence of leptin and leptin receptor mRNA in parenchymal tissue suggests a paracrine role for leptin in mammary tissue of late-pregnant gilts. These results also suggest that the PRL signalling pathway is fully active at the transcriptional level in the mammary gland of gilts at 110 d of pregnancy. Key words: Genetics, pig, mammary glands, Meishan, mRNA

scholarly journals Molecular characterisation and hormone-dependent expression of the porcine whey acidic protein gene

1998 ◽  
Vol 20 (1) ◽  
pp. 27-35 ◽  
Author(s):  
KJ Simpson ◽  
P Bird ◽  
D Shaw ◽  
K Nicholas
Keyword(s):  
Gene Expression ◽  
Mammary Gland ◽  
Amino Acid ◽  
Amino Acid Sequence ◽  
Amino Acid Level ◽  
Whey Acidic Protein ◽  
Acidic Protein ◽  
Northern Analysis ◽  
Major Protein ◽  
Sds Page

A 17.5 kDa protein was isolated from porcine whey by reverse phase HPLC and identified as a putative whey acidic protein (WAP) homologue by sequencing 35 and 40 amino acid residues of the amino- and carboxy-terminus respectively. Degenerate oligonucleotides to both of these amino acid sequences were designed and used in reverse transcriptase PCR with RNA from lactating porcine mammary gland as a template. A 162 bp PCR fragment was detected and sequenced. Compilation of the deduced and determined amino acid sequence revealed a protein of 111 amino acids, which had approximately 75, 50, 40 and 35% similarity at amino acid level to camel, rabbit, rat and mouse WAP respectively. It also included the four-disulphide core characteristic of all WAP proteins and most Kunitz-type protease inhibitors. This provides the first unequivocal evidence for WAP secretion in the pig. SDS PAGE analysis of the whey fraction showed that WAP is secreted as a major protein in sow's milk from farrowing to weaning. The molecular mass of WAP in SDS PAGE was significantly greater than the 11.7 kDa determined from amino acid sequence, indicating that porcine WAP is possibly glycosylated. Northern analysis detected a single mRNA transcript of approximately 600 bp in porcine RNA from the mammary gland of lactating sows. To examine the hormone-regulated expression of the WAP gene the mammary glands of sows at day 90 of pregnancy were biopsied and explants cultured for 3 days in the presence of various combinations of porcine insulin (I), cortisol (F) and porcine prolactin (P). Northern analysis of RNA extracted from the tissue indicated that WAP gene expression was barely detectable in the mammary gland prior to culture and there was no increment in explants cultured in the presence of I and F. However, a significant increase in the accumulation of WAP mRNA was observed in explants cultured in I, F and P. A similar result was observed for beta-casein and alpha-lactalbumin gene expression.

scholarly journals Secretory proteins compete for production in the mammary gland of transgenic mice

1995 ◽  
Vol 310 (2) ◽  
pp. 637-641 ◽  
Author(s):  
M McClenaghan ◽  
A Springbett ◽  
R M Wallace ◽  
C J Wilde ◽  
A J Clark
Keyword(s):  
Mammary Gland ◽  
Transgenic Mice ◽  
Milk Protein ◽  
Milk Proteins ◽  
Whey Acidic Protein ◽  
Acidic Protein ◽  
Host Protein ◽  
Secretory Proteins ◽  
Mrna Levels ◽  
Endogenous Proteins

To explore the possibility that genes might compete for expression, we have studied transgenic mice producing high levels of the sheep milk protein, beta-lactoglobulin (BLG), in the mammary gland. Mice carrying one or more transgene loci expressed BLG in milk at levels ranging from 7 to 33 mg/ml. The effects of BLG synthesis on the levels of endogenous milk gene expression were examined. No significant increase in total milk protein concentration was recorded even in mice expressing the largest amounts of BLG. Measurement of individual milk proteins showed that transgene protein was manufactured at the expense of host protein synthesized in the gland. Whey acidic protein production was more suppressed than casein production. Suppression of endogenous proteins was matched by a reduction in the corresponding steady-state mRNA levels; in double-transgenic mice, which expressed the largest amounts of BLG, beta-casein and whey acidic protein mRNA populations were reduced to 75 and 56% of control levels respectively. We demonstrate that an exogenous gene competes effectively for expression with endogenous genes. Possible mechanisms of competition are discussed.

Progesterone and EGF inhibit mouse mammary gland prolactin receptor and beta-casein gene expression

1994 ◽  
Vol 267 (5) ◽  
pp. C1467-C1472 ◽  
Author(s):  
S. Nishikawa ◽  
R. C. Moore ◽  
N. Nonomura ◽  
T. Oka
Keyword(s):  
Gene Expression ◽  
Mammary Gland ◽  
Prolactin Receptor ◽  
Mammary Epithelium ◽  
Mouse Mammary Gland ◽  
Mrna Levels ◽  
Casein Gene ◽  
Beta Casein

Regulation of mouse mammary gland long-form prolactin receptor (PRL-RL) mRNA levels by progesterone and epidermal growth factor (EGF) and the relationship between PRL-RL and beta-casein gene expression were examined in vivo and in vitro. PRL-RL and beta-casein mRNA levels increased approximately 6- and 15-fold from the pregnant to the lactating period, respectively, when normalized to the level of beta-actin mRNA. Ovariectomy of pregnant mice rapidly reduced the serum concentration of progesterone and increased the level of PRL-RL and beta-casein mRNAs approximately three- and fourfold compared with sham-operated animals 24 h after the operation. Injection of progesterone, but not estrogen, inhibited the increase in both mRNA levels. PRL-RL and beta-casein mRNA levels in cultured mammary epithelium increased in response to insulin, hydrocortisone, and prolactin, whereas progesterone or EGF caused inhibition. The combination of EGF and progesterone produced a greater inhibition than either hormone alone. These results indicate that both progesterone and EGF serve as negative regulators of lactogenesis.

scholarly journals Effects of Weaning and Suckling on γ-Casein and Prolactin Receptor mRNA Levels in the Mouse Mammary Gland during Lactation

1998 ◽  
Vol 69 (8) ◽  
pp. 728-733
Author(s):  
Jae-Young KIM ◽  
Yasushi MIZOGUCHI ◽  
Takeshi KURAISHI ◽  
Hirohito YAMAGUCHI ◽  
Jumpei ENAMI ◽  
...  
Keyword(s):  
Mammary Gland ◽  
Prolactin Receptor ◽  
Mouse Mammary Gland ◽  
Mrna Levels ◽  
Receptor Mrna

Transferrin gene expression in the mammary gland of the rat. The enhancing effect of 17β-oestradiol on the level of RNA is tissue-specific

1993 ◽  
Vol 11 (2) ◽  
pp. 151-159 ◽  
Author(s):  
R Escalante ◽  
L-M Houdebine ◽  
M Pamblanco
Keyword(s):  
Gene Expression ◽  
Mammary Gland ◽  
Fold Increase ◽  
Mammary Glands ◽  
Mammary Tissue ◽  
Specific Response ◽  
Mrna Levels ◽  
Dot Blot ◽  
Pregnant Rats ◽  
Transferrin Gene

ABSTRACT We have investigated the physiological factors which regulate transferrin gene expression in the mammary gland of the rat. Our studies by dot blot analysis have demonstrated that multiple doses of 17β-oestradiol (OE2; 0·5 mg/kg per day for 3 days) elicit a specific 3·5-fold increase in the transferrin mRNA levels in the mammary glands of virgin rats. The hormonal action of OE2 in mammary tissue was specific for the transferrin gene, as judged by hybridization with β-actin cDNA. The accmulation of transferrin mRNA induced by OE2 treatment was similar to the developmentally regulated expression of the gene observed during the reproductive cycle. The steady-state level of mammary transferrin mRNA increased by up to 4·5-fold at day 21 of lactation, when compared with virgin and pregnant rats. Our results show that the pattern of transferrin gene expression is different in mouse and rat mammary glands. The specific response of the transferrin gene to OE2 was not found in the liver or in the uterus. In the uterus alone, OE2 produced a significant increase in the content of nucleic acids and also induced the accumulation of transferrin and β-actin mRNAs. We have detected for the first time an induction of transferrin gene expression in the mammary gland in response to OE2, and these results support the view that the pattern of transferrin gene multimodulated expression is tissue- and species-specific.

Expression levels of STAT5A and STAT5B in mammary parenchymal tissue from Upton-Meishan and Large White gilts

2002 ◽  
Vol 82 (4) ◽  
pp. 507-518 ◽  
Author(s):  
M. F. Palin ◽  
D. Beaudry ◽  
C. Roberge ◽  
C. Farmer
Keyword(s):  
Mammary Gland ◽  
Mammary Gland Development ◽  
Target Genes ◽  
Mammary Glands ◽  
Mammary Tissue ◽  
Mrna Levels ◽  
Large White ◽  
Parenchymal Tissue ◽  
Tissue Weight ◽  
Gland Development

The implication of STAT5A and STAT5B in mammary gland development and maintenance of lactation is well documented in rodents and humans. However, little is known regarding their roles in mammary gland development during gestation in pigs. We identified and analyzed the complete coding sequences of swine STAT5A and STAT5B and evaluated their mRNA levels in mammary glands of gestating gilts (day 110) in two different breeds, Upton-Meishan and Large White. Sequence analysis revealed a new APASA insertion in the STAT5A amino acid sequence that is in close proximity to residue Tyr 699 and whose phosporylation leads to the activation of target genes’ transcription. STAT5A mRNA levels were higher in Upton-Meishan than in Large White. In both breeds, STAT5B mRNA levels were higher than those of STAT5A , which is contrary to what was found in other mammals. A correlation between circulating IGF-I levels and STAT5B mRNA levels in the mammary gland was noticed in the Upton-Meishan breed only. STAT5B mRNA levels in mammary tissue of Large White gilts were highly correlated with extra-parenchymal tissue weight, parenchymal tissue weight, total parenchymal DNA, RNA and RNA/DNA ratio. In Upton-Meishan gilts, correlations were observed only between extra-parenchymal weight and STAT5A and STAT5B mRNA levels. These results indicate that there are significant differences in mRNA levels of STAT5A and STAT5B in the mammary glands of pregnant gilts when compared to other mammals, and between swine breeds. Key words: Mammary glands, signal transducers, pregnancy, kinases, pig, expression

scholarly journals Characterization and Regulation of Type A Endothelin Receptor Gene Expression in Bovine Luteal Cell Types

Endocrinology ◽  
1999 ◽  
Vol 140 (5) ◽  
pp. 2110-2116 ◽  
Author(s):  
Roni Mamluk ◽  
Nitzan Levy ◽  
Bo Rueda ◽  
John S. Davis ◽  
Rina Meidan
Keyword(s):  
Gene Expression ◽  
Receptor Gene ◽  
Cell Types ◽  
Cell Populations ◽  
Mrna Levels ◽  
Factor I ◽  
Receptor Mrna ◽  
Progesterone Production ◽  
Eta Receptor ◽  
Receptor Gene Expression

Abstract Our previous studies demonstrated that endothelin-1 (ET-1), a 21-amino acid vasoconstrictor peptide, has a paracrine regulatory role in bovine corpus luteum (CL). The peptide is produced within the gland where it inhibits progesterone production by acting via the selective type A endothelin (ETA) receptors. The present study was designed to characterize ETA receptor gene expression in different ovarian cell types and its hormonal regulation. ETA receptor messenger RNA (mRNA) levels were high in follicular cells as well as in CL during luteal regression. At this latter stage, high ETA receptor expression concurred with low prostaglandin F2α receptor mRNA. The ETA receptor gene was expressed by all three major cell populations of the bovine CL; i.e. small and large luteal cells, as well as in luteal endothelial cells. Among these various cell populations, the highest ETA receptor mRNA levels were found in endothelial cells. cAMP elevating agents, forskolin and LH, suppressed ETA receptor mRNA expression in luteinized theca cells (LTC). This inhibition was dose dependent and was evident already after 24 h of incubation. In luteinized granulosa cells (LGC), 10 and 100 ng/ml of insulin-like growth factor I and insulin (only at a concentration of 2000 ng/ml) markedly decreased ETA receptor mRNA levels. In both LGC and LTC there was an inverse relationship between ETA receptor gene expression and progesterone production; insulin (in LGC) and forskolin (in LTC) enhanced progesterone production while inhibiting ETA receptor mRNA levels. Our findings may therefore suggest that, during early stages of luteinization when peak levels of both LH and insulin-like growth factor I exist, the expression of ETA receptors in the gland are suppressed. This study demonstrates physiologically relevant regulatory mechanisms controlling ETA receptor gene expression and further supports the inhibitory role of ET-1 in CL function.

The effect of low-to-moderate-dose ethanol consumption on rat mammary gland structure and function and early postnatal growth of offspring

2013 ◽  
Vol 304 (10) ◽  
pp. R791-R798 ◽  
Author(s):  
Megan E. Probyn ◽  
Emma-Kate Lock ◽  
Stephen T. Anderson ◽  
Sarah Walton ◽  
John F. Bertram ◽  
...  
Keyword(s):  
Mammary Gland ◽  
Alcohol Consumption ◽  
Milk Proteins ◽  
Postnatal Growth ◽  
Whey Acidic Protein ◽  
Acidic Protein ◽  
Postnatal Life ◽  
Sprague Dawley ◽  
Moderate Dose ◽  
Protein Levels

High levels of alcohol consumption during pregnancy can lead to growth deficits in early postnatal life. However, the effects of low-to-moderate alcohol consumption during pregnancy are less clearly defined. The aim of this study was to determine whether low-to-moderate ethanol (EtOH) consumption throughout pregnancy in the rat alters maternal mammary gland morphology and milk protein levels, thereby affecting lactation and the growth of pups after birth. Sprague-Dawley rats were fed an ad libitum liquid diet ± 6% vol/vol EtOH throughout pregnancy. Mammary glands from dams were collected at embryonic day (E) 20 or postnatal day (PN) 1, and expression of milk proteins (α-lactalbumin, β-casein, and whey acidic protein) was examined. In addition, relative amounts of alveoli, lactiferous ducts, adipose tissue, and blood vessels were determined at PN1. A subset of rats gave birth, and offspring growth and milk intake were recorded. Mammary gland weight was unaltered by EtOH, and stereological analysis showed no differences in gland structure compared with control. Although there were no significant changes in mammary gland gene expression at the RNA level, protein levels of α-lactalbumin were increased and whey acidic protein were decreased by EtOH. Offspring of EtOH-fed dams consumed less milk than controls in the lactational period; however, this did not alter their early postnatal growth. Overall, it appears that low-to-moderate-dose prenatal EtOH exposure does not significantly alter mammary gland development but may alter the composition of the various proteins found within the milk in a manner that maintains overall pup growth.

Developmental expression of pIgR gene in sheep mammary gland and hormonal regulation

2002 ◽  
Vol 69 (1) ◽  
pp. 13-26 ◽  
Author(s):  
AURORE RINCHEV-ALARNOLD ◽  
LUCETTE BELAIR ◽  
JEAN DJIANE
Keyword(s):  
Gene Expression ◽  
Mammary Gland ◽  
Hormonal Regulation ◽  
Mrna Level ◽  
Immunohistochemical Analysis ◽  
Developmental Expression ◽  
Secretory Iga ◽  
Mrna Levels ◽  
Immunoglobulin Receptor ◽  
Pregnancy And Lactation

Secretory IgA found in external secretions are constituted by polymeric IgA (pIgA) bound to the extra-cellular part of the polymeric immunoglobulin receptor (pIgR). The receptor mediates transcytosis of pIgA across epithelial cells. The aim of the present study was to analyse the evolution of pIgR expression in the sheep mammary gland during the development of the mammary gland and to analyse its hormonal regulation. Gene expression of the pIgR was analysed in sheep mammary gland during pregnancy and lactation. By Northern Blot analysis, we observed that low levels of pIgR mRNA are expressed until day 70 of pregnancy. Accumulation of pIgR mRNA started during the third part of pregnancy and intensified 3 d after parturition to reach highest levels during established lactation (day 70). In situ hybridization analysis was used to confirm the increase in pIgR gene expression per mammary epithelial cell. In order to examine the hormonal regulation of the pIgR expression, virgin ewes were hormonally treated. Treatment with oestradiol and progesterone increased pIgR mRNA levels slightly. Subsequent addition of glucocorticoids induced a significant accumulation of pIgR mRNA in the mammary gland of the treated animals. Immunohistochemical analysis was performed to verify that the increase of pIgR mRNA level was associated with enhancement of the pIgR protein in mammary cells. No increase of pIgR mRNA levels were observed if PRL secretion was blocked by bromocryptine injections throughout the hormonal procedure. In conclusion, the present experiments suggest that the enhancement of pIgR levels during lactation result from combined effects of both prolactin and glucocorticoids.

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