scholarly journals The miR-200 family in normal mammary gland development

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Majesta J. Roth ◽  
Roger A. Moorehead
Keyword(s):  
Mammary Tumor ◽  
Mammalian Species ◽  
Late Pregnancy ◽  
Mammary Glands ◽  
Mammary Development ◽  
Normal Mammary Gland ◽  
Ductal Morphogenesis ◽  
Mammary Tumor Growth ◽  
Pregnancy And Lactation ◽  
The Impact

AbstractThe miR-200 family of microRNAs plays a significant role in inhibiting mammary tumor growth and progression, and its members are being investigated as therapeutic targets. Additionally, if future studies can prove that miR-200s prevent mammary tumor initiation, the microRNA family could also offer a preventative strategy. Before utilizing miR-200s in a therapeutic setting, understanding how they regulate normal mammary development is necessary. No studies investigating the role of miR-200s in embryonic ductal development could be found, and only two studies examined the impact of miR-200s on pubertal ductal morphogenesis. These studies showed that miR-200s are expressed at low levels in virgin mammary glands, and elevated expression of miR-200s have the potential to impair ductal morphogenesis. In contrast to virgin mammary glands, miR-200s are expressed at high levels in mammary glands during late pregnancy and lactation. miR-200s are also found in the milk of several mammalian species, including humans. However, the relevance of miR-200s in milk remains unclear. The increase in miR-200 expression in late pregnancy and lactation suggests a role for miR-200s in the development of alveoli and/or regulating milk production. Therefore, studies investigating the consequence of miR-200 overexpression or knockdown are needed to identify the function of miR-200s in alveolar development and lactation.

ANALYSIS OF RIBOSOMES AND POLYSOMES DERIVED FROM RABBIT MAMMARY GLANDS DURING PREGNANCY AND LACTATION

1971 ◽  
Vol 49 (4) ◽  
pp. 667-NP ◽  
Author(s):  
I. D. HERRIMAN ◽  
G. D. BAIRD ◽  
JUDY M. BRUCE
Keyword(s):  
Electron Microscopy ◽  
Density Gradient ◽  
Gradient Analysis ◽  
Late Pregnancy ◽  
Sucrose Density Gradient ◽  
Mammary Glands ◽  
Pregnancy And Lactation

SUMMARY Whole-ribosome and polysome-enriched fractions were prepared from the mammary glands of rabbits during late pregnancy and lactation. The composition of the fractions was determined by sucrose density gradient analysis and electron microscopy. The range of size of polysomal aggregates was similar in the late-pregnant and lactating gland, with aggregates containing five to nine ribosomal units predominating. However, the amount of polysomes relative to monosomes was invariably found to increase after parturition. The greater portion of this increase was accounted for by the increased abundance of aggregates containing five to nine units.

scholarly journals Maternal Metabolic Demands Caused by Pregnancy and Lactation: Association with Productivity and Offspring Phenotype in High-Yielding Dairy Ewes

Animals ◽  
2019 ◽  
Vol 9 (6) ◽  
pp. 295 ◽  
Author(s):  
José Luis Pesántez-Pacheco ◽  
Ana Heras-Molina ◽  
Laura Torres-Rovira ◽  
María Victoria Sanz-Fernández ◽  
Consolación García-Contreras ◽  
...  
Keyword(s):  
Milk Yield ◽  
Body Condition Score ◽  
Late Pregnancy ◽  
Productive Performance ◽  
Multiple Pregnancies ◽  
Dairy Sheep ◽  
Condition Score ◽  
Pregnancy And Lactation ◽  
The Impact ◽  
Singleton Pregnancies

Pregnancy and lactation, especially when concurrent, create a rather metabolically demanding situation in dairy ruminants, but little is known about their effects on offspring phenotype and milk yield. Here, we evaluated the impact of pregnancy and lactation on the metabolic traits and productive performance of Lacaune dairy sheep and their offspring. Productive performance was measured in terms of milk yield, body weight (BW), body condition score (BCS), and size. Productivity was assessed during mid-pregnancy (75 ± 5 d) and late pregnancy (142 ± 4 d) and at 52 ± 5 d in the postpartum period. During pregnancy, high-yielding ewes had higher BW, BCS, plasma glucose, cholesterol, β-OHB, and NEFA than low-yielding ewes, but lower levels of lactate and urea. High-yielding animals had lower BCS after lambing, but their lambs showed greater growth. Productivity during lactation was affected by ewe age and parity: Mature ewes (but not maiden sheep) whose BCS increased steeply during pregnancy yielded more milk in the subsequent lactation than those whose BCS did not increase. Lamb BW and size were positively associated with milk yield in the subsequent lactation. Mature ewes had higher yields than maiden sheep, and mature ewes with multiple pregnancies produced more milk than those with singleton pregnancies. Ewes with male singleton pregnancies also showed higher yield than those with female singletons. These results demonstrate that high-yielding dairy sheep, when appropriately fed and managed, can adequately cover the metabolic demands of pregnancy and high milk production (even when concurrent) without losing productivity.

ENZYMES OF LACTOSE BIOSYNTHESIS IN NORMAL AND HORMONALLY STIMULATED RABBIT MAMMARY GLANDS

1968 ◽  
Vol 40 (1) ◽  
pp. 81-84 ◽  
Author(s):  
R. J. HEITZMAN
Keyword(s):  
Enzyme Activities ◽  
Deoxyribonucleic Acid ◽  
Late Pregnancy ◽  
Mammary Glands ◽  
Uridine Diphosphate ◽  
Early Lactation ◽  
Uridine Diphosphate Glucose ◽  
Pregnancy And Lactation ◽  
Diphosphate Glucose ◽  
The Difference

SUMMARY The activities of uridine diphosphate glucose (UDPG) pyrophosphorylase and UDPG-4′-epimerase in mammary glands of rabbits were determined in late pregnancy and lactation. The activities in animals during the last 4 days of pregnancy and during days 0–4, 5–9 and 11–21 of lactation increased but the difference in the activities was significant between the days 5–9 and 11–21 only and for the pyrophosphorylase activity between days for 0–4 and 5–9. Prolactin and cortisol acetate given daily for 3 or 5 days to rabbits pseudopregnant for 15 days caused increases in enzyme activities that were several times greater than those found in controls. The enzyme activities in the stimulated glands were similar to those observed in early lactation. The levels of deoxyribonucleic acid/g. wet tissue were the same in the stimulated and lactating glands.

scholarly journals 431 Increasing IGF-1 concentrations in late pregnancy stimulates mammary development of gilts

2019 ◽  
Vol 97 (Supplement_3) ◽  
pp. 137-137
Author(s):  
Chantal Farmer ◽  
Pieter Langendijk
Keyword(s):  
Dry Matter ◽  
Late Pregnancy ◽  
Mammary Glands ◽  
Mammary Development ◽  
Sterile Water ◽  
Tissue Composition ◽  
Blood Concentrations ◽  
Blood Samples ◽  
Dna And Rna ◽  
Porcine Somatotropin

Abstract The goal of this project was to determine if increasing insulin-like growth factor-1 (IGF-1) concentrations in late pregnancy can stimulate mammogenesis in gilts. Yorkshire x Landrace gilts (196.2 ± 6.2 kg BW on day 89 of gestation) were separated in two groups: 1) controls (CTL, n = 17) injected with sterile water, and 2) porcine somatotropin-treated (pST, n = 20) injected daily with 5 mg of pST (Reporcin®) from days 90 to 109 of gestation. Gilts were slaughtered on day 110 to collect mammary glands and blood samples were obtained on days 89, 96, 103 and 109 of gestation. Treated gilts gained more BW (P < 0.05) and lost more backfat (P < 0.05) than CTL gilts during treatment. There was a treatment x day effect (P < 0.01) on IGF-1, glucose and urea concentrations in blood. Concentrations of IGF-1 increased fourfold (P < 0.01) in pST compared with CTL gilts on days 96, 103 and 109 of gestation. Insulin values were also greater on days 96 (P < 0.01) and 103 (P = 0.01), and tended to be greater (P < 0.10) on day 109 of gestation in pST gilts. Glucose was greater in pST than CTL gilts on days 96 (P < 0.01), 103 (P < 0.01) and 109 (P = 0.01). Injections of pST did not affect weight of mammary extraparenchyma (P > 0.10) but increased mammary parenchymal mass (1922.2 vs 1576.1 ± 123.9 g, P < 0.05). Mammary parenchyma contained more (P < 0.05) protein, DNA and RNA and less fat (P < 0.05) and dry matter (P < 0.01) in pST than CTL gilts. These findings demonstrate that increasing circulating IGF-1 in late-pregnant gilts can stimulate mammary development both in terms of total parenchymal mass and of parenchymal tissue composition.

Ultrasonographic assessment of the feline mammary gland

2008 ◽  
Vol 10 (5) ◽  
pp. 466-471 ◽  
Author(s):  
Rita Payan-Carreira ◽  
Ana C. Martins-Bessa
Keyword(s):  
Mammary Gland ◽  
Diagnostic Tool ◽  
Late Pregnancy ◽  
Mammary Glands ◽  
Mammary Tissue ◽  
Physiological Changes ◽  
Linear Transducer ◽  
Pregnancy And Lactation ◽  
Ultrasonographic Assessment ◽  
Ultrasonographic Appearance

The aim of this study is to characterise the feline mammary echotexture using B-mode ultrasonography, which is not routinely used to examine the feline mammary gland. Using a 5–9 MHz linear transducer the ultrasonographic appearance of non-stimulated and stimulated mammary glands was determined in 35 mature intact non-pregnant, pregnant and lactating queens aged from 16 months to 8 years. In intact non-pregnant queens, mammary glands are fairly underdeveloped and on the ultrasonograms they appear with a regular hypoechoic texture and generally show a thickness of less than 2.0 mm. The stimulated mammary tissue typically presents a more hyperechoic appearance compared to the non-stimulated gland and a fine granular echotexture. Maximum echogenicity of the mammary gland is reached during lactation. In late pregnancy, the mammary glands reach 6–9 mm in thickness. During lactation, the size of the glands depends on the existence of a suckling stimulus, with the suckled glands reaching about 11 mm in thickness. Ductal structures can only be imaged during late pregnancy and lactation. Ultrasonographic evaluation of the feline mammary gland can become a valuable diagnostic tool to characterise physiological changes and may further contribute to a better characterisation of diseased mammary tissue.

scholarly journals The Homeodomain Protein CDP Regulates Mammary-Specific Gene Transcription and Tumorigenesis

2004 ◽  
Vol 24 (11) ◽  
pp. 4810-4823 ◽  
Author(s):  
Quan Zhu ◽  
Urmila Maitra ◽  
Dennis Johnston ◽  
Mary Lozano ◽  
Jaquelin P. Dudley
Keyword(s):  
Mammary Tumor ◽  
Mammary Glands ◽  
Mammary Development ◽  
Mutant Mice ◽  
Specific Gene ◽  
Homeodomain Protein ◽  
Wild Type ◽  
Viral Spread ◽  
Specific Regulation ◽  
Rna Levels

ABSTRACT The CCAAT-displacement protein (CDP) has been implicated in developmental and cell-type-specific regulation of many cellular and viral genes. We previously have shown that CDP represses mouse mammary tumor virus (MMTV) transcription in tissue culture cells. Since CDP-binding activity for the MMTV long terminal repeat declines during mammary development, we tested whether binding mutations could alter viral expression. Infection of mice with MMTV proviruses containing CDP binding site mutations elevated viral RNA levels in virgin mammary glands and shortened mammary tumor latency. To determine if CDP has direct effects on MMTV transcription rather than viral spread, virgin mammary glands of homozygous CDP-mutant mice lacking one of three Cut repeat DNA-binding domains (ΔCR1) were examined by reverse transcription-PCR. RNA levels of endogenous MMTV as well as α-lactalbumin and whey acidic protein (WAP) were elevated. Heterozygous mice with a different CDP mutation that eliminated the entire C terminus and the homeodomain (ΔC mice) showed increased levels of MMTV, β-casein, WAP, and α-lactalbumin RNA in virgin mammary glands compared to those from wild-type animals. No differences in amounts of WDNM1, ε-casein, or glyceraldehyde-3-phosphate dehydrogenase RNA were observed between the undifferentiated mammary tissues from wild-type and mutant mice, indicating the specificity of this effect. These data show independent contributions of different CDP domains to negative regulation of differentiation-specific genes in the mammary gland.

scholarly journals Polyamine biogenesis in the rat mammary gland during pregnancy and lactation

1972 ◽  
Vol 130 (1) ◽  
pp. 71-76 ◽  
Author(s):  
Diane H. Russell ◽  
Thomas A. McVicker
Keyword(s):  
Mammary Gland ◽  
Late Pregnancy ◽  
Normal Mammary Gland ◽  
Biosynthetic Activity ◽  
A Value ◽  
Lactating Mammary Gland ◽  
Pregnancy And Lactation ◽  
Rat Mammary Gland ◽  
Gland Development ◽  
Very High

Polyamines and RNA accumulate in the rat mammary gland during pregnancy, but the major increases occur after parturition. Therefore the major increases occur after the gland has obtained its maximal complement of epithelial cells. During lactation, the spermidine concentration rises above 5mm and RNA content in the lactating mammary gland reaches a value 16 times that of the unstimulated mammary gland. The ratio of spermidine/spermine, an increase of which initially signals an elevation in biosynthetic activity, is near 1 in the normal mammary gland and is greater than 10 in the lactating mammary gland. Putrescine concentration is very low during the entire course of mammary-gland development, with the exception of early pregnancy. The low putrescine concentration probably reflects the very rapid conversion of putrescine into spermidine. Both ornithine decarboxylase, the enzyme that synthesizes putrescine, and putrescine-stimulated S-adenosyl-l-methionine decarboxylase, the enzyme that synthesizes spermidine, increase in activity during middle and late pregnancy; during lactation, both enzyme activities are elevated until the 21st day of lactation, and then decline. These declines are concomitant with involution. Also, it was found that the amount of ribonuclease activity in the mammary gland was very high during lactation, almost double that in the gland during pregnancy.

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