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Role of ovarian secretions in mammary gland development and function in ruminants*

Published online by Cambridge University Press:  08 October 2013

L. Yart ,
V. Lollivier ,
P. G. Marnet  and
F. Dessauge
L. Yart
Affiliation:
INRA, UMR1348 Pegase, F-35590 Saint-Gilles, France Agrocampus Ouest, UMR1348 Pegase, F-35000 Rennes, France
V. Lollivier
Affiliation:
INRA, UMR1348 Pegase, F-35590 Saint-Gilles, France Agrocampus Ouest, UMR1348 Pegase, F-35000 Rennes, France
P. G. Marnet
Affiliation:
INRA, UMR1348 Pegase, F-35590 Saint-Gilles, France Agrocampus Ouest, UMR1348 Pegase, F-35000 Rennes, France
F. Dessauge*
Affiliation:
INRA, UMR1348 Pegase, F-35590 Saint-Gilles, France Agrocampus Ouest, UMR1348 Pegase, F-35000 Rennes, France
*
†E-mail: [email protected]
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Abstract

The mammary gland is a dynamic organ that undergoes cyclic developmental and regressive changes during the lifetime of a female mammal. Mammogenesis begins during embryonic life with the development of the first mammary gland rudiments and ductal system. After birth, during the pre-pubertal period, the ductal growth of the mammary parenchyma occurs through the fat pad. In most of the ruminant species allometric mammary parenchyma development begins with the onset of cyclic ovarian secretions activity. The two main hormones secreted during an ovarian cycle are estradiol and progesterone. These steroid hormones are derived from cholesterol and are synthesized by theca and granulosa cells in ovaries. During puberty, the mammary parenchyma develops in a compact, highly arborescent parenchymal mass surrounded by a dense connective matrix. Ductal elongation and lobulo-alveolar development are accomplished during growth and pregnancy to prepare for future milk production. At the end of lactation, the mammary gland undergoes involution, which corresponds to a regression of the secretory tissue, a reduction in the alveolar size and a loss of mammary epithelial cells (MECs). Ovarian steroids (estradiol and progesterone) appear to be key regulators of the different stages of mammogenesis and mammary function. Through this review, the role and the importance of ovarian steroids on mammary gland and on MECs is described.

Keywords

mammary glandovarylactationmammary epithelial cellssteroids
Type
Full Paper
Information
animal , Volume 8 , Issue 1 , January 2014 , pp. 72 - 85
Copyright
Copyright © The Animal Consortium 2013 

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Footnotes

*

This review comes from the 63rd European Federation of Animal Science EAAP Annual Meeting, Bratislava, Slovak Republic, 27–31 August 2012.

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