influence of extracellular matrix and prolactin on global gene expression profiles of primary bovine mammary epithelial cells in vitro

• Published in: Animal genetics 2010-02, Vol.41 (1), p.55-63
• Main Authors: Riley, L.G, Gardiner-Garden, M, Thomson, P.C, Wynn, P.C, Williamson, P, Raadsma, H.W, Sheehy, P.A
• Format: Article
• Language: English
• Subjects: Animals; Biosynthesis; Cattle; Cell Culture Techniques; Cells, Cultured; Epithelial Cells - metabolism; extracellular matrix; Extracellular Matrix - metabolism; Female; Gene expression; Gene Expression Profiling; Genomics; mammary epithelial cell; Mammary Glands, Animal - cytology; Mammary Glands, Animal - metabolism; Oligonucleotide Array Sequence Analysis; prolactin; Prolactin - metabolism; Rodents
• ISSN: 0268-9146; 1365-2052
• DOI: 10.1111/j.1365-2052.2009.01964.x

An in vitro bovine mammosphere model was characterized for use in lactational biology studies using a functional genomics approach. Primary bovine mammary epithelial cells cultured on a basement membrane, Matrigel, formed three-dimensional alveoli-like structures or mammospheres. Gene expression profiling during mammosphere formation by high-density microarray analysis indicated that mammospheres underwent similar molecular and cellular processes to developing alveoli in the mammary gland. Gene expression profiles indicated that genes involved in milk protein and fat biosynthesis were expressed, however, lactose biosynthesis may have been compromised. Investigation of factors influencing mammosphere formation revealed that extracellular matrix (ECM) was responsible for the initiation of this process and that prolactin (Prl) was necessary for high levels of milk protein expression. CSN3 (encoding κ-casein) was the most highly expressed casein gene, followed by CSN1S1 (encoding αS1-casein) and CSN2 (encoding β-casein). Eighteen Prl-responsive genes were identified, including CSN1S1, SOCS2 and CSN2, however, expression of CSN3 was not significantly increased by Prl and CSN1S2 was not expressed at detectable levels in mammospheres. A number of novel Prl responsive genes were identified, including ECM components and genes involved in differentiation and apoptosis. This mammosphere model is a useful model system for functional genomics studies of certain aspects of dairy cattle lactation.