Subcloning the MAC-T Bovine Mammary Epithelial Cell Line: Morphology, Growth Properties, and Cytogenetic Analysis of Clonal Cells

Abstract

The objectives of the present study were 1) to determine the heterogeneity of the MAC-T cell line; 2) to examine whether homogeneous clones could be derived from MAC-T cells; and 3) to examine cell morphology, cytoskeletal characteristics, size, colony-forming ability, growth characteristics, beta-casein production, response to oxytocin, and cytogenetic properties of the clones. Three clonal cells, designated CU-1, CU-2, and CU-3, were derived from MAC-T cells. CU-1 and CU-2 cells were morphologically homogeneous. CU-3 cells were heterogeneous and contained two distinct subtypes. All clones contained cytokeratin 14 and 18. CU-2 and CU-3 cells were 30 and 18% larger, respectively, than CU-1 cells. CU-1 cells did not grow in serum-free medium. Doubling times for MAC-T, CU-2, and CU-3 were 46, 48, and 78 h, respectively, in serum-free medium. MAC-T cells and clones constitutively expressed beta-casein in culture ranging from .1 to .3 micrograms/ml per 24 h. Cytogenetic analyses revealed Robertsonian translocations and isochromosomes in the clonal lines. We conclude that parental MAC-T cells are heterogeneous in morphology, growth, and cytogenetic characteristics.

Milk Protein Synthesis in the Lactating Mammary Gland: Insights from Transcriptomics Analyses

“…Bovine mammary epithelial MAC-T cell line cultured on plastic expresses and releases a low amount of casein into the media [125,126]; however, the amount released is often below the limit of detection [127]. When MAC-T cells are cultivated on a floating collagen gel the expression and production of casein is augmented dramatically [127].…”

A Proteomic Analysis of Differentiation in the Mammary Epithelium

“…Additionally, CK18 and had previously been demonstrated to be uniformly expressed by MAC-T populations (Zavizion, 1995).…”

Cytogenetic and Molecular Characterization of Y Isochromosome in a 63XO/64Xi(Yq) Mosaic Karyotype of an Intersex Horse

“…Autosomal isochromosomes have been observed in canine tumors Tap et al, 1998], some bovine cell lines [Kopp et al, 1992;Schnurr et al, 1994;Zavizion et al, 1995], and in a horse ( Equus caballus , ECA) where the formation of i(26q) resulted in ECA26 trisomy [Bowling and Millon, 1990]. In contrast to humans, i(Xq) has been described only in an infertile 64,Xi(Xq) filly [Mäkelä et al, 1994].…”