B. Zavizion et al., SUBCLONING THE MAC-T BOVINE MAMMARY EPITHELIAL-CELL LINE - MORPHOLOGY, GROWTH-PROPERTIES, AND CYTOGENETIC ANALYSIS OF CLONAL CELLS, Journal of dairy science, 78(3), 1995, pp. 515-527
The objectives of the present study were 1) to determine the heterogen
eity 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 cha
racteristics, beta-casein production, response to oxytocin, and cytoge
netic properties of the clones. Three clonal cells, designated CU-1, C
U-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 contai
ned 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 c
ells. 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-f
ree medium. MAC-T cells and clones constitutively expressed beta-casei
n in culture ranging from .1 to .3 mu g/ml per 24 h. Cytogenetic analy
ses revealed Robertsonian translocations and isochromosomes in the clo
nal lines. We conclude that parental MAC-T cells are heterogeneous in
morphology, growth, and cytogenetic characteristics.