Subcloning the MAC-T bovine mammary epithelial cell line: morphology, growth properties, and cytogenetic analysis of clonal cells.
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.
Zavizion
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Department of Animal Science, Cornell University, Ithaca, NY 14853, USA.
Gorewit
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RC
Politis
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I
D000818:Animals; D002364:Caseins / Q000096:biosynthesis; D002417:Cattle; D002453:Cell Cycle; D002455:Cell Division; D002460:Cell Line; D048429:Cell Size; D002999:Clone Cells / Q000166:cytology*; D003599:Cytoskeleton / Q000648:ultrastructure; D004847:Epithelial Cells; D005434:Flow Cytometry; D007621:Karyotyping; D007633:Keratins / Q000032:analysis; D008321:Mammary Glands, Animal / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism; D010121:Oxytocin / Q000494:pharmacology
D002364:Caseins; D010121:Oxytocin; D007633:Keratins