Isolation and characterization of a bovine blastocyst-derived trophoblastic cell line, BT-1: Development of a culture system in the absence of feedercell
A. Shimada et al., Isolation and characterization of a bovine blastocyst-derived trophoblastic cell line, BT-1: Development of a culture system in the absence of feedercell, PLACENTA, 22(7), 2001, pp. 652-662
We established a trophoblastic cell line, bovine trophoblast-1 (BT-1), deri
ved from in vitro matured and fertilized blastocyst. While several trophobl
astic cell lines have been previously reported using feeder cell, BT-1 coul
d be cultured in the absence of feeder cell. BT-1 was Cultured for more tha
n 18 months (over 75 passage) in the absence of feeder cells, using bovine
endometrial fibroblast-conditioned medium (fibroblast-conditioned medium).
We found that the cell growth was accelerated in fibroblast-conditioned med
ium, In bromodeoxyuridine incorporation analysis, BT-1 cells growth rate in
fibroblast-conditioned medium was about two-fold higher than that in conve
ntional medium. Furthermore, fibroblast-conditioned medium accelerated atta
chment of BT-1 cells to culture dishes following plating. BT-1 showed epith
elial morphology and expressed cytokeratin. During continuous culture, cell
s accumulated fluid under the cell sheet and form dome-like structure that
eventually transformed into free floating vesicles, Reverse transcription p
olymerase chain reaction analysis and immunoblot analysis demonstrated that
BT-1 cells expressed interferon-tau as well as placental lactogcn (PL). Im
munofluorescence analysis demonstrated that a small number of cells were PL
-positive, and these cells were binucleate. The BT-1 trophoblastic cell lin
e could serve as a powerful model system for the study of trophoblast cell
lineage and proliferation. (C) 2001 Harcourt Publishers Ltd.