Effect of transient β-estradiol treatment on
E26–βER-transformed MEP clones. (A) Experimental
protocol. Cells were treated for 1–4 days with β-estradiol,
thoroughly washed, and incubated in the absence of the hormone for a
total of 8 days, at which time they were subjected to FACS analysis.
Changes in MEP21 (B), EOS47 (C), and
MYL51/2 (D) expression in MEP clones transformed
by E26–WT and E26–βER after transient exposure to β-estradiol
for 1–4 days (as indicated) were determined by antibody staining and
FACS analysis at day 8 after initiation of the experiment. (Black line)
E26–WTcl.1; (blue line) E26–βERcl.1; (red line) E26–βERcl.2.
(E) May–Gruenwald–Giemsa (left) and peroxidase
staining (right) of untreated E26–βER cl.1 cells
(a,b), or cells treated for 1 day (c,d), or 2 days
(e,f) with β-estradiol. Note that 30% of the cells in
c and d are EOS47 positive.