(A) Interaction between xBcl-2 and xBax changes at
the MBT. Embryos were injected at the one-cell stage with a mixture of
FLAG-tagged xBcl-2 and c-myc-tagged xBax mRNAs. The
embryos were not irradiated (control) or were irradiated 3 h
(stage 6) or 7 h (stage 9) after fertilization, collected at
different times, and frozen. Samples equivalent to five embryos were
immunoprecipitated with anti-FLAG M2-agarose beads, and the
immunocomplexes were subjected to Western blot analysis with
anti-c-myc antibody. (B) Analysis of xBax
homodimerization. Embryos were injected at the one-cell stage with
FLAG-tagged and c-myc-tagged xBax mRNAs, were not
irradiated (control) or were irradiated at either stage 6
(I) or stage 9 (II), and were collected
at different times. Samples equivalent to five embryos were
immunoprecipitated with anti-c-myc-agarose beads, and
the immunocomplexes were blotted with anti-FLAG M2 antibody (I,
Top, and II, Top). Total FLAG-xBcl-2, FLAG-xBax,
and c-myc-xBax expression levels were assessed at all
stages by Western blotting with specific anti-tag antibodies
(A and B, I and
II, Middle and Bottom).
Arrows on the right denote the FLAG-tagged or
c-myc-tagged protein.