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Fig. 5. p27Xic1 synergizes with MyoD to promote muscle differentiation.
(A) Embryos were injected in both cells of two-cell stage embryos with MyoD
(100 pg), p27Xic1 (45 pg), p27Xic1 NT (15 pg),
p27Xic1 CT (50 pg), p27Xic1 35-96 (50 pg) or a
combination thereof. Ventral marginal zones dissected from injected embryos at
stage 10 were allowed to develop until parallel embryos reached stage 19 and
analyzed by RT-PCR for expression of muscle actin (MA), myosin heavy chain
(MHC) and ornithine decarboxylase (ODC) as an internal control. (B)
Quantification of the synergistic upregulation of MA by MyoD and
p27Xic1 mutant overexpression in ventral marginal zones. The
relative induction of MA was determined by measuring the incorporated
[32P]dATP and normalizing to ODC. The standard error of the mean
was obtained by performing this typical experiment in triplicate.