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Figure 2. Specific Inhibition of Mesodermal Differentiation by XFDL(A) q-PCR analysis for Xbra (top), Mix.2 (middle), and Sox17α (bottom) expression. The four animal blastomeres at the 8-cell stage were injected with control mRNA (400 pg/cell; lanes 1 and 2) or 100 pg/cell (lane 3), 200 pg/cell (lane 4), or 400 pg/cell (lane 5) of XFDL mRNA. Animal caps (excised at stage 8.5) were then cultured without (lane 1) or with 5 ng/ml Activin (lanes 2–5) until siblings reached stage 11.(B) q-PCR analysis for Sox2 expression. Chordin (50 pg/cell; lanes 2–5) and increasing amounts of XFDL mRNAs were coinjected and analysis was performed as in (A).(C–R) In situ hybridization analysis of the embryos injected with XFDL mRNA. Control embryos (C, E, G, I, K, M, O, and Q) or embryos given XFDL mRNA (400 pg/cell) by injection at the 4-cell stage (D, F, H, J, L, N, P, and R) were harvested at stage 10.5 (C–L and O–R) or stage 11.5 (M and N) and analyzed by the indicated probes. Arrowheads, the dorsal and ventral blastopore lips; bracket, the marginal zone (see Xbra expression in panel C).(S and T) Embryos injected with SalF (400 pg/cell; S) or Tsh3 (400 pg/cell; T) were analyzed at stage 10.5 by in situ hybridization using the Xbra probe. |
