Modulation of STAT5 activity does not correlate with altered BMP signaling. Shown are representative embryos processed by whole mount in situ hybridization at stage 10.5 for the dorsal-anterior mesoderm marker xChordin (left column panels), the Spemann Organizer marker xGoosecoid (middle column panels), or the ventral-posterior marker Xvent-1 (right column panels). All embryos are shown with a dorsal lip view, anterior at the top. Embryos were injected with EF-1α as a control (top row) or had been injected with RNA encoding STAT5-EnR (middle row) or STAT5-VP16 (bottom row), as indicated. The white arrows point out the normal expression domains for these early markers (seen in this experiment for the majority of at least 12 embryos). As indicated by the black arrows, STAT5-VP16 reduces modestly the expression levels for both xGoosecoid (seen in this experiment for 7 of 12 embryos) and Xvent-1 (seen in this experiment for 10 of 16 embryos) but not xChordin (13 embryos).