Figure 4
From: Conservation and evolutionary divergence in the activity of receptor-regulated smads
NvSmad2 induces expression of downstream Activin/Nodal pathway genes in Xenopus . Animal caps injected with XSmad2, XSmad3, dSmad2, or NvSmad2 mRNA at the two-cell stage show elevated expression of genes downstream of the Activin/Nodal pathway. (A) Western blot showing tagged protein translation levels in injected and uninjected whole embryos (L = Benchmark protein ladder, showing the 58-kDa band). XSmad2, XSmad3, NvSmad2/3, and dSmad2 show equal levels of translation, whereas uninjected embryos show no background signal. Real-time quantitative PCR (RT-PCR) shows fold induction levels of Activin/Nodal pathway members on the Y-axis. (B) Class I markers goosecoid and anti-dorsalizing morphogenetic protein (ADMP). (C) Class II markers chordin, noggin, follistatin, and eomesodermin. (D) Class III markers mixer, mix.2, and sox17α. (E) Class IV marker Xbra. (F) Xbra induction response to 2 ng, 5 ng, and 10 ng XSmad2 or NvSmad2/3. See text for discussion of marker classes.