XB-IMG-80977
Xenbase Image ID: 80977
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Fig. S7. BMP/pSMAD1 signaling is upregulated in Osr1/2-depleted embryos and temporal Smad1 overexpression can inhibit lung specification. (A) Immunofluorescence analysis of phospho-SMAD1/5/8 (green) and fibronectin (red) at stage35/36 in Osr1/2-MO bilaterally injected embryos. Section 1 through the foregut is anterior to section 2. Yellow arrows indicate ectopic pSMAD1/5/8 in dorsal foregut endoderm, and yellow asterisks indicate ectopic pSMAD1/5/8 and reduced fibronectin at the level of the nascent lung buds. (B) Embryos were injected with RNA encoding a hormone-inducible GR-Smad1 (800 pg) at the four/eight-cell stage into 1 side of the embryo. Between stages 25 and 35, embryos were treated with or without 1 µM dexamethasone (dex) to activate the construct, thus inducing active BMP signaling. In situ hybridization at stage 35 shows that activated GR-Smad1 is inhibitory to wnt2b, nkx2.1 and sox2 expression. (C) Overexpression of GR-SMAD1 does not cause cell death. Embryos were injected and treated as in B, and analyzed at stage 35/36 by immunofluorescence for Sox2 (red) and activated caspase 3 (green). No cell death was detectable in either condition. (D) LDN treatment rescues the elevated pSMAD1/5/8 signaling observed in Osr1/2-MO embryos. Embryos were injected as in A and treated from stages 25-35 with DMSO vehicle or 10 µM LDN193189 and assayed by immunofluorescence for phospho-SMAD1/5/8 (green). Image published in: Rankin SA et al. (2012) Copyright © 2012. Image reproduced on Xenbase with permission of the publisher and the copyright holder. This is an Open Access article distributed under the terms of the Creative Commons Attribution License. Larger Image Printer Friendly View |
