XB-IMG-79045
Xenbase Image ID: 79045
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GSK3-resistant Activated Forms of Smad1 Disrupt Segmentation in Xenopus Embryos. (A and B) Immunostainings for myosin light chain showing loss of segmental borders in somites in the injected side (B) of a Xenopus embryo (stage 26), compared to the uninjected side. C2 or C3 blastomeres were injected with 100 pg of hSmad1 resistant to GSK3 phosphorylation [5] and 50 pg of nuclear LacZ mRNA (n = 32/42). (C) In situ hybridizations for the somite marker MyoD shows a disruption of the segmental pattern in Xenopus embryos (stage 30) injected with activated forms of Smad1. Uninjected control embryos express MyoD in the somitic segments in a typical chevron shape (n = 27). Overexpression of Smad1 wild-type mRNA (SWT) does not change this pattern (n = 21). An activated mutant of Smad1 that has phospho-mimetic amino acid substitutions on the C-terminus (the two most c-terminal serines mutated into glutamic acids, designated EVEmutant [5]) displays mild disruptions of the somite pattern (n = 9/12), while the same phospho-mimetic form of Smad1 with an additional mutation in the GSK3-phosphorylation site in the linker (named EVE-GM exhibits strongly impaired segmentation (n = 14/18). Nuclear LacZ marks the injected cells. Image published in: Eivers E et al. (2009) Eivers et al. This image is reproduced with permission of the journal and the copyright holder. This is an open-access article distributed under the terms of the Creative Commons Attribution license
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