Spemann
Mostrando 13-17 de 17 artigos, teses e dissertações.
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13. Transcriptional regulation of the Xlim-1 gene by activin is mediated by an element in intron I
The Xlim-1 gene is activated in the late blastula stage of Xenopus embryogenesis in the mesoderm, and its RNA product becomes concentrated in the Spemann organizer at early gastrula stage. A major regulator of early expression of Xlim-1 is activin or an activin-like signal. We report experiments aiming to identify the activin response element in the Xl
National Academy of Sciences.
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14. Wnt signaling and transcriptional control of Siamois in Xenopus embryos
The Wnt-inducible homeobox gene Siamois is expressed in Xenopus embryos before gastrulation and is necessary for formation of the Spemann organizer. Here we show that 5′-flanking sequences of the Siamois coding region can specifically activate a heterologous reporter gene in dorsovegetal cells, thus mimicking Siamois’s endogenous expression. A 245-bp DNA
The National Academy of Sciences.
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15. Wnt antagonism initiates cardiogenesis in Xenopus laevis
Heart induction in Xenopus occurs in paired regions of the dorsoanterior mesoderm in response to signals from the Spemann organizer and underlying dorsoanterior endoderm. These tissues together are sufficient to induce heart formation in noncardiogenic ventral marginal zone mesoderm. Similarly, in avians the underlying definitive endoderm induces cardiogenes
Cold Spring Harbor Laboratory Press.
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16. Xenopus as a model system to study transcriptional regulatory networks
Development is controlled by a complex series of events requiring sequential gene activation. Understanding the logic of gene networks during development is necessary for a complete understanding of how genes contribute to phenotype. Pioneering work initiated in the sea urchin and Drosophila has demonstrated that reasonable transcriptional regulatory network
National Academy of Sciences.
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17. Cooperation between the activin and Wnt pathways in the spatial control of organizer gene expression
The normal expression pattern of the Wnt responsive homeobox gene Siamois is restricted to the dorso-vegetal region of the Xenopus embryo. Because the Wnt signaling pathway (via β-catenin) is active on the entire dorsal side of the early embryo, we have asked why Siamois expression is not seen in the dorsal ectoderm. Only Wnt signaling, via activation of β
The National Academy of Sciences.