The Sox axis, Nodal signaling, and germ layer specification

Zhang, Chi; Klymkowsky, Michael W.

doi:10.1111/j.1432-0436.2007.00190.x

Cited by 34 publications

(37 citation statements)

References 89 publications

(175 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…These authors also found that Sox3 was able to repress expression of the Nodal family member cyc in zebrafish (Zhang et al, 2004;Zhang and Klymkowsky, 2007).…”

Section: Introductionmentioning

confidence: 74%

SoxB1 transcription factors restrict organizer gene expression by repressing multiple events downstream of Wnt signalling

et al. 2010

View full text Add to dashboard Cite

SUMMARYFormation of the organizer is one of the most central patterning events in vertebrate development. Organizer-derived signals are responsible for establishing the CNS and patterning the dorsal ventral axis. The mechanisms promoting organizer formation are known to involve cooperation between Nodal and Wnt signalling. However, the organizer forms in a very restricted region, suggesting the presence of mechanisms that repress its formation. Here, we show in zebrafish that the transcription factor Sox3 represses multiple steps in the signalling events that lead to organizer formation. Although -catenin, Bozozok and Squint are known to play major roles in establishing the dorsal organizer in vertebrate embryos, overexpression of any of these is insufficient to induce robust expression of markers of the organizer in ectopic positions in the animal pole, where Sox3 is strongly expressed. We show that a dominant-negative nuclear localisation mutant of Sox3 can cause ectopic expression of organizer genes via a mechanism that activates all of these earlier factors, resulting in later axis duplication including major bifurcations of the CNS. We also find that the related SoxB1 factor, Sox19b, can act redundantly with Sox3 in these effects. It therefore seems that the broad expression of these SoxB1 genes throughout the early epiblast and their subsequent restriction to the ectoderm is a primary regulator of when and where the organizer forms.

show abstract

“…These authors also found that Sox3 was able to repress expression of the Nodal family member cyc in zebrafish (Zhang et al, 2004;Zhang and Klymkowsky, 2007).…”

Section: Introductionmentioning

confidence: 74%

SoxB1 transcription factors restrict organizer gene expression by repressing multiple events downstream of Wnt signalling

et al. 2010

View full text Add to dashboard Cite

show abstract

“…For example, ectodermin is maternally expressed and localized to the animal pole in Xenopus, thus creating a zone that is less responsive to Nodal and BMP signals (Dupont et al 2005;Dupont et al 2009). Additional transcription factors such as Sox3, Xema/FoxI1e, Serum response factor, and XFDL156, and the Cerberus-like protein Coco are also expressed in presumptive ectoderm and protect ectoderm from Nodal inducers (Bell et al 2003;Suri et al 2005;Mir et al 2007;Yun et al 2007;Zhang and Klymkowsky 2007;Sasai et al 2008). Thus, prepatterning will modulate the generation of and response to Nodal signaling gradients.…”

Section: Discussionmentioning

confidence: 99%

Nodal Morphogens

Schier

2009

Cold Spring Harbor Perspectives in Biology

255

290

View full text Add to dashboard Cite

Nodal signals belong to the TGF-b superfamily and are essential for the induction of mesoderm and endoderm and the determination of the left-right axis. Nodal signals can act as morphogens-they have concentration-dependent effects and can act at a distance from their source of production. Nodal and its feedback inhibitor Lefty form an activator/inhibitor pair that behaves similarly to postulated reaction-diffusion models of tissue patterning. Nodal morphogen activity is also regulated by microRNAs, convertases, TGF-b signals, coreceptors, and trafficking factors. This article describes how Nodal morphogens pattern embryonic fields and discusses how Nodal morphogen signaling is modulated.

show abstract

“…Mesoderm has been termed a "secondary" germ layer, since it arises early in embryogenesis through inductive interactions between maternal ectodermal and endodermal determinants. 2,3 In that light, neural crest might well be considered a "tertiary" germ layer, since its induction depends upon mesoderm, which acts on ectoderm to induce the *Correspondence to: Kristin Bruk Artinger; Email: Kristin.Artinger@ucdenver.edu Submitted: 05/03/10; Accepted: 07/09/10 Previously published online: www.landesbioscience.com/journals/celladhesion/article/12962 DOI: 10.4161/cam. 4.4.12962 The neural crest is an evolutionary adaptation, with roots in the formation of mesoderm.…”

Section: "Ectoderm and Endoderm Are Primary Germ Layers; They Were Thmentioning

confidence: 99%

“…22,69,70 the expression of Nodal-type TGFb family secreted proteins, while animally localized B1-Sox proteins, as well as other factors, such as Ectodermin, 54 Coco 55,56 and Xema, 57 all targets of Sox3 regulation, act to restrict the extent of Nodal signaling. 3 This VegT/Nodal cascade leads to the zygotic expression of a number of genes, among which are those that encode the T-box transcription factors Eomesodermin, 58 Brachyury (there are in fact three distinct brachyury genes in Xenopus), 59-61 the zygotic splice variant of VegT, known as Antipodean, 62,63 and the T-box transcription factors Tbx6 and Tbx6-related. [64][65][66][67] Recent studies indicate that downregulation of zygotic VegT/Antipodean is We have indicated where a number of the genes that are the primary focus of this review are thought to act.…”

Section: Neural Crest Induction and Migration In Xenopusmentioning

confidence: 99%