Regulation of the early expression of the Xenopus nodal-related 1 gene, Xnr1

Development ◽  
2000 ◽  
Vol 127 (6) ◽  
pp. 1221-1229 ◽  
Author(s):  
C.E. Hyde ◽  
R.W. Old
Keyword(s):  
Binding Sites ◽  
Marginal Zone ◽  
Mutational Analysis ◽  
Promoter Sequence ◽  
Second Phase ◽  
Lateral Plate Mesoderm ◽  
Lateral Plate ◽  
T Box ◽  
Early Expression ◽  
Complex Expression

The Xenopus nodal related-1 (Xnr1) gene has a complex expression pattern in embryos, with two temporal phases. In the first phase, transcripts are first detected in perinuclear sites in the vegetal region of the blastula. During gastrulation, this expression disappears and transcripts become localised to the dorsal marginal zone. Expression stops and then restarts in a second phase at neurula and tailbud stages, firstly in two symmetric patches near the posterior end of the notochord, and then asymmetrically in a large domain in the left lateral plate mesoderm. In this study, we have investigated the regulation of the early phase of expression of Xnr1. We show that the T-box transcription factor VegT can induce Xnr1. It had previously been shown that Xnr1 can induce VegT in ectoderm cells and we show that the early expression of Xnr1 is regulated by an autoregulatory loop. By inspection of the Xnr1 promoter sequence, we have identified two non-palindromic T-box-binding sites, which are 10 bp apart. Using mutational analysis, we have shown that these elements are required for the VegT induction of Xnr1. The Xnr1 promoter shows striking homologies with the Xnr3 promoter. In particular, two elements that are required for Wnt signaling are conserved between these two promoters, but the two T-box sites are not conserved, and Xnr3 is not induced by VegT. A region of the promoter containing the T-box sites and the Wnt sites is sufficient to drive expression of a reporter gene in a dorsal domain in transgenic Xenopus at the gastrula stage. We show that this pattern of expression of the transgene in gastrulae is not dependent on the T-box sites.

scholarly journals Regulation in the heart field of zebrafish

Development ◽  
1998 ◽  
Vol 125 (6) ◽  
pp. 1095-1101 ◽  
Author(s):  
G.N. Serbedzija ◽  
J.N. Chen ◽  
M.C. Fishman
Keyword(s):  
Cell Fate ◽  
Heart Development ◽  
Cell Labeling ◽  
Heart Cell ◽  
Lateral Plate Mesoderm ◽  
Lateral Plate ◽  
Cardiac Progenitors ◽  
Prechordal Plate ◽  
Early Expression ◽  
A Cell

In many vertebrates, removal of early embryonic heart precursors can be repaired, leaving the heart and embryo without visible deficit. One possibility is that this ‘regulation’ involves a cell fate switch whereby cells, perhaps in regions surrounding normal progenitors, are redirected to the heart cell fate. However, the lineage and spatial relationships between cells that are normal heart progenitors and those that can assume that role after injury are not known, nor are their molecular distinctions. We have adapted a laser-activated technique to label single or small patches of cells in the lateral plate mesoderm of the zebrafish and to track their subsequent lineage. We find that the heart precursor cells are clustered in a region adjacent to the prechordal plate, just anterior to the notochord tip. Complete unilateral ablation of all heart precursors with a laser does not disrupt heart development, if performed before the 18-somite stage. By combining extirpation of the heart precursors with cell labeling, we find that cells anterior to the normal cardiogenic compartments constitute the source of regulatory cells that compensate for the loss of the progenitors. One of the earliest embryonic markers of the premyocardial cells is the divergent homeodomain gene, Nkx2.5. Interestingly, normal cardiogenic progenitors derive from only the anterior half of the Nkx2.5-expressing region in the lateral plate mesoderm. The posterior half, adjacent to the notochord, does not include cardiac progenitors and the posterior Nkx2.5-expressing cells do not contribute to the heart, even after ablation of the normal cardiogenic region. The cells that can acquire a cardiac cell fate after injury to the normal progenitors also reside near the prechordal plate, but anterior to the Nkx2.5-expressing domain. Normally they give rise to head mesenchyme. They share with cardiac progenitors early expression of GATA 4. The location of the different elements of the cardiac field, and their response to injury, suggests that the prechordal plate supports and/or the notochord suppresses the cardiac fate.

scholarly journals FZD4 Marks Lateral Plate Mesoderm and Signals with NORRIN to Increase Cardiomyocyte Induction from Pluripotent Stem Cell-Derived Cardiac Progenitors

2018 ◽  
Vol 10 (1) ◽  
pp. 87-100 ◽  
Author(s):  
Charles Yoon ◽  
Hannah Song ◽  
Ting Yin ◽  
Damaris Bausch-Fluck ◽  
Andreas P. Frei ◽  
...  
Keyword(s):  
Stem Cell ◽  
Pluripotent Stem Cell ◽  
Lateral Plate Mesoderm ◽  
Lateral Plate ◽  
Cardiac Progenitors

scholarly journals Loss of Abdominal Muscle in Pitx2 Mutants Associated with Altered Axial Specification of Lateral Plate Mesoderm

PLoS ONE ◽  
2012 ◽  
Vol 7 (7) ◽  
pp. e42228 ◽  
Author(s):  
Diana Eng ◽  
Hsiao-Yen Ma ◽  
Jun Xu ◽  
Hung-Ping Shih ◽  
Michael K. Gross ◽  
...  
Keyword(s):  
Abdominal Muscle ◽  
Lateral Plate Mesoderm ◽  
Lateral Plate ◽  
Axial Specification

scholarly journals Charting cell migration dynamics during lateral plate mesoderm patterning in zebrafish using lightsheet microscopy

2017 ◽  
Vol 145 ◽  
pp. S79-S80
Author(s):  
Karin Dorien Prummel ◽  
Christopher Hess ◽  
Eline Brombacher ◽  
Anastasia Felker ◽  
Christian Mosimann
Keyword(s):  
Cell Migration ◽  
Lateral Plate Mesoderm ◽  
Lateral Plate ◽  
Migration Dynamics ◽  
Mesoderm Patterning

scholarly journals Antagonistic interactions in the zebrafish midline prior to the emergence of asymmetric gene expression are important for left–right patterning

2016 ◽  
Vol 371 (1710) ◽  
pp. 20150402 ◽  
Author(s):  
Rebecca D. Burdine ◽  
Daniel T. Grimes
Keyword(s):  
Gene Expression ◽  
Lateral Plate Mesoderm ◽  
Internal Organs ◽  
Lateral Plate ◽  
Left Right Asymmetry ◽  
Antagonistic Interactions

Left–right (L-R) asymmetry of the internal organs of vertebrates is presaged by domains of asymmetric gene expression in the lateral plate mesoderm (LPM) during somitogenesis. Ciliated L-R coordinators (LRCs) are critical for biasing the initiation of asymmetrically expressed genes, such as nodal and pitx2 , to the left LPM. Other midline structures, including the notochord and floorplate, are then required to maintain these asymmetries. Here we report an unexpected role for the zebrafish EGF-CFC gene one-eyed pinhead ( oep ) in the midline to promote pitx2 expression in the LPM. Late zygotic oep (LZ oep ) mutants have strongly reduced or absent pitx2 expression in the LPM, but this expression can be rescued to strong levels by restoring oep in midline structures only. Furthermore, removing midline structures from LZ oep embryos can rescue pitx2 expression in the LPM, suggesting the midline is a source of an LPM pitx2 repressor that is itself inhibited by oep . Reducing lefty1 activity in LZ oep embryos mimics removal of the midline, implicating lefty1 in the midline-derived repression. Together, this suggests a model where Oep in the midline functions to overcome a midline-derived repressor, involving lefty1 , to allow for the expression of left side-specific genes in the LPM. This article is part of the themed issue ‘Provocative questions in left–right asymmetry’.

scholarly journals Primary cilium polarity: morphogenetic consequences.

2018 ◽  
Author(s):  
Marco Regolini
Keyword(s):  
Primary Cilia ◽  
Break Symmetry ◽  
Otic Vesicle ◽  
Nodal Signaling ◽  
Lateral Plate Mesoderm ◽  
Cell Orientation ◽  
Lateral Plate ◽  
Situs Solitus ◽  
Left And Right ◽  
Breaking Symmetry

In zebrafish inner ear, hair cell orientation in anterior and posterior maculae of the embryonic otic vesicle is different (about 30-40 degrees): this is rather unusual in planar polarity mechanism of action, instead suggests that kinocilia may be rotationally polarized. In mice node, the innermost monociliated cells generate a left-ward fluid flow sensed by the immotile primary cilia of Left peri-nodal cells: the Nodal signaling pathway is then expressed asymmetrically, in the Left lateral plate mesoderm, breaking symmetry in visceral organs (situs solitus); however, Right peri-nodal cells also, if artificially excited by a right-ward flow, break symmetry and activate the Nodal cascade, though inverting visceral organ asymmetry (situs inversus); surprisingly, peri-nodal cells prove to be adept at distinguishing flow directionality. Recently, in the Kupffer vesicle (the zebrafish laterality organ), chiral primary cilia orientation has been described: primary cilia, in the left and right side, are symmetrically oriented, showing a mirror average divergence of about 15-20 degrees from the midline. This finding, taken together with the mirror behavior of mouse perinodal cells and zebrafish hair cells, champions the idea of primary cilia enantiomerism.

scholarly journals The occipital lateral plate mesoderm is a novel source for vertebrate neck musculature

Development ◽  
2010 ◽  
Vol 137 (17) ◽  
pp. 2961-2971 ◽  
Author(s):  
S. Theis ◽  
K. Patel ◽  
P. Valasek ◽  
A. Otto ◽  
Q. Pu ◽  
...  
Keyword(s):  
Lateral Plate Mesoderm ◽  
Lateral Plate ◽  
Neck Musculature
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