The Arrangement of Early Inductive Signals in Relation to Gastrulation; Results from Frog and Chick

Gastrulation ◽  
1991 ◽  
pp. 79-99 ◽  
Author(s):  
Jonathan Cooke
Keyword(s):  
Inductive Signals

Integration of floral inductive signals in Arabidopsis

Nature ◽  
2000 ◽  
Vol 404 (6780) ◽  
pp. 889-892 ◽  
Author(s):  
Miguel A. Blázquez ◽  
Detlef Weigel
Keyword(s):  
Inductive Signals

BMPs are necessary for stomach gland formation in the chicken embryo: a study using virally induced BMP-2 and Noggin expression

Development ◽  
2000 ◽  
Vol 127 (5) ◽  
pp. 981-988 ◽  
Author(s):  
T. Narita ◽  
K. Saitoh ◽  
T. Kameda ◽  
A. Kuroiwa ◽  
M. Mizutani ◽  
...  
Keyword(s):  
Bone Morphogenetic Proteins ◽  
Chicken Embryo ◽  
Normal Development ◽  
Expression Patterns ◽  
Ectopic Expression ◽  
Complete Inhibition ◽  
Glandular Stomach ◽  
Digestive Organs ◽  
Chicken Proventriculus ◽  
Inductive Signals

Epithelial-mesenchymal interactions are necessary for the normal development of various digestive organs. In chicken proventriculus (glandular stomach), morphogenesis and differentiation of the epithelium depend upon the inductive signals coming from underlying mesenchyme. However, the nature of such signals is still unclear despite extensive analyses carried out using experimental tissue recombinations. In this study we have examined the possible involvement of bone morphogenetic proteins (BMPs) in the formation of stomach glands in the chicken embryo. Analysis of the expression patterns of BMP-2, −4 and −7 showed that these BMPs were present in the proventricular mesenchyme prior to the initiation of the proventricular gland formation. BMP-2 expression, in particular, was restricted to the proventriculus among anterior digestive organs. Virus-mediated BMP-2 overexpression resulted in an increase in the number of glands formed. Moreover, ectopic expression of Noggin, which antagonizes the effect of BMPs, in the proventricular mesenchyme or epithelium, led to the complete inhibition of gland formation, indicating that BMP signals are necessary for the proventricular gland formation. These findings suggest that BMPs are of prime importance as mesenchymal signals for inducing proventricular glands.

Stage-specific inductive signals in the Drosophila neuroectoderm control the temporal sequence of neuroblast specification

Development ◽  
2001 ◽  
Vol 128 (17) ◽  
pp. 3243-3251 ◽  
Author(s):  
Christian Berger ◽  
Joachim Urban ◽  
Gerhard M. Technau
Keyword(s):  
Progenitor Cells ◽  
Neural Progenitor Cells ◽  
Time Window ◽  
Neural Progenitor ◽  
Temporal Sequence ◽  
Drosophila Embryo ◽  
Transplantation Experiments ◽  
Reduced Time ◽  
Inductive Signals

One of the initial steps of neurogenesis in the Drosophila embryo is the delamination of a stereotype set of neural progenitor cells (neuroblasts) from the neuroectoderm. The time window of neuroblast segregation has been divided into five successive waves (S1-S5) in which subsets of neuroblasts with specific identities are formed. To test when identity specification of the various neuroblasts takes place and whether extrinsic signals are involved, we have performed heterochronic transplantation experiments. Single neuroectodermal cells from stage 10 donor embryos (after S2) were transplanted into the neuroectoderm of host embryos at stage 7 (before S1) and vice versa. The fate of these cells was uncovered by their lineages at stage 16/17. Transplanted cells adjusted their fate to the new temporal situation. Late neuroectodermal cells were able to take over the fate of early (S1/S2) neuroblasts. The early neuroectodermal cells preferentially generated late (S4/S5) neuroblasts, despite their reduced time of exposure to the neuroectoderm. Furthermore, neuroblast fates are independent from divisions of neuroectodermal progenitor cells. We conclude from these experiments that neuroblast specification occurs sequentially under the control of non-cell-autonomous and stage-specific inductive signals that act in the neuroectoderm.

scholarly journals LRP2 Is an Auxiliary SHH Receptor Required to Condition the Forebrain Ventral Midline for Inductive Signals

2012 ◽  
Vol 22 (2) ◽  
pp. 268-278 ◽  
Author(s):  
Annabel Christ ◽  
Anna Christa ◽  
Esther Kur ◽  
Oleg Lioubinski ◽  
Sebastian Bachmann ◽  
...  
Keyword(s):  
Ventral Midline ◽  
Inductive Signals

scholarly journals delayed flowering1 Encodes a Basic Leucine Zipper Protein That Mediates Floral Inductive Signals at the Shoot Apex in Maize

2006 ◽  
Vol 142 (4) ◽  
pp. 1523-1536 ◽  
Author(s):  
Michael G. Muszynski ◽  
Thao Dam ◽  
Bailin Li ◽  
David M. Shirbroun ◽  
Zhenglin Hou ◽  
...  
Keyword(s):  
Shoot Apex ◽  
Leucine Zipper ◽  
Basic Leucine Zipper ◽  
Leucine Zipper Protein ◽  
Inductive Signals

scholarly journals Convergent Inductive Signals Specify Midbrain, Hindbrain, and Spinal Cord Identity in Gastrula Stage Chick Embryos

Neuron ◽  
1999 ◽  
Vol 23 (4) ◽  
pp. 689-702 ◽  
Author(s):  
Jonas Muhr ◽  
Enrique Graziano ◽  
Sara Wilson ◽  
Thomas M Jessell ◽  
Thomas Edlund
Keyword(s):  
Spinal Cord ◽  
Chick Embryos ◽  
Gastrula Stage ◽  
Inductive Signals

scholarly journals XASH-3, a novel Xenopus achaete-scute homolog, provides an early marker of planar neural induction and position along the mediolateral axis of the neural plate

Development ◽  
1993 ◽  
Vol 119 (1) ◽  
pp. 221-232 ◽  
Author(s):  
K. Zimmerman ◽  
J. Shih ◽  
J. Bars ◽  
A. Collazo ◽  
D.J. Anderson
Keyword(s):  
Spinal Cord ◽  
Neural Induction ◽  
Neural Plate ◽  
Early Event ◽  
Boundary Zone ◽  
Anteroposterior Axis ◽  
Early Marker ◽  
Positional Identity ◽  
Inductive Signals

We have isolated a novel Xenopus homolog of the Drosophila achaete-scute genes, called XASH-3. XASH-3 expression is neural specific and is detected as early as stage 11 1/2, making it one of the earliest markers of neural induction so far described. Moreover, XASH-3 expression within the neural plate is regionally restricted. Transverse bands of XASH-3 mRNA mark discrete positions along the anteroposterior axis, while longitudinal bands mark a discrete position along the mediolateral axis. This latter site of XASH-3 expression appears to demarcate the prospective sulcus limitans, a boundary zone that later separates the functionally distinct dorsal (alar) and ventral (basal) regions of the spinal cord. In sandwich explants lacking any underlying mesoderm, XASH-3 is expressed in longitudinal stripes located lateral to the midline. This provides the first indication that planar or midline-derived inductive signals are sufficient to establish at least some aspects of positional identity along the mediolateral axis of the neural plate. By contrast, the transverse stripes of XASH-3 expression are not detected, suggesting that this aspect of anteroposterior neural pattern is lost or delayed in the absence of vertically passed signals. The restricted mediolateral expression of XASH-3 suggests that mediolateral patterning of the neural plate is an early event, and that this regionalization can be achieved in the absence of inducing signals derived from underlying mesoderm.

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