Development and characterization of commissural interneurones in the spinal cord of Xenopus laevis embryos revealed by antibodies to glycine

Development ◽  
1988 ◽  
Vol 103 (3) ◽  
pp. 447-461 ◽  
Author(s):  
A. Roberts ◽  
N. Dale ◽  
O.P. Ottersen ◽  
J. Storm-Mathisen
Keyword(s):  
Spinal Cord ◽  
Xenopus Laevis ◽  
Neural Tube ◽  
Detailed Comparison ◽  
Neural Tube Closure ◽  
Spinal Interneurones ◽  
Inhibitory Function ◽  
Process Formation ◽  
Xenopus Laevis Embryos

By using an antibody to glutaraldehyde fixation products of glycine we have been able to observe the development of a defined population of spinal interneurones in the CNS of Xenopus laevis embryos. The first glycine immunoreactive (GLY) somata appeared at stage 22 in the caudal hindbrain within a few hours of neural tube closure. The population then increased by extending caudally into the spinal cord and by infill. It was followed up to the time of hatching, stage 37/38. By observing GLY cells at early stages in their differentiation, the normal sequence of cell process formation was deduced. A ventral axon is formed, extends dendrites laterally into the marginal zone and forms a commissure by growing through the ventral ependymal cell floor of the neural tube. On the opposite side, growth cones turn longitudinally and TEM observations show that they make en-passant synaptic contacts. All GLY cells have decussating axons and some grow secondary axons on the same side as the soma. To establish the identity of GLY cells, a detailed comparison was made with commissural and dorsolateral commissural interneurones defined by retrograde and intracellular HRP staining. The GLY cells are identified with the commissural interneurones which are known to serve a glycinergic reciprocal inhibitory function. By showing that these interneurones have a clearly defined group identity and programme of development, this study opens the way to further experiments on factors controlling spinal cord pathway determination.

Hoxd10 induction and regionalization in the developing lumbosacral spinal cord

Development ◽  
2001 ◽  
Vol 128 (12) ◽  
pp. 2255-2268 ◽  
Author(s):  
Cynthia Lance-Jones ◽  
Natalia Omelchenko ◽  
Anya Bailis ◽  
Stephen Lynch ◽  
Kamal Sharma
Keyword(s):  
Spinal Cord ◽  
Neural Tube ◽  
Neural Tube Closure ◽  
Paraxial Mesoderm ◽  
Lumbosacral Region ◽  
Environmental Signals ◽  
Lumbosacral Spinal Cord ◽  
Column Formation ◽  
Lim Proteins ◽  
High Level

We have used Hoxd10 expression as a primary marker of the lumbosacral region to examine the early programming of regional characteristics within the posterior spinal cord of the chick embryo. Hoxd10 is uniquely expressed at a high level in the lumbosacral cord, from the earliest stages of motor column formation through stages of motoneuron axon outgrowth. To define the time period when this gene pattern is determined, we assessed Hoxd10 expression after transposition of lumbosacral and thoracic segments at early neural tube stages. We present evidence that there is an early prepattern for Hoxd10 expression in the lumbosacral neural tube; a prepattern that is established at or before stages of neural tube closure. Cells within more posterior lumbosacral segments have a greater ability to develop high level Hoxd10 expression than the most anterior lumbosacral segments or thoracic segments. During subsequent neural tube stages, this prepattern is amplified and stabilized by environmental signals such that all lumbosacral segments acquire the ability to develop high levels of Hoxd10, independent of their axial environment. Results from experiments in which posterior neural segments and/or paraxial mesoderm segments were placed at different axial levels suggest that signals setting Hoxd10 expression form a decreasing posterior-to-anterior gradient. Our experiments do not, however, implicate adjacent paraxial mesoderm as the only source of graded signals. We suggest, instead, that signals from more posterior embryonic regions influence Hoxd10 expression after the early establishment of a regional prepattern. Concurrent analyses of patterns of LIM proteins and motor column organization after experimental surgeries suggest that the programming of these characteristics follows similar rules.

The control of rostrocaudal pattern in the developing spinal cord: specification of motor neuron subtype identity is initiated by signals from paraxial mesoderm

Development ◽  
1998 ◽  
Vol 125 (6) ◽  
pp. 969-982 ◽  
Author(s):  
M. Ensini ◽  
T.N. Tsuchida ◽  
H.G. Belting ◽  
T.M. Jessell
Keyword(s):  
Spinal Cord ◽  
Motor Neuron ◽  
Motor Neurons ◽  
Neural Tube ◽  
Motor Behavior ◽  
Neural Tube Closure ◽  
Paraxial Mesoderm ◽  
Homeodomain Protein ◽  
Mesodermal Cell ◽  
Developing Spinal Cord

The generation of distinct classes of motor neurons is an early step in the control of vertebrate motor behavior. To study the interactions that control the generation of motor neuron subclasses in the developing avian spinal cord we performed in vivo grafting studies in which either the neural tube or flanking mesoderm were displaced between thoracic and brachial levels. The positional identity of neural tube cells and motor neuron subtype identity was assessed by Hox and LIM homeodomain protein expression. Our results show that the rostrocaudal identity of neural cells is plastic at the time of neural tube closure and is sensitive to positionally restricted signals from the paraxial mesoderm. Such paraxial mesodermal signals appear to control the rostrocaudal identity of neural tube cells and the columnar subtype identity of motor neurons. These results suggest that the generation of motor neuron subtypes in the developing spinal cord involves the integration of distinct rostrocaudal and dorsoventral patterning signals that derive, respectively, from paraxial and axial mesodermal cell groups.

scholarly journals Differentiation and localization of interneurons in the developing spinal cord depends on DOT1L expression

2020 ◽  
Author(s):  
Angelica Gray de Cristoforis ◽  
Francesco Ferrari ◽  
Frédéric Clotman ◽  
Tanja Vogel
Keyword(s):  
Spinal Cord ◽  
Neural Tube ◽  
Transcriptional Activation ◽  
Neural Tube Closure ◽  
Epigenetic Factors ◽  
Late Developmental Stage ◽  
Neural Tube Closure Defect ◽  
H3k79 Methylation ◽  
Tube Closure ◽  
Developing Spinal Cord

Abstract Genetic and epigenetic factors contribute to the development of the spinal cord. Failure in correct exertion of the developmental programs, including neurulation, neural tube closure and neurogenesis of the diverse spinal cord neuronal subtypes results in clinical phenotypes with variable severity. The histone methyltransferase Disruptor of Telomeric 1 Like (DOT1L), which mediates histone H3 lysine 79 (H3K79) methylation, is fundamental for proper development of the cerebral cortex and cerebellum, and here we report on its essential role for development of the spinal cord. Conditional inactivation of DOT1L using Wnt1-cre as driver in the developing murine spinal cord did not result in neural tube closure defect (NTCD). Transcriptome analysis revealed that DOT1L deficiency favored differentiation over progenitor proliferation. Dot1l -cKO mainly decreased the numbers of dI1 interneurons expressing Lhx2 . Loss of DOT1L affected localization but not generation of dI2, dI3, and dI5 interneurons. The resulting derailed interneuron patterns might be responsible for increased cell death that occurred at the late developmental stage E18.5. Together our data indicate that DOT1L is essential for subtype- specific neurogenesis, migration and localization of interneurons in the developing spinal cord, in part by regulating transcriptional activation of Lhx2 .

scholarly journals Generation and characterization of a novel neural crest marker allele, Inka1-LacZ, reveals a role for Inka1 in mouse neural tube closure

2010 ◽  
Vol 239 (4) ◽  
pp. 1188-1196 ◽  
Author(s):  
Bethany S. Reid ◽  
Thomas D. Sargent ◽  
Trevor Williams
Keyword(s):  
Neural Crest ◽  
Neural Tube ◽  
Neural Tube Closure ◽  
Marker Allele ◽  
Tube Closure

Characterization of Modified Antisense Oligonucleotides in Xenopus laevis Embryos

2006 ◽  
Vol 16 (1) ◽  
pp. 26-42 ◽  
Author(s):  
Kim A. Lennox ◽  
Jaime L. Sabel ◽  
Maegan J. Johnson ◽  
Bernardo G. Moreira ◽  
Cherisa A. Fletcher ◽  
...  
Keyword(s):  
Xenopus Laevis ◽  
Antisense Oligonucleotides ◽  
Xenopus Laevis Embryos

Open brain, a new mouse mutant with severe neural tube defects, shows altered gene expression patterns in the developing spinal cord

Development ◽  
1994 ◽  
Vol 120 (11) ◽  
pp. 3119-3130 ◽  
Author(s):  
T. Gunther ◽  
M. Struwe ◽  
A. Aguzzi ◽  
K. Schughart
Keyword(s):  
Gene Expression ◽  
Spinal Cord ◽  
Dorsal Root Ganglia ◽  
Neural Tube ◽  
Dorsal Root ◽  
Expression Patterns ◽  
Axial Skeleton ◽  
Neural Tube Closure ◽  
Primary Defect ◽  
Developing Spinal Cord

We describe a new mouse mutation, designated open brain (opb), which results in severe defects in the developing neural tube. Homozygous opb embryos exhibited an exencephalic malformation involving the forebrain, midbrain and hindbrain regions. The primary defect of the exencephaly could be traced back to a failure to initiate neural tube closure at the midbrain-forebrain boundary. Severe malformations in the spinal cord and dorsal root ganglia were observed in the thoracic region. The spinal cord of opb mutant embryos exhibited an abnormal circular to oval shape and showed defects in both ventral and dorsal regions. In severely affected spinal cord regions, a dorsalmost region of cells negative for Wnt-3a, Msx-2, Pax-3 and Pax-6 gene expression was detected and dorsal expression of Pax-6 was increased. In ventral regions, the area of Shh and HNF-3 beta expression was enlarged and the future motor neuron horns appeared to be reduced in size. These observations indicate that opb embryos exhibit defects in the specification of cells along the dorsoventral axis of the developing spinal cord. Although small dorsal root ganglia were formed in opb mutants, their metameric organization was lost. In addition, defects in eye development and malformations in the axial skeleton and developing limbs were observed. The implications of these findings are discussed in the context of dorsoventral patterning of the developing neural tube and compared with known mouse mutants exhibiting similar defects.

Neural Fold Fusion in Xenopus Laevis Embryos

1974 ◽  
Vol 32 ◽  
pp. 282-283
Author(s):  
Linda L. Mak
Keyword(s):  
Electron Microscopy ◽  
Xenopus Laevis ◽  
Neural Tube ◽  
Morphological Study ◽  
Xenopus Laevis Embryos

A morphological study of neural fold fusion in neurulae of the African Clawed Toad Xenopus laevis was undertaken. Segments of neural folds were dissected from embryos at Nieuwkoop and Faber stages 18 (neural groove), 19 (neural fold fusion) and 20 (neural tube) and fixed for electron microscopy.Cells from specimens in the prefusion stage exhibited much vesicular activity, especially those lining the neural groove. In certain instances the vesicles were open, extruding organelles and cytoplasm into the neural groove. The membranous projections of these opened vesicles protruded into the extraembryonic space. Vesicles (v, Fig. 1) were arranged in rows below the surfaces of cells lying along the neural groove. Some vesicles appeared to coalesce to form larger ones.

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