Foxg specifies sensory neurons in the anterior neural plate border of the ascidian embryo

Abstract Foxg constitutes a regulatory loop with Fgf8 and plays an important role in the development of anterior placodes and the telencephalon in vertebrate embryos. Ascidians, which belong to Tunicata, the sister group of vertebrates, develop a primitive placode-like structure at the anterior boundary of the neural plate, but lack a clear counterpart of the telencephalon. In this animal, Foxg is expressed in larval palps, which are adhesive organs with sensory neurons. Here, we show that Foxg begins to be expressed in two separate rows of cells within the neural plate boundary region under the control of the MAPK pathway to pattern this region. However, Foxg is not expressed in the brain, and we find no evidence that knockdown of Foxg affects brain formation. Our data suggest that recruitment of Fgf to the downstream of Foxg might have been a critical evolutionary event for the telencephalon in the vertebrate lineage.

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Zebrafish narrowminded suggests a genetic link between formation of neural crest and primary sensory neurons

Development ◽

10.1242/dev.126.18.3969 ◽

1999 ◽

Vol 126 (18) ◽

pp. 3969-3979 ◽

Cited By ~ 3

Author(s):

K.B. Artinger ◽

A.B. Chitnis ◽

M. Mercola ◽

W. Driever

Keyword(s):

Neural Crest ◽

Sensory Neurons ◽

Cell Formation ◽

Plate Boundary ◽

Neural Crest Cell ◽

Neural Crest Cells ◽

Neural Plate ◽

Crest Cell

In the developing vertebrate nervous system, both neural crest and sensory neurons form at the boundary between non-neural ectoderm and the neural plate. From an in situ hybridization based expression analysis screen, we have identified a novel zebrafish mutation, narrowminded (nrd), which reduces the number of early neural crest cells and eliminates Rohon-Beard (RB) sensory neurons. Mosaic analysis has shown that the mutation acts cell autonomously suggesting that nrd is involved in either the reception or interpretation of signals at the lateral neural plate boundary. Characterization of the mutant phenotype indicates that nrd is required for a primary wave of neural crest cell formation during which progenitors generate both RB sensory neurons and neural crest cells. Moreover, the early deficit in neural crest cells in nrd homozygotes is compensated later in development. Thus, we propose that a later wave can compensate for the loss of early neural crest cells but, interestingly, not the RB sensory neurons. We discuss the implications of these findings for the possibility that RB sensory neurons and neural crest cells share a common evolutionary origin.

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Vp/Vs tomography in the southern California plate boundary region using body and surface wave traveltime data

Geophysical Journal International ◽

10.1093/gji/ggy458 ◽

2018 ◽

Vol 216 (1) ◽

pp. 609-620 ◽

Cited By ~ 4

Author(s):

Hongjian Fang ◽

Huajian Yao ◽

Haijiang Zhang ◽

Clifford Thurber ◽

Yehuda Ben-Zion ◽

...

Keyword(s):

Surface Wave ◽

Southern California ◽

Plate Boundary ◽

Boundary Region

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Semi-supervised Data-driven Surface Wave Tomography using Wasserstein Cycle-consistent GAN: Application on Southern California Plate Boundary Region

10.1002/essoar.10505231.1 ◽

2020 ◽

Author(s):

Ao Cai ◽

Hongrui Qiu ◽

Fenglin Niu

Keyword(s):

Surface Wave ◽

Southern California ◽

Plate Boundary ◽

Boundary Region ◽

Data Driven ◽

Surface Wave Tomography ◽

Wave Tomography

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Semi-supervised Surface Wave Tomography with Wasserstein Cycle-consistent GAN: Method and Application on Southern California Plate Boundary Region

10.1002/essoar.10505230.1 ◽

2020 ◽

Author(s):

Ao Cai ◽

Hongrui Qiu ◽

Fenglin Niu

Keyword(s):

Surface Wave ◽

Southern California ◽

Plate Boundary ◽

Boundary Region ◽

Surface Wave Tomography ◽

Wave Tomography

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Ectodermal patterning in the avian embryo: epidermis versus neural plate

Development ◽

10.1242/dev.126.1.63 ◽

1999 ◽

Vol 126 (1) ◽

pp. 63-73 ◽

Cited By ~ 8

Author(s):

E. Pera ◽

S. Stein ◽

M. Kessel

Keyword(s):

Chick Embryo ◽

Neural Crest ◽

Plate Boundary ◽

Homeobox Gene ◽

Primitive Streak ◽

Neural Plate ◽

Avian Embryo ◽

Neural Fate ◽

Early Stages ◽

Two Factors

Ectodermal patterning of the chick embryo begins in the uterus and continues during gastrulation, when cells with a neural fate become restricted to the neural plate around the primitive streak, and cells fated to become the epidermis to the periphery. The prospective epidermis at early stages is characterized by the expression of the homeobox gene DLX5, which remains an epidermal marker during gastrulation and neurulation. Later, some DLX5-expressing cells become internalized into the ventral forebrain and the neural crest at the hindbrain level. We studied the mechanism of ectodermal patterning by transplantation of Hensen's nodes and prechordal plates. The DLX5 marker indicates that not only a neural plate, but also a surrounding epidermis is induced in such operations. Similar effects can be obtained with neural plate grafts. These experiments demonstrate that the induction of a DLX5-positive epidermis is triggered by the midline, and the effect is transferred via the neural plate to the periphery. By repeated extirpations of the endoderm we suppressed the formation of an endoderm/mesoderm layer under the epiblast. This led to the generation of epidermis, and to the inhibition of neuroepithelium in the naked ectoderm. This suggests a signal necessary for neural, but inhibitory for epidermal development, normally coming from the lower layers. Finally, we demonstrate that BMP4, as well as BMP2, is capable of inducing epidermal fate by distorting the epidermis-neural plate boundary. This, however, does not happen independently within the neural plate or outside the normal DLX5 domain. In the area opaca, the co-transplantation of a BMP4 bead with a node graft leads to the induction of DLX5, thus indicating the cooperation of two factors. We conclude that ectodermal patterning is achieved by signalling both from the midline and from the periphery, within the upper but also from the lower layers.

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