Germ layers

AccessScience ◽  
2015 ◽  
Keyword(s):  
Germ Layers

Concurrent Thoracic Spinal Intradural Extramedullary Epidermoid and Neurenteric Cyst in a Spinal Dysraphism Child

2021 ◽  
pp. 1-7
Author(s):  
Rajeev Sharma ◽  
Swati Mahajan ◽  
Minakshi Bhardwaj ◽  
Laxmi Naraian Gupta ◽  
Deepak Gupta
Keyword(s):  
Surgical Planning ◽  
English Literature ◽  
Spinal Dysraphism ◽  
Neurenteric Cyst ◽  
Germ Layers ◽  
Case Presentation ◽  
Spinal Lesions ◽  
Congenital Origin ◽  
Thoracic Spinal ◽  
Intradural Extramedullary

<b><i>Introduction:</i></b> Intraspinal epidermoid cysts are congenital or acquired in origin; whereas intraspinal neurenteric cysts (NECs) are of congenital origin. Their individual association with spinal dysraphism and vertebral segmentation anomalies is very well known. <b><i>Case presentation:</i></b> We hereby report a case of concurrent intradural extramedullary epidermoid and NEC at adjacent vertebral levels in a spinal dysraphism child, not reported in English Literature till now. <b><i>Conclusion:</i></b> Multiple spinal lesions related to any/all of the 3 germ layers can coexist at same or adjacent vertebral levels in the same patient and surgical planning shown to be done accordingly.

scholarly journals Rhesus iPSC Safe Harbor Gene-Editing Platform for Stable Expression of Transgenes in Differentiated Cells of All Germ Layers

2017 ◽  
Vol 25 (1) ◽  
pp. 44-53 ◽  
Author(s):  
So Gun Hong ◽  
Ravi Chandra Yada ◽  
Kyujoo Choi ◽  
Arnaud Carpentier ◽  
T. Jake Liang ◽  
...  
Keyword(s):  
Gene Editing ◽  
Stable Expression ◽  
Safe Harbor ◽  
Germ Layers ◽  
Differentiated Cells

scholarly journals Mouse Androgenetic Embryonic Stem Cells Differentiated to Multiple Cell Lineages in Three Embryonic Germ Layers In Vitro

2009 ◽  
Vol 55 (3) ◽  
pp. 283-292 ◽  
Author(s):  
Takeshi TERAMURA ◽  
Yuta ONODERA ◽  
Hideki MURAKAMI ◽  
Syunsuke ITO ◽  
Toshihiro MIHARA ◽  
...  
Keyword(s):  
Stem Cells ◽  
Embryonic Stem Cells ◽  
Embryonic Stem ◽  
Germ Layers ◽  
Cell Lineages ◽  
Multiple Cell

Interacting functions of snail, twist and huckebein during the early development of germ layers in Drosophila

Development ◽  
1994 ◽  
Vol 120 (5) ◽  
pp. 1137-1150 ◽  
Author(s):  
R. Reuter ◽  
M. Leptin
Keyword(s):  
Transcription Factors ◽  
Digestive Tract ◽  
Early Development ◽  
Target Genes ◽  
Anterior Part ◽  
Posterior Part ◽  
Germ Layers ◽  
Mesoderm Development ◽  
Ventral Furrow

Two zygotic genes, snail (sna) and twist (twi), are required for mesoderm development, which begins with the formation of the ventral furrow. Both twi and sna are expressed ventrally in the blastoderm, encode transcription factors and promote the invagination of the ventral furrow by activating or repressing appropriate target genes. However, sna and twi alone do not define the position of the ventral furrow, since they are also expressed in ventral cells that do not invaginate. We show that huckebein (hkb) sets the anterior and the posterior borders of the ventral furrow, but acts by different modes of regulation. In the posterior part of the blastoderm, hkb represses the expression of sna in the endodermal primordium (which we suggest to be adjacent to the mesodermal primordium). In the anterior part, hkb antagonizes the activation of target genes by twi and sna. Here, bicoid permits the co-expression of hkb, sna and twi, which are all required for the development of the anterior digestive tract. We suggest that mesodermal fate is determined where sna and twi but not hkb are expressed. Anteriorly hkb together with sna determines endodermal fate, and hkb together with sna and twi are required for foregut development.

Inductive patterning of the embryonic brain in Drosophila

Development ◽  
2002 ◽  
Vol 129 (9) ◽  
pp. 2121-2128
Author(s):  
Damon T. Page
Keyword(s):  
Brain Development ◽  
Common Ancestor ◽  
Last Common Ancestor ◽  
Embryonic Brain ◽  
Germ Layers ◽  
Brain Anomaly ◽  
Prechordal Plate ◽  
Foregut Endoderm ◽  
The Brain ◽  
Brain Patterning

In vertebrates (deuterostomes), brain patterning depends on signals from adjacent tissues. For example, holoprosencephaly, the most common brain anomaly in humans, results from defects in signaling between the embryonic prechordal plate (consisting of the dorsal foregut endoderm and mesoderm) and the brain. I have examined whether a similar mechanism of brain development occurs in the protostome Drosophila, and find that the foregut and mesoderm act to pattern the fly embryonic brain. When the foregut and mesoderm of Drosophila are ablated, brain patterning is disrupted. The loss of Hedgehog expressed in the foregut appears to mediate this effect, as it does in vertebrates. One mechanism whereby these defects occur is a disruption of normal apoptosis in the brain. These data argue that the last common ancestor of protostomes and deuterostomes had a prototype of the brains present in modern animals, and also suggest that the foregut and mesoderm contributed to the patterning of this ‘proto-brain’. They also argue that the foreguts of protostomes and deuterostomes, which have traditionally been assigned to different germ layers, are actually homologous.

Investigation on the origin of the definitive endoderm in the rat embryo

Development ◽  
1974 ◽  
Vol 32 (2) ◽  
pp. 445-459
Author(s):  
B. Levak-Švajger ◽  
A. Švajger
Keyword(s):  
Primitive Streak ◽  
Definitive Endoderm ◽  
Rat Embryo ◽  
Chick Blastoderm ◽  
Germ Layers ◽  
Kidney Capsule ◽  
Rat Embryos ◽  
Endodermal Cells ◽  
Derivatives Of

Single germ layers (or combinations of two of them) were isolated from the primitive streak and the head-fold stage rat embryos and grown for 15 days under the kidney capsule of syngeneic adult animals. The resulting teratomas were examined histologically for the presence of mature tissues, with special emphasis on derivatives of the primitive gut. Ectoderm isolated together with the initial mesodermal wings at the primitive streak stage gave rise to tissue derivatives of all three definitive germ layers. Derivatives of the primitive gut were regularly present in these grafts. At the head-fold stage, isolated ectoderm (including the region of the primitive streak) differentiated into ectodermal and mesodermal derivatives only. Endoderm isolated at the primitive streak stage did not develop when grafted and was always completely resorbed. At the head-fold stage, however, definitive endoderm differentiated into derivatives of the primitive gut if grafted together with adjacent mesoderm. These findings indirectly suggest the migration of prospective endodermal cells from the primitive ectoderm, and therefore a general analogy with the course of events during gastrulation in the chick blastoderm.

scholarly journals Rac1 is required for the formation of three germ layers during gastrulation

Oncogene ◽  
1998 ◽  
Vol 17 (26) ◽  
pp. 3427-3433 ◽  
Author(s):  
Kazuhiro Sugihara ◽  
Norio Nakatsuji ◽  
Kenji Nakamura ◽  
Kazuki Nakao ◽  
Ryuju Hashimoto ◽  
...  
Keyword(s):  
Germ Layers

scholarly journals Mapping single-cell atlases throughout Metazoa unravels cell type evolution

eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Alexander J Tarashansky ◽  
Jacob M Musser ◽  
Margarita Khariton ◽  
Pengyang Li ◽  
Detlev Arendt ◽  
...  
Keyword(s):  
Stem Cell ◽  
Single Cell ◽  
Cell Types ◽  
The Self ◽  
Cell Type ◽  
Germ Layers ◽  
Animal Evolution ◽  
Self Assembling ◽  
Animal Phyla ◽  
Cell Data

Comparing single-cell transcriptomic atlases from diverse organisms can elucidate the origins of cellular diversity and assist the annotation of new cell atlases. Yet, comparison between distant relatives is hindered by complex gene histories and diversifications in expression programs. Previously, we introduced the self-assembling manifold (SAM) algorithm to robustly reconstruct manifolds from single-cell data (Tarashansky et al., 2019). Here, we build on SAM to map cell atlas manifolds across species. This new method, SAMap, identifies homologous cell types with shared expression programs across distant species within phyla, even in complex examples where homologous tissues emerge from distinct germ layers. SAMap also finds many genes with more similar expression to their paralogs than their orthologs, suggesting paralog substitution may be more common in evolution than previously appreciated. Lastly, comparing species across animal phyla, spanning mouse to sponge, reveals ancient contractile and stem cell families, which may have arisen early in animal evolution.

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