Cngsc, a homologue of goosecoid, participates in the patterning of the head, and is expressed in the organizer region of Hydra

Development ◽  
1999 ◽  
Vol 126 (23) ◽  
pp. 5245-5254 ◽  
Author(s):  
M. Broun ◽  
S. Sokol ◽  
H.R. Bode
Keyword(s):  
Sensory Neurons ◽  
Organizer Region ◽  
Ventral Side ◽  
Evolutionary Conservation ◽  
The Body ◽  
Secondary Axis ◽  
Head Formation ◽  
Per Se ◽  
Endodermal Cells ◽  
Body Column

We have isolated Cngsc, a hydra homologue of goosecoid gene. The homeodomain of Cngsc is identical to the vertebrate (65-72%) and Drosophila (70%) orthologues. When injected into the ventral side of an early Xenopus embryo, Cngsc induces a partial secondary axis. During head formation, Cngsc expression appears prior to, and directly above, the zone where the tentacles will emerge, but is not observed nearby when the single apical tentacle is formed. This observation indicates that the expression of the gene is not necessary for the formation of a tentacle per se. Rather, it may be involved in defining the border between the hypostome and the tentacle zone. When Cngsc(+) tip of an early bud is grafted into the body column, it induces a secondary axis, while the adjacent Cngsc(−) region has much weaker inductive capacities. Thus, Cngsc is expressed in a tissue that acts as an organizer. Cngsc is also expressed in the sensory neurons of the tip of the hypostome and in the epithelial endodermal cells of the upper part of the body column. The plausible roles of Cngsc in organizer function, head formation and anterior neuron differentiation are similar to roles goosecoid plays in vertebrates and Drosophila. It suggests widespread evolutionary conservation of the function of the gene.

Characterization of the head organizer in hydra

Development ◽  
2002 ◽  
Vol 129 (4) ◽  
pp. 875-884 ◽  
Author(s):  
Mariya Broun ◽  
Hans R. Bode
Keyword(s):  
Organizer Region ◽  
Apical Part ◽  
The Body ◽  
Central Process ◽  
Axial Patterning ◽  
Secondary Axis ◽  
Head Formation ◽  
Body Column ◽  
Self Organizing

A central process in the maintenance of axial patterning in the adult hydra is the head activation gradient, i.e. the potential to form a secondary axis, which is maximal in the head and is graded down the body column. Earlier evidence suggested that this gradient was based on a single parameter. Using transplantation experiments, we provide evidence that the hypostome, the apical part of the head, has the characteristics of an organizer in that it has the capacity to induce host tissue to form most of the second axis. By contrast, tissue of the body column has a self-organizing capacity, but not an inductive capacity. That the inductive capacity is confined to the hypostome is supported by experiments involving a hypostome-contact graft. The hypostome, but not the body column, transmits a signal(s) leading to the formation of a second axis. In addition, variations of the transplantation grafts and hypostome-contact grafts provide evidence for several characteristics of the organizer. The inductive capacity of the head and the self-organizing capacity of the body column are based on different pathways. Head inhibition, yya signal produced in the head and transmitted to the body column to prevent head formation, represses the effect of the inducing signal by interfering with formation of the hypostome/organizer. These results indicate that the organizer characteristics of the hypostome of an adult hydra are similar to those of the organizer region of vertebrate embryos. They also indicate that the Gierer-Meinhardt model provides a reasonable framework for the mechanisms that underlie the organizer and its activities. In addition, the results suggest that a region of an embryo or adult with the characteristics of an organizer arose early in metazoan evolution.

scholarly journals A Wnt-specific astacin proteinase controls head formation in Hydra

2020 ◽  
Author(s):  
Berenice Ziegler ◽  
Irene Yiallouros ◽  
Benjamin Trageser ◽  
Sumit Kumar ◽  
Moritz Mercker ◽  
...  
Keyword(s):  
The Body ◽  
Regulatory Function ◽  
Beta Catenin ◽  
Processing Factor ◽  
Primary Body ◽  
Head Formation ◽  
Signaling Center ◽  
Sirna Knockdown ◽  
Body Column ◽  
Activator Inhibitor

AbstractThe Hydra head organizer acts as a signaling center that initiates and maintains the primary body axis in steady state polyps and during budding or regeneration. Wnt/beta-Catenin signaling functions as a primary cue controlling this process, but how Wnt ligand activity is locally restricted at the protein level is poorly understood.Here we report the identification of an astacin family proteinase as a Wnt processing factor. Hydra astacin-7 (HAS-7) is expressed from gland cells as an apical-distal gradient in the body column, peaking close beneath the tentacle zone. HAS-7 siRNA knockdown abrogates HyWnt3 proteolysis in the head tissue and induces a robust double axis phenotype, which is rescued by simultaneous HyWnt3 knockdown. Accordingly, double axes are also observed in conditions of increased Wnt levels as in transgenic actin::HyWnt3 and HyDkk1/2/4 siRNA treated animals. HyWnt3-induced double axes in Xenopus embryos could be rescued by co-injection of HAS-7 mRNA. Mathematical modelling combined with experimental promotor analysis indicate an indirect regulation of HAS-7 by beta-Catenin, expanding the classical Turing-type activator-inhibitor model.Our data suggest a negative regulatory function of Wnt processing astacin proteinases in the global patterning of the oral-aboral axis in Hydra.

Vital Marking of Single Cells in Developing Tissues: India Ink Injection to Trace Tissue Movements in Hydra

1973 ◽  
Vol 13 (3) ◽  
pp. 651-661 ◽  
Author(s):  
R. D. CAMPBELL
Keyword(s):  
Single Cells ◽  
Carbon Particle ◽  
The Body ◽  
Entire Body ◽  
Black Dot ◽  
Symbiotic Algae ◽  
India Ink ◽  
Marked Cell ◽  
Endodermal Cells ◽  
Body Column

A new vital marking procedure was devised, studied, and applied to the phenomenon of hydra column tissue movements. The method involves injecting colloidal carbon (India ink) into the ectodermal epithelium of hydra. The carbon is taken up specifically by epithelial cells and packed into lysosome residual bodies. Each marked cell is then identifiable by its aggregated carbon particle, which appears as a black dot; this is passed to a daughter cell during cell division. Using this method to stain vitally the ectoderm of the green hydra, Chlorohydra viridissima, whose endodermal cells were marked by symbiotic algae, the relative movements of ectoderm and endoderm along the body column were analysed. Ectoderm and endoderm move in different directions or at different rates in the top quarter of the gastric column, but move together in the lower part of the column. This indicates that some epithelial cell movements involve cells migrating relative to the mesoglea; other movements involve translocation of the entire body wall, including ectoderm, mesoglea and endoderm.

scholarly journals Staphylococcus-associated acute glomerulonephritis in a patient with dermatomyositis

2021 ◽  
Vol 14 (1) ◽  
pp. e236695 ◽  
Author(s):  
Rasmi Ranjan Sahoo ◽  
Sourav Pradhan ◽  
Akhil Pawan Goel ◽  
Anupam Wakhlu
Keyword(s):  
Infective Endocarditis ◽  
Kidney Biopsy ◽  
Kidney Injury ◽  
Staphylococcal Infection ◽  
Left Knee ◽  
The Body ◽  
Acute Glomerulonephritis ◽  
Disease Course ◽  
Rheumatological Disease ◽  
Per Se

Staphylococcus-associated glomerulonephritis (SAGN) occurs as a complication of staphylococcal infection elsewhere in the body. Dermatomyositis (DM) can be associated with glomerulonephritis due to the disease per se. We report a case of a 40-year-old male patient with DM who presented with acute kidney injury, and was initially pulsed with methylprednisolone for 3 days, followed by dexamethasone equivalent to 1 mg/kg/day prednisolone. He was subsequently found to have SAGN on kidney biopsy along with staphylococcus bacteraemia and left knee septic arthritis. With proof of definitive infection, intravenous immunoglobulin 2 g/kg over 2 days was given and steroids were reduced. He was treated with intravenous vancomycin. With treatment, the general condition of the patient improved. On day 38, he developed infective endocarditis and died of congestive heart failure subsequently. Undiagnosed staphylococcal sepsis complicating a rheumatological disease course can lead to complications like SAGN, infective endocarditis and contribute to increased morbidity and mortality, as is exemplified by our case.

Three digestive movements in Hydra regulated by the diffuse nerve net in the body column

2004 ◽  
Vol 190 (8) ◽  
Author(s):  
Hiroshi Shimizu ◽  
Osamu Koizumi ◽  
Toshitaka Fujisawa
Keyword(s):  
The Body ◽  
Nerve Net ◽  
Body Column

Axis-inducing activities and cell fates of the zebrafish organizer

Development ◽  
2000 ◽  
Vol 127 (16) ◽  
pp. 3407-3417 ◽  
Author(s):  
L. Saude ◽  
K. Woolley ◽  
P. Martin ◽  
W. Driever ◽  
D.L. Stemple
Keyword(s):  
Organizer Region ◽  
Complete Removal ◽  
Floor Plate ◽  
Significant Loss ◽  
Cell Fates ◽  
Deep Tissue ◽  
Head Formation ◽  
Prechordal Plate ◽  
Embryonic Shield ◽  
Organizer Activity

We have investigated axis-inducing activities and cellular fates of the zebrafish organizer using a new method of transplantation that allows the transfer of both deep and superficial organizer tissues. Previous studies have demonstrated that the zebrafish embryonic shield possesses classically defined dorsal organizer activity. When we remove the morphologically defined embryonic shield, embryos recover and are completely normal by 24 hours post-fertilization. We find that removal of the morphological shield does not remove all goosecoid- and floating head-expressing cells, suggesting that the morphological shield does not comprise the entire organizer region. Complete removal of the embryonic shield and adjacent marginal tissue, however, leads to a loss of both prechordal plate and notochord. In addition, these embryos are cyclopean, show a significant loss of floor plate and primary motorneurons and display disrupted somite patterning. Motivated by apparent discrepancies in the literature we sought to test the axis-inducing activity of the embryonic shield. A previous study suggested that the shield is capable of only partial axis induction, specifically being unable to induce the most anterior neural tissues. Contrary to this study, we find shields can induce complete secondary axes when transplanted into host ventral germ-ring. In induced secondary axes donor tissue contributes to notochord, prechordal plate and floor plate. When explanted shields are divided into deep and superficial fragments and separately transplanted we find that deep tissue is able to induce the formation of ectopic axes with heads but lacking posterior tissues. We conclude that the deep tissue included in our transplants is important for proper head formation.

Concentration and Visualization Techniques in Buddhist Meditation

2021 ◽  
Author(s):  
Nobuyoshi Yamabe
Keyword(s):  
Fifth Century ◽  
The Body ◽  
Early Form ◽  
Significant Development ◽  
Buddhist Meditation ◽  
Esoteric Buddhism ◽  
Reflective Thought ◽  
Visual Approach ◽  
Per Se ◽  
Visualization Techniques

This chapter outlines the early form and development of Buddhist meditation. First, it discusses the “application of mindfulness,” especially “mindfulness of the body,” which can be largely classified into two types of practice. One is “mindfulness per se,” without reflective thought, and the other is a more reflective or visual approach. “Mindfulness per se” (in particular, mindful breathing) was transmitted to East Asia and remains the cardinal method there. The chapter discusses close ties between traditional mindfulness and Japanese Sōtō practice. It then moves on to describe meditation on the decomposition of a corpse, which is a representative form of the more reflective and visual type of practice, involving the observation of a dead body in its stages of decomposition. This is found in early scriptures. Later texts came to teach a more elaborate method of “grasping the images” of a corpse. A notable development in visualization is that the images seen by the practitioner came to include ones that were more enigmatic. The discussion finally turns to another significant development in Buddhist meditation, one which involves Buddha visualization. Its undeveloped form is found in early Mahayana sutras, but a fully developed version employing statues as aides for visualization is found in later meditation texts from the fifth century onward. This type of visualization was inherited by Esoteric Buddhism and is still practiced today.

Taxonomic description and 3D modelling of a new species of myzostomid (Annelida, Myzostomida) associated with black corals from Madagascar

Zootaxa ◽  
2017 ◽  
Vol 4244 (2) ◽  
pp. 277 ◽  
Author(s):  
LUCAS TERRANA ◽  
IGOR EECKHAUT
Keyword(s):  
New Species ◽  
Phylogenetic Analyses ◽  
Three Dimensional ◽  
Close Relation ◽  
Ventral Side ◽  
Middle Part ◽  
The Body ◽  
Taxonomic Description ◽  
Black Corals ◽  
Organ Systems

Eenymeenymyzostoma nigrocorallium n. sp. is the first species of myzostomid worm associated with black corals to be described. Endoparasitic specimens of E. nigrocorallium were found associated with three species of antipatharians on the Great Reef of Toliara. Individuals inhabit the gastrovascular ducts of their hosts and evidence of infestation is, most of the time, not visible externally. Phylogenetic analyses based on 18S rDNA, 16S rDNA and COI data indicate a close relation to Eenymeenymyzostoma cirripedium, the only other species of the genus. The morphology of E. nigrocorallium is very unusual compared to that of the more conventional E. cirripedium. The new species has five pairs of extremely reduced parapodia located on the body margin and no introvert, cirri or lateral organs. Individuals are hermaphroditic, with the male and female gonads both being located dorsally in the trunk. It also has a highly developed parenchymo-muscular layer on the ventral side, and the digestive system lies in the middle part of the trunk. A three-dimensional digital model of this worm’s body plan has been constructed whereby the external morphology and in toto views of the observed organ systems (nervous, digestive and reproductive) can be viewed on-screen: http://doi.org/10.13140/RG.2.2.17911.21923. 

Endodontic Materials: Reactor Response

1988 ◽  
Vol 2 (1) ◽  
pp. 25-28 ◽  
Author(s):  
I.A. Mjör
Keyword(s):  
Side Effects ◽  
Review Paper ◽  
Defense Mechanism ◽  
The Body ◽  
Endodontic Treatment ◽  
Bridge Formation ◽  
Per Se ◽  
Apical Area

This discussion of a review paper on endodontic materials focuses on the need for standardization of this group of materials, including clinical and biological investigations. It was concluded that the search for endodontic materials that are both adhesive to dentin and insoluble must continue. When such materials become available, the defense mechanism of the body would take care of the healing per se. This approach as well as techniques and materials which induce dentin bridge formation in the apical area were considered feasible for improving endodontic treatment. The need to report side-effects of endodontic materials was stressed, and it was suggested that such reports should be mandatory for clinicians and for manufacturers of endodontic materials.

What is Distinctive about Methodist Ecclesiology? A Response to Papers by Miriam Haar, Justus Hunter and Robert Martin

Ecclesiology ◽  
2013 ◽  
Vol 9 (1) ◽  
pp. 66-74
Author(s):  
Kenneth Wilson
Keyword(s):  
Catholic Church ◽  
Church Of England ◽  
Roman Catholic ◽  
The Body ◽  
Roman Catholic Church ◽  
Body Of Christ ◽  
Per Se ◽  
The Church

Does Methodism want a distinctive ecclesiology? British Methodism assumes its ecclesiology from the Church of England which explains its lack of ecclesiological thinking, its genuine desire for reunification, and indeed its focus on ecclesia in actu. But there can be no ecclesia in actu apart from ecclesia per se. Being and doing are one in God. The Church, grounded in the dynamic being of God in Trinity, celebrates in the action of the Eucharist the wholeness of God’s presence with his world. Proleptically the Church includes the whole of creation and all people. Hence, when as the Body of Christ we pray the Our Father with our Lord, we pray on behalf of all, not just for ourselves. But what then do we mean by apostolicity? Perhaps in Methodism we would be well occupied exploring more keenly with the Roman Catholic Church what we each mean by being a society within the church. Outler may have been right when he opined that Methodism needed a Catholic Church within which to be church.

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