Expression of Cnox-2, a HOM/HOX homeobox gene in hydra, is correlated with axial pattern formation

Development ◽  
1993 ◽  
Vol 117 (2) ◽  
pp. 657-667 ◽  
Author(s):  
M.A. Shenk ◽  
H.R. Bode ◽  
R.E. Steele
Keyword(s):  
Pattern Formation ◽  
Epithelial Cells ◽  
Homeobox Gene ◽  
Specific Pattern ◽  
The Body ◽  
Body Axis ◽  
Hydra Vulgaris ◽  
Coordinate Reduction ◽  
High Level ◽  
Body Column

Cnox-2 is a HOM/HOX homeobox gene that we have identified in the simple metazoan Hydra vulgaris (Cnidaria: Hydrozoa). Cnox-2 is most closely related to anterior members of the Antennapedia gene complex from Drosophila, with the greatest similarity to Deformed. The Cnox-2 protein is expressed in the epithelial cells of adult hydra polyps in a region-specific pattern along the body axis, at a low level in the head and at a high level in the body column and the foot. The expression pattern of Cnox-2 is consistent with a role in axial pattern formation. Alteration of hydra axial patterning by treatment with diacylglycerol (DAG) results in an increase of head activation down the body column and in a coordinate reduction of Cnox-2 expression in epithelial cells in ‘head-like’ regions. These results suggest that Cnox-2 expression is negatively regulated by a signaling pathway acting through protein kinase C (PKC), and that the varying levels of expression of Cnox-2 along the body axis have the potential to result in differential gene expression which is important for hydra pattern formation.

scholarly journals Polarized entry and release of Junín virus, a New World arenavirus

2005 ◽  
Vol 86 (5) ◽  
pp. 1475-1479 ◽  
Author(s):  
Sandra M. Cordo ◽  
Maximiliano Cesio y Acuña ◽  
Nélida A. Candurra
Keyword(s):  
Epithelial Cells ◽  
Membrane Surface ◽  
The Body ◽  
Apical Plasma Membrane ◽  
Apical Surface ◽  
High Level Expression ◽  
Virus Family ◽  
Junin Virus ◽  
High Level ◽  
Junín Virus

Junín virus (JUNV), the causative agent of Argentine haemorrhagic fever, is a human pathogen that naturally enters the body through the epithelial cells of the respiratory and digestive tracts. The interaction of JUNV with two types of polarized epithelial cultures, Vero C1008 and A549, was investigated. Radioactive virus-binding assays showed that JUNV infects polarized lines preferentially through the apical surface. High-level expression of viral nucleoprotein was detected in polarized cell lines infected through the apical domain. Virus production from apical media was about 100-fold higher than that found into the basolateral medium. Confocal-immunofluorescence analysis revealed high-level expression of glycoprotein at the apical-membrane surface. Disruption of the microtubule network by colchicine impaired JUNV vectorial release. This is the first study to analyse the interaction between a member of the virus family Arenaviridae and polarized epithelial cells, showing preferential entry and release from the apical plasma membrane.

The novel signal peptides, pedibin and Hym-346, lower positional value thereby enhancing foot formation in hydra

Development ◽  
1999 ◽  
Vol 126 (3) ◽  
pp. 517-524 ◽  
Author(s):  
A. Grens ◽  
H. Shimizu ◽  
S.A. Hoffmeister ◽  
H.R. Bode ◽  
T. Fujisawa
Keyword(s):  
Extended Period ◽  
The Body ◽  
Signal Peptides ◽  
The Novel ◽  
Direct Measure ◽  
Hydra Vulgaris ◽  
Hydra Magnipapillata ◽  
Body Column ◽  
Positional Value ◽  
Tissue Form

Signaling molecules affecting patterning processes are usually proteins and rarely peptides. Two novel peptides, pedibin and Hym-346, that are closely related to one another have been isolated from Hydra vulgaris and Hydra magnipapillata. Several experiments indicate that both cause a reduction in the positional value gradient, the principle patterning process governing the maintenance of form in the adult hydra. The peptides cause an increase in the rate of foot regeneration following bisection of the body column. Treatment of animals with either peptide for an extended period of time resulted in an apical extension of the range of expression of CnNk-2 along the body column. Such an extension is correlated with a decrease in positional value. Transplantation of tissue treated with Hym-346 results in an increase in the fraction forming feet, and aggregates derived from Hym-346 tissue form more feet and fewer heads. The latter two experiments provide a direct measure of the lowering of positional value in the treated tissue. These results suggest that peptides play signaling roles in patterning processes in cnidaria and, plausibly, in more complex metazoans as well.

scholarly journals How Dickkopf molecules and Wnt/beta-catenin interplay to self-organise the Hydra body axis

2021 ◽  
Author(s):  
Moritz Mercker ◽  
Alexey Kazarnikov ◽  
Anja Tursch ◽  
Suat Özbek ◽  
Thomas W Holstein ◽  
...  
Keyword(s):  
Pattern Formation ◽  
Numerical Study ◽  
Expression Patterns ◽  
Stem Cell Differentiation ◽  
Wnt Signalling ◽  
The Body ◽  
Body Axis ◽  
Beta Catenin ◽  
Mutual Inhibition ◽  
Activator Inhibitor

The antagonising interplay between canonical Wnt signalling and Dickkopf (Dkk) molecules has been identified in various processes involved in tissue organisation, such as stem cell differentiation and body-axis formation. Disruption of the interplay between these molecules is related to several diseases in humans. However, the detailed molecular mechanisms of the β-catenin/Wnt-Dkk interplay leading to robust formation of the body axis remain elusive. Although the β-catenin/Wnt signalling system has been shown in the pre-bilaterian model organism Hydra to interact with two ancestral Dkks (HyDkk1/2/4-A and -C) to self-organise and regenerate the body axis, the observed Dkk expression patterns do not match any current pattern-formation theory, such as the famous activator-inhibitor model. To explore the function of Dkk in Hydra patterning process, we propose a new mathematical model which accounts for the two Dkks in interplay with HyWnt3/β-catenin. Using a systematic numerical study, we demonstrate that the chosen set of interactions is sufficient to explain it de novo body-axis gradient formation in Hydra. The presented mutual inhibition model goes beyond the classical activator-inhibitor model and shows that a molecular mechanism based on mutual inhibition may replace the local activation/long-range inhibition loop. The new model is validated using a range of perturbation experiments. It resolves several contradictions between previous models and experimental data, and provides an explanation for the interplay between injury response and pattern formation.

scholarly journals Differential expression of BMP antagonists, gremlin and noggin in hydra: antagonism between Wnt and BMP pathways

2019 ◽  
Author(s):  
Krishnapati Lakshmi Surekha ◽  
Samiksha Khade ◽  
Diptee Trimbake ◽  
Rohan Patwardhan ◽  
Siva Kumar Nadimpalli ◽  
...  
Keyword(s):  
Wnt Signaling ◽  
The Body ◽  
Head Region ◽  
Down Regulation ◽  
Hydra Vulgaris ◽  
Basal Disc ◽  
Bmp Pathway ◽  
Summary Statement ◽  
Bmp Antagonists ◽  
Body Column

AbstractMechanisms regulating BMP and Wnt signaling pathways have been widely studied in many organisms. One of the mechanisms by which these pathways are regulated is by binding of extracellular ligands. In the present study, we report studies with two BMP antagonists, gremlin and noggin from Hydra vulgaris Ind-Pune and demonstrate antagonistic relationship between BMP and Wnt pathways. Gremlin was ubiquitously expressed from the body column to head region except in the basal disc and hypostome. During budding, gremlin was expressed predominantly in the budding region suggesting a possible role in budding; this was confirmed in polyps with different stages of buds. Noggin, on the other hand, was predominantly expressed in the endoderm of hypostome, base of the tentacles, lower body column and at the basal disc in whole polyps. During budding, noggin was expressed at the sites of emergence of tentacles suggesting a role in tentacle formation. This was confirmed in alsterpaullone-treated polyps, which showed noggin expression as distinct spots where ectopic organizers and ectopic tentacles eventually formed. Using RT-PCR, we found that up-regulation of Wnt is accompanied with down-regulation of BMP5-8b demonstrating antagonism between the two pathways. Down-regulation of noggin and gremlin, however, occurred only after 24 h recovery. The data suggest that inhibition of BMP pathway by Wnt signaling in hydra does not directly involve noggin and gremlin. Our findings indicate that the BMP/Noggin antagonism evolved early for setting up and/or maintaining the head organizer while involvement of these BMP antagonists during vertebrate axial patterning are recent evolutionary acquisitions.Summary statementWe show that setting up of the Organizer by BMP/Noggin antagonism and role of BMP inhibitors in tissue patterning are evolutionarily ancient, probably arising for the first time in hydra

Embryonic origins of spleen asymmetry

Development ◽  
2000 ◽  
Vol 127 (1) ◽  
pp. 167-175 ◽  
Author(s):  
K.D. Patterson ◽  
T.A. Drysdale ◽  
P.A. Krieg
Keyword(s):  
Molecular Markers ◽  
Homeobox Gene ◽  
Subsequent Development ◽  
Splenic Tissue ◽  
Precursor Cells ◽  
The Body ◽  
Body Axis ◽  
Cellular Mechanisms ◽  
Immunologic Function ◽  
Organ Specific

The spleen is a vertebrate organ that has both hematopoietic and immunologic function. The embryonic origins of the spleen are obscure, with most studies describing the earliest rudiment of the spleen as a condensation of mesodermal mesenchyme on the left side of the dorsal mesogastrium. The development of spleen handedness has not been described previously, presumably because of the difficulty in assaying spleen position in the embryo and the lack of early, organ-specific molecular markers. Here we show that expression of the homeobox gene Nkx2-5 serves as a marker for spleen precursor tissue. Pre-splenic tissue is initially located in symmetric domains on both sides of the embryo but, during subsequent development, only the left side goes on to form the mature spleen. Therefore, the final location of the spleen on the left side of the body axis appears to result from preferential development of the spleen precursor cells on the left side of the embryo. Our studies indicate that the spleen and heart become asymmetric via different cellular mechanisms. Nkx2-5 may function locally as part of the laterality cascade, downstream of nodal and Pitx2, or it may direct asymmetric morphogenesis after laterality has been determined.

Inhibition of stenotele differentiation by head tissue in Hydra

1987 ◽  
Vol 87 (2) ◽  
pp. 315-322
Author(s):  
TOSHITAKA FUJISAWA
Keyword(s):  
Epithelial Cells ◽  
Interstitial Cell ◽  
Position Effect ◽  
Cell Lineage ◽  
The Body ◽  
Regional Pattern ◽  
Inhibitory Signal ◽  
Body Column ◽  
Head Regeneration

Stenotele nematocytes in Hydra are differentiated predominantly in the proximal regions and in gradually decreasing numbers in the more distal regions of the body column. To test whether this position effect is directed by an inhibitory signal from head tissue or by a stimulatory signal from foot tissue, head or foot tissue was laterally grafted from one animal to different positions on another animal. Heads grafted to proximal positions strongly inhibited stenotele differentiation, while the foot exhibited no stimulatory effect. In addition, tissue from gastric regions showed intermediate levels of inhibition. Thus, the inhibitory signal appears to be distributed in a gradient along the body column from head to foot. During head regeneration, the inhibitory signal disappeared abruptly from the distal tip and reappeared rapidly. These results suggest that the inhibitory signal is involved in generating the regional pattern of stenotele differentiation. Head tissue from epithelial hydra, which lacks the interstitial cell lineage, also inhibited stenotele differentiation, suggesting that the inhibitory signal is localized in epithelial cells.

scholarly journals Bacteria- and temperature-regulated peptides modulate β-catenin signaling inHydra

2020 ◽  
Vol 117 (35) ◽  
pp. 21459-21468
Author(s):  
Jan Taubenheim ◽  
Doris Willoweit-Ohl ◽  
Mirjam Knop ◽  
Sören Franzenburg ◽  
Jinru He ◽  
...  
Keyword(s):  
Pattern Formation ◽  
Abiotic Factors ◽  
The Body ◽  
Loss Of Function ◽  
Animal Development ◽  
Complex Interactions ◽  
Canonical Wnt ◽  
Secreted Peptides ◽  
The Impact ◽  
Body Column

Animal development has traditionally been viewed as an autonomous process directed by the host genome. But, in many animals, biotic and abiotic cues, like temperature and bacterial colonizers, provide signals for multiple developmental steps.Hydraoffers unique features to encode these complex interactions of developmental processes with biotic and abiotic factors, and we used it here to investigate the impact of bacterial colonizers and temperature on the pattern formation process. InHydra, formation of the head organizer involves the canonical Wnt pathway. Treatment with alsterpaullone (ALP) results in acquiring characteristics of the head organizer in the body column. Intriguingly, germfreeHydrapolyps are significantly more sensitive to ALP compared to control polyps. In addition to microbes, β-catenin–dependent pattern formation is also affected by temperature. Gene expression analyses led to the identification of two small secreted peptides, named Eco1 and Eco2, being up-regulated in the response to bothCurvibactersp., the main bacterial colonizer ofHydra, and low temperatures. Loss-of-function experiments revealed that Eco peptides are involved in the regulation of pattern formation and have an antagonistic function to Wnt signaling inHydra.

scholarly journals Hydra tropomyosin TROP1 is expressed in head-specific epithelial cells and is a major component of the cytoskeletal structure that anchors nematocytes

1994 ◽  
Vol 107 (6) ◽  
pp. 1403-1411 ◽  
Author(s):  
M.S. Lopez de Haro ◽  
L.M. Salgado ◽  
C.N. David ◽  
T.C. Bosch
Keyword(s):  
Epithelial Cells ◽  
Single Copy ◽  
The Body ◽  
High Rate ◽  
Gastric Tissue ◽  
Single Copy Gene ◽  
Cytoskeletal Structure ◽  
Copy Gene ◽  
Form Part ◽  
Body Column

A cDNA clone encoding a 253 amino acid tropomyosin was isolated from Hydra in a differential screen for head-specific genes. The Hydra tropomyosin gene, designated trop1, is a single copy gene, lacks introns and is strongly expressed in tentacle-specific epithelial cells. Analysis of protein synthesis in head and gastric tissue indicated a high rate of tropomyosin synthesis in head tissue. Immunolocalization of tropomyosin in tentacle tissue revealed a cushion-like tropomyosin-containing structure within battery cells at the base of nematocytes. The structure appears to form part of the cytoskeletal anchor for nematocytes. Tropomyosin cushions were also observed in epithelial cells along the body column, which contain mounted stenotele nematocytes.

Nutrients Mediate Bioavailability and Turnover of Proteins in Mammals

2019 ◽  
Vol 20 (7) ◽  
pp. 661-665
Author(s):  
Cunxi Nie ◽  
Fei Xie ◽  
Ning Ma ◽  
Yueyu Bai ◽  
Wenju Zhang ◽  
...  
Keyword(s):  
The Body ◽  
Biologically Active ◽  
Nitrogen Excretion ◽  
Dietary Proteins ◽  
Restricted Diet ◽  
Nutritional Interventions ◽  
Body Tissues ◽  
Utilization Of Protein ◽  
High Level ◽  
Protein Restricted Diet

As a major component of biologically active compounds in the body, proteins contribute to the synthesis of body tissues for the renewal and growth of the body. The high level of dietary protein and the imbalance of amino acid (AA) composition in mammals result in metabolic disorders, inefficient utilization of protein resources and increased nitrogen excretion. Fortunately, nutritional interventions can be an effective way of attenuating the nitrogen excretion and increasing protein utilization, which include, but are not limited to, formulating the AA balance and protein-restricted diet supplementing with essential AAs, and adding probiotics in the diet. This review highlights recent advances in the turnover of dietary proteins and mammal’s metabolism for health, in order to improve protein bioavailability through nutritional approach.

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