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

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.

Genetic analysis of developmental mechanisms in Hydra. IV. Characterization of a nematocyst-deficient strain

1978 ◽  
Vol 30 (1) ◽  
pp. 175-185 ◽  
Author(s):  
T. Fujisawa ◽  
T. Sugiyama
Keyword(s):  
Genetic Analysis ◽  
Normal Level ◽  
The Body ◽  
Normal Rate ◽  
Wild Type ◽  
Head Region ◽  
Developmental Defects ◽  
Developmental Mechanisms ◽  
Body Column

The authors have previously found that mutant hydra strains showing various types of developmental defects can be isolated through sexual inbreeding of wild hydra. One such defective strain, called nem-4, contains virtually no stenoteles, one of the four types of nematocysts present in hydra, in its tentacles. However, stenoteles are present at a normal level in the body column of this strain, and they are turned over also at a normal rate. Grafting experiments between the head region of nem-4 hydra and the body column of wild type hydra (and vice versa) showed that wild type stenotele nematocytes can move into nem-4 tentacles but that nem-4 stenotele nematocytes can not move into the wild type tentacles. These observations suggest that the stenotele nematocytes are produced normally by differentiation from the interstitial cells in the body column of nem-4 hydra, but that they are somehow prevented from migrating into the tentacles in this strain.

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 Decreased ligand affinity rather than glucocorticoid receptor down-regulation in patients with endogenous Cushing's syndrome

2000 ◽  
pp. 472-476 ◽  
Author(s):  
NA Huizenga ◽  
WW De Herder ◽  
JW Koper ◽  
P de Lange ◽  
D AJ v Lely ◽  
...  
Keyword(s):  
Glucocorticoid Receptor ◽  
Cushing’S Syndrome ◽  
Cushing's Syndrome ◽  
The Body ◽  
The Other ◽  
Down Regulation ◽  
Ligand Affinity ◽  
Other Hand ◽  
Receptor Number ◽  
Cortisol Levels

OBJECTIVE: Glucocorticoids (GCs) serve a variety of important functions throughout the body. The synthesis and secretion of GCs are under the strict influence of the hypothalamo-pituitary-adrenal axis. The mechanisms of action of GCs are mediated by the intracellular glucocorticoid receptor (GR). Over the years, many studies have been performed concerning the regulation of GR expression by GC concentrations. METHODS: In the present study, we determined the characteristics of the GR in peripheral mononuclear blood leukocytes (PBML) from thirteen patients with endogenous Cushing's syndrome and fifteen control subjects, using a whole cell dexamethasone binding assay. Furthermore, cortisol concentrations were determined in order to investigate a possible relationship between serum cortisol levels and receptor characteristics. RESULTS: There were no differences in mean receptor number between patients and controls. On the other hand, a significantly lower ligand affinity was identified in cells from patients with Cushing's syndrome compared with controls. A complete normalisation of the ligand affinity was observed after treatment in the only patient tested in this respect, whereas the receptor number was not affected. In patients, there was a statistically significant negative correlation between cortisol concentrations and ligand affinity, which was not found in controls. CONCLUSION: Receptor down-regulation does not occur in PBML from patients with endogenous Cushing's syndrome. On the other hand, there seems to be a diminished ligand affinity which possibly reflects receptor modification in response to exposure to the continuously high cortisol levels in patients with Cushing's syndrome. This assumption is substantiated by the fact that in one patient a normalisation of the ligand affinity after complete remission of the disease was seen.

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

scholarly journals Opposite asymmetries of face and trunk and of kissing and hugging, as predicted by the axial twist hypothesis

2019 ◽  
Author(s):  
Marc HE de Lussanet
Keyword(s):  
Bilateral Symmetry ◽  
Optic Chiasm ◽  
Early Embryo ◽  
The Body ◽  
Head Region ◽  
Evolutionary Selection ◽  
Left Handed ◽  
Secondary Feature ◽  
Half Turn ◽  
Axial Twist

The contralateral organization of the forebrain and the crossing of the optic nerves in the optic chiasm represent a long-standing conundrum. According to the Axial Twist Hypothesis (ATH) the rostral head and the rest of the body are twisted with respect to each other to form a left-handed half turn. This twist is the result, mainly, of asymmetric, twisted growth in the early embryo. Evolutionary selection tends to restore bilateral symmetry. Since selective pressure will decrease as the organism approaches symmetry, we expected a small control error in the form of a small, residual right-handed twist. We found that the mouth-eyes-nose (rostral head) region shows a left-offset with respect to the ears (posterior head) by up to 0.8° (P<0.01, Bonferroni-corrected). Moreover, this systematic aurofacial asymmetry was larger in young children (on average up to 3°) and reduced with age. Finally, we predicted and found a right-sided bias for hugging (78%) and a left-sided bias for kissing (69%). Thus, all predictions were confirmed by the data. These results are all in support of the ATH, whereas the pattern of results is not explained by existing alternative theories. As of the present results, the ATH is the first theory for the contralateral forebrain and the optic chiasm whose predictions have been tested empirically. We conclude that humans (and all other vertebrates) are fundamentally asymmetric, both in their anatomy and their behavior. This supports the thesis that the approximate bilateral symmetry of vertebrates is a secondary feature, despite their being bilaterians.

scholarly journals Intra-specific morphological and morphometric variability of Radopholus similis (Cobb, 1893) Thorne, 1949

2018 ◽  
Vol 10 (3) ◽  
pp. 841-846 ◽  
Author(s):  
S. Roy ◽  
K Roy ◽  
S. Sarkar ◽  
A Rathod ◽  
J. Hore
Keyword(s):  
The Body ◽  
Radopholus Similis ◽  
Body Width ◽  
Head Region ◽  
Morphometric Characters ◽  
Lateral Field ◽  
Oesophageal Gland ◽  
Morphometric Features ◽  
Basal Bulb ◽  
Stylet Length

All the root inhabiting migratory endoparasitic nematode populations of Radopholus procured from banana crop of Vellayani, Thiruvananthapuram, Kerala were identified as Radopholus similis. Heat killed females were straight to slightly ventrally curved posteriorly. Female’s head was low, rounded, continuous or slightly setoff with the body contour. Females were 500-660 µm long and were comparatively longer than males. Males had button shaped head set off by a constriction; female with three to five lip annuli, four crenate and areolated lateral incisures, stylet 14-18 µm long with rounded knobs, vulva post-equatorial (58%), sometimes with slight protuberant lips, ovary paired and equally developed, oesophageal gland overlapped the intestine dorsally, tail elongate-conoid with narrowly rounded terminus. The stylet length (µm), width of stylet knob (µm), distance of excretory pore from anterior end (µm), distance from head to basal bulb (µm), lateral field structure, shape of stylet knob, head region, position of phasmid, tail shape with its terminus, morphometric values like m%, o% and v% and a, c and c´ ratios of females were stable (CV<12%) features. There is an existence of intra-specific variability in the morphological and morphometric features of R. similis. The main morphological diversity was observed with P% of male and female, b ratio of female and stylet length, distance of DEGO from stylet base, o% and T% of male. All the root inhabiting migratory endoparasitic nematode populations of Radopholus Thorne, 1949 procured from banana of Vellayani, Thiruvananthapuram, Kerala were identified as Radopholus similis (Cobb, 1893) Thorne, 1949. A high degree of intra-specific morphometric variability was observed with regard to the total body length (µm), body width (µm), stylet length (µm), distance of dosrsal oesophageal gland orifice (DEGO) from stylet base (µm), number of lip annuli, lip height (µm), distance from head to basal bulb (µm), distance of anus from anterior end (µm), tail length (µm), anal body width (µm), distance of phasmid from tail terminus (µm), number of lateral lines, width of lateral field (µm), b ratio and P % among females of R. similis. Morphometric features like m%, o% and v% of females of R. similis showed least variability. These can be considered as the stable morphometric characters for discrimination of females of R. similis. Ratios like ‘a’ and ‘c’ of females of R. similis were found moderately variable. The morphometric feature and of male i.e. distance from head to basal bulb (µm) was found least variable; while number of lip annuli and spicule length (µm) were moderately variable.  

scholarly journals Wnt Signaling Regulates the Lineage Differentiation Potential of Mouse Embryonic Stem Cells through Tcf3 Down-Regulation

PLoS Genetics ◽  
2013 ◽  
Vol 9 (5) ◽  
pp. e1003424 ◽  
Author(s):  
Yaser Atlasi ◽  
Rubina Noori ◽  
Claudia Gaspar ◽  
Patrick Franken ◽  
Andrea Sacchetti ◽  
...  
Keyword(s):  
Stem Cells ◽  
Embryonic Stem Cells ◽  
Wnt Signaling ◽  
Embryonic Stem ◽  
Mouse Embryonic Stem Cells ◽  
Down Regulation ◽  
Differentiation Potential ◽  
Lineage Differentiation

scholarly journals Perlecan regulates bidirectional Wnt signaling at the Drosophila neuromuscular junction

2013 ◽  
Vol 200 (2) ◽  
pp. 219-233 ◽  
Author(s):  
Keisuke Kamimura ◽  
Kohei Ueno ◽  
Jun Nakagawa ◽  
Rie Hamada ◽  
Minoru Saitoe ◽  
...  
Keyword(s):  
Drosophila Melanogaster ◽  
Neuromuscular Junction ◽  
Heparan Sulfate ◽  
Wnt Signaling ◽  
Nuclear Import ◽  
Heparan Sulfate Proteoglycans ◽  
Down Regulation ◽  
Bidirectional Signaling ◽  
Synaptic Boutons ◽  
Signaling Activity

Heparan sulfate proteoglycans (HSPGs) play pivotal roles in the regulation of Wnt signaling activity in several tissues. At the Drosophila melanogaster neuromuscular junction (NMJ), Wnt/Wingless (Wg) regulates the formation of both pre- and postsynaptic structures; however, the mechanism balancing such bidirectional signaling remains elusive. In this paper, we demonstrate that mutations in the gene of a secreted HSPG, perlecan/trol, resulted in diverse postsynaptic defects and overproduction of synaptic boutons at NMJ. The postsynaptic defects, such as reduction in subsynaptic reticulum (SSR), were rescued by the postsynaptic activation of the Frizzled nuclear import Wg pathway. In contrast, overproduction of synaptic boutons was suppressed by the presynaptic down-regulation of the canonical Wg pathway. We also show that Trol was localized in the SSR and promoted postsynaptic accumulation of extracellular Wg proteins. These results suggest that Trol bidirectionally regulates both pre- and postsynaptic activities of Wg by precisely distributing Wg at the NMJ.

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