Hydra regeneration and epitheliopeptides

  title={Hydra regeneration and epitheliopeptides},
  author={Toshitaka Fujisawa},
  journal={Developmental Dynamics},
  • T. Fujisawa
  • Published 1 February 2003
  • Biology
  • Developmental Dynamics
Hydra has been well known for over 200 years for its remarkable regenerative capacity. In addition to small pieces excised from the body, reaggregates of dissociated single cells can also regenerate. Although the cellular events involved in the regeneration process have been well characterized, the underlying molecular mechanisms are yet to be uncovered. Recently, however, transcription factors and signaling molecules, both proteins and short peptides, have been identified and their role… 

Cell plasticity in homeostasis and regeneration

The freshwater Hydra polyp provides a unique model system to study the intricate relationships between the mechanisms that regulate the maintenance of homeostasis, even in extreme conditions and the reactivation of developmental programs after bisection or during budding.

Generic and context-dependent gene modulations during Hydra whole body regeneration

A transcriptome-wide comparative analysis of apical and basal regeneration after decapitation and mid-gastric bisection is presented, augmented with a characterization of positional and cell-type expression patterns in non-regenerating animals.

Deer antlers: a zoological curiosity or the key to understanding organ regeneration in mammals?

Very little is known about the molecular machinery required for antler regeneration, although there is evidence that developmental signalling pathways with pleiotropic functions are important and that novel ‘antler‐specific’ molecules may not exist.

Head regeneration in wild-type hydra requires de novo neurogenesis

The function of the ParaHox gsx homolog gene, cnox-2, which is a specific marker for bipotent neuronal progenitors expressed in cycling interstitial cells that give rise to apical neurons and gastric nematoblasts, is tested in wild-type hydra and acts as an upstream regulator of the neuronal and nematocyte differentiation pathways.


The red spotted newt is able to regenerate areas of the brain that are normally devoid of proliferating cells, and the neurotransmitter dopamine inhibits the proliferation of DA progenitor cells in a feedback-like manner, which could aid the development of techniques to evoke brain regeneration in humans.

Unraveling Tissue Regeneration Pathways Using Chemical Genetics*

Results indicate that signaling from exogenous glucocorticoids impairs blastema formation and limits regenerative capacity through an acute inflammation-independent mechanism, and demonstrate the feasibility of exploiting chemical genetics to define the pathways that govern vertebrate regeneration.

Hydra Peptide Project 1993–2007

  • T. Fujisawa
  • Biology
    Development, growth & differentiation
  • 2008
A systematic screening of peptide signaling molecules in Hydra magnipapillata (the Hydra Peptide Project) was launched in 1993 and at least the first phase of the project ended in 2007, and many novel neuropeptides were identified.

Subcellular localization of the epitheliopeptide, Hym-301, in hydra

The intracellular localization of Hym-301 in hydra is examined by using immunohistochemical and immunogold electron-microscopic analyses and it is found that the pattern of distribution of mature peptide is slightly different from that of its mRNA, and that it is stored in vesicles located adjacent to the cell membrane.



Epithelial cells in nerve-free hydra produce morphogenetic substances

It is shown that epithelial cells in hydra have the potential to produce head activator and other morphogenetic factors, but that this property is repressed in the presence of nerves.

Enhancement of foot formation in Hydra by a novel epitheliopeptide, Hym-323.

Results suggest that Hym-323 is a peptide involved in a foot-patterning process in Hydra, and that the foot activation potential was increased in the peptide-treated tissue.

Polyps, peptides and patterning

  • T. BoschT. Fujisawa
  • Biology, Chemistry
    BioEssays : news and reviews in molecular, cellular and developmental biology
  • 2001
The abundance of peptides in Hydra raises the question of whether, in early metazoan evolution, cell–cell communication was based mainly on these small molecules rather than on the growth‐factor‐like cytokines that control differentiation and development in higher animals.

Development of Hydra lacking nerve and interstitial cells.

It is concluded that hydra consisting only of epithelial cells are capable of essentially normal development and only in some quantitative aspects do I cell-free hydra develop abnormally.

Genetic analysis of developmental mechanisms in hydra

A chimaeric strain of hydra was produced by combining interstitial cells (and thus their differentiation products, nerve cells and nematocytes) of reg-16 hydra with epithelial cells of another strain which is capable of normal regeneration, suggesting that regeneration deficiency in reg- 16 is due to a defective polarity gradient.

Epithelial morphogenesis in hydra requires de novo expression of extracellular matrix components and matrix metalloproteinases.

The correlation of loss of the ECM, cell shape changes and subsequent de novo biogenesis of matrix and matrix-associated components were all functionally coupled by antisense experiments in which translation of HLM-beta1 and HMMP was blocked and head regeneration was reversibly inhibited.

Genetic analysis of developmental mechanisms in hydra: III. Characterization of a regeneration deficient strain

A chimaeric strain of hydra was produced by combining interstitial cells (and thus their differentiation products, nerve cells and nematocytes) of reg-16 hydra with epithelial cells of another strain which is capable of normal regeneration, suggesting that regeneration deficiency in reg- 16 is due to a defective polarity gradient.

Isolation and characterization of two new morphogenetically active peptides from Hydra vulgaris.

The data obtained by biological and radioimmunoassays show that the shorter peptide, pedin, is an excellent candidate for a major component of the 'foot-activating potential'.

Hydra regeneration from recombined ectodermal and endodermal tissue. II. Differential stability in the ectodermal and endodermal epithelial organization.

It is suggested that this dynamic nature of the hydra tissue, particularly the high plasticity of the endodermal epithelial sheet organization, may be an important element for the high regenerative capacity of this organism.

Genetic analysis of developmental mechanisms in Hydra. II. Isolation and characterization of an interstitial cell-deficient strain.

A mutant strain of Hydra magnipapillata was isolated that contained no interstitial cells, nerve cells or nematocytes and was very similar to the interstitial cell-deficient strain produced by Campbell (1976) by means of colchicine.