Biology of Hydra

Biology of Hydra covers eight areas of Hydra biology, particularly, its behavior and ecology; polarity; gastrodermal and epidermal regeneration; differentiation of nervous elements; cell proliferation and morphogenesis; and mesoglea.
This book describes, in particular, the various aspects of Hydra's behavior, not obvious in casual observation, as well as the animal's feeding and digestion. It also looks into the contribution of interstitial cells to the regenerative process in Hydra; the ultrastructural changes during dedifferentiation and redifferentiation in the regenerating, isolated gastrodermis; regeneration from isolated epidermal explants; and regeneration of a Hydra containing no interstitial cells from an isolated basal disc. Furthermore, the book explains the grafting of the gastrodermis of Hydra viridis to the epidermis of Hydra pseudoligactis, and the results of such agraft on two animals sectioned for histological study. It examines the role of the neoblast in regeneration and the ultrastructure of Hydra's nervous system. The book also explores Hydra's growth and the contribution of cell proliferation to net growth and maintenance of form.

Contenu

List of Contributors
Preface
In Memoriam
Part I Behavior of Hydra
Chapter 1. Behavior
I. Introduction
II. Locomotory Activity
III. Feeding Behavior
IV. Response to External Stimulation
V. Summary
References
Chapter 2. Feeding and Digestion
I. Food Capture
II. Ingestion of Food
III. Digestion
References
Part II Ecology of hydra
Chapter 3. Ecology
I. Introduction
II. Some Preliminary Considerations
III. Planktonic Phases
IV. Environmental Crises and Hydrid Defenses
V. Energetic Capital Investments of Hydrid Populations
VI. Conclusion
References
Part III Polarity in Hydra
Chapter 4. The Developmental Significance of Interstitial Cells during Regeneration
and Budding
I. Introduction
II. Experimental Analysis of Regeneration and Budding in Hydra Treated with Nitrogen Mustard to Selectively Eliminate Interstitial Cells
III. Theoretical Aspects of Regeneration and Budding in Animals Devoid of Interstitial Cells
References
Chapter 5. Expression and Maintenance of Organismic Polarity
I. Review of Evidence Accumulated at Various Levels of Biological Organization
II. Growth Patterns
III. Theories Analyzing the Control of Polarized Form
IV. Prospectus
References
Part IV Gastrodermal Regeneration in hydra
Chapter 6. Ultrastructural Changes during Dedifferentiation and Redifferentiation in the Regenerating, Isolated Gastrodermis
I. Introduction
II. Epidermal Differentiation - Dedifferentiation and Redifferentiation
III. Epidermal Differentiation - Transformation
IV. Gastrodermis
V. Gastric Cavity
VI. Formation of the Mesoglea
VII. Summary and Conclusions
References
Part V Epidermal Regeneration in Hydra
Chapter 7. Regeneration from Isolated Epidermal Explants
I. Introduction
II. Methods
III. Results
IV. Discussion
V. Summary
References
Chapter 8. Epithelial-Muscle Cells
Text
References
Chapter 9. Regeneration of a Hydra Containing No Interstitial Cells from an Isolated Basal Disc
I. Introduction
II. Materials and Methods
III. Results
IV. Discussion
References
Chapter 10. Interspecific Grafting of Cell Layers
I. Introduction
II. Methods
III. Results and Discussion
References
Chapter 11. Regeneration of a Complete Hydra from a Single, Differentiated Somatic Cell Type
I. Introduction
II. Normal Regeneration
III. Dedifferentiation of Specialized Cell Types into I-Cells
IV. Epidermal Regeneration
V. Regeneration of Animals Lacking I-Cells
VI. Regeneration of Whole Hydras from Explants Consisting Solely of Epitheliomuscular Cells
VII. Discussion
References
Part VI Differentiation of Nervous Elements in Hydra
Chapter 12. Ultrastructure of Neurosensory Cell Development
I. Introduction and Historical Review
II. Neurosensory Cell Development
III. The Mature Neurosensory Cell
IV. Fate of Neurosensory Cells
References
Chapter 13. Ultrastructure of Ganglionic Cell Development
I. Introduction
II. Early Development
III. Later Development
IV. Mature Ganglionic Cell
References
Chapter 14. Structure of Neurosecretory Cells with Special Reference to the Nature of the Secretory Product
I. Introduction
II. The Neurosecretory Cell
III. Mechanisms of Neurosecretory Release
IV. Nature of Neurosecretory Material
References
Part VII Cell Proliferation and Morphogenesis in Hydra
Chapter 15. Organismal Growth and the Contribution of Cell Proliferation to Net Growth and Maintenance of Form
Part I. Organismal Growth
Part II. The Contribution of Cell Proliferation to Net Growth and Maintenance of Form
References
Part VIII The Mesoglea of Hydra
Chapter 16. The Mesoglea
I. Mesoglea as Connective Tissue
II. Physicochemical Structure of Mesoglea
III. Mesoglea as a Dynamic Structure
IV. Mesoglea Origin
V. Morphogenic Role
References
Author Index
Subject Index