QUICK SEARCH:   [advanced] Author: Keyword(s):
Home     Help     Feedback     Subscriptions     Archive     Search     Table of Contents

This Article Figures Only Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Szczepanek, S. Articles by David, C. N. Search for Related Content PubMed PubMed Citation Articles by Szczepanek, S. Articles by David, C. N. Social Bookmarking                         What's this?

Poly--glutamate synthesis during formation of nematocyst capsules in Hydra

Zoologisches Institut, Ludwig-Maximilians-Universität München, Luisenstr. 14, 80333 München, Germany

Author for correspondence (e-mail: david{at}zi.biologie.uni-muenchen.de )

Accepted 5 November 2001

Nematocysts are explosive organelles found in all Cnidaria. Explosion of nematocyst capsules is driven by the high pressure within the capsule formed by the high concentration of poly--glutamate in the capsule matrix. Poly--glutamate is a polyanion that binds cations tightly, including the fluorescent cationic dyes acridine orange and DAPI (4',6-diamidino-2-phenylindole). We have used acridine orange and DAPI staining to localize poly--glutamate within capsules and to follow the biosynthesis of poly--glutamate during capsule formation. The results indicate that poly--glutamate biosynthesis occurs late in capsule formation after invagination of the tubule and that it is accompanied by swelling of the capsule due to increasing osmotic pressure. The matrix in all four capsule types is homogeneously filled with poly--glutamate. In vivo this poly--glutamate is complexed with monovalent cations. In addition, poly--glutamate is formed within the tubule lumen of stenoteles. We argue that this poly--glutamate is required to drive the two-step explosion process in stenotele nematocysts.

Key words: Hydra, Nematocyst, Poly--glutamate, Acridine orange, DAPI

CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    Twitter    What's this?

This article has been cited by other articles:

				A. J. Reft, J. A. Westfall, and D. G. Fautin Formation of the Apical Flaps in Nematocysts of Sea Anemones (Cnidaria: Actiniaria) Biol. Bull., August 1, 2009; 217(1): 25 - 34. [Abstract] [Full Text] [PDF]

				J. S. Hwang, H. Ohyanagi, S. Hayakawa, N. Osato, C. Nishimiya-Fujisawa, K. Ikeo, C. N. David, T. Fujisawa, and T. Gojobori The evolutionary emergence of cell type-specific genes inferred from the gene expression analysis of Hydra PNAS, September 11, 2007; 104(37): 14735 - 14740. [Abstract] [Full Text] [PDF]

				S. Ozbek, O. Pertz, M. Schwager, A. Lustig, T. Holstein, and J. Engel Structure/Function Relationships in the Minicollagen of Hydra Nematocysts J. Biol. Chem., December 13, 2002; 277(51): 49200 - 49204. [Abstract] [Full Text] [PDF]

				U. Engel, S. Oezbek, R. Engel, B. Petri, F. Lottspeich, and T. W. Holstein Nowa, a novel protein with minicollagen Cys-rich domains, is involved in nematocyst formation in Hydra J. Cell Sci., October 15, 2002; 115(20): 3923 - 3934. [Abstract] [Full Text] [PDF]