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

This Article 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 Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by OAMI, K. Articles by NAITOH, Y. Search for Related Content PubMed Articles by OAMI, K. Articles by NAITOH, Y.

Journal of Experimental Biology 145,1-8 (1989)
Published by Company of Biologists 1989

H⁺-Dependent Contraction of the Tritonextracted Tentacle of the Dinoflagellate Noctiluca Miliaris

KAZUNORI OAMI ¹ and YUTAKA NAITOH ¹

¹ Institute of Biological Sciences, University of Tsukuba, Tsukuba 305, Japan

The intracellular conditions required for contraction in the food-gathering tentacle of a marine dinoflagellate Noctiluca miliaris were examined in the isolated tentacle, treated with Triton X-100. The tentacle flexed to its full extent when the pH of the reactivation medium was lowered to 4.0, and extended when it was raised again to its original value. Adenosine triphosphate (ATP) was not needed for the pH-dependent flexion-extension. The flexion was also produced by Ca²⁺, but in a concentration range more than a thousand times higher than the effective H⁺ concentration range for producing the flexion. It is concluded that movement of the tentacle in a live specimen of Noctiluca is controlled by membrane potential-regulated cytoplasmic pH.

Key words: Noctiluca miliaris, H⁺-dependent contraction, food-gathering tentacle, bioelectric control

Accepted on April 6, 1989