RRC ID 29669
著者 Khan SM, Arikawa M, Omura G, Suetomo Y, Kakuta S, Suzaki T.
タイトル Axopodial contraction in the heliozoon Raphidiophrys contractilis requires extracellular Ca2+.
ジャーナル Zoolog Sci
Abstract Axopodial contraction of the centrohelid heliozoon Raphidiophrys contractilis was induced by mechanical or electrical stimulation. For inducing contraction, extracellular Ca(2+) was required. The threshold level of extracellular Ca(2+) was between 10(-6)-10(-7) M. The speed of axopodial contraction was faster than 3.0 mm/sec. Re-elongation of axopodia started just after contraction, and its initial velocity was approximately 0.30 microm/sec. Electron microscopic observations were carried out using an improved fixative that contained 1 mg/ml ruthenium red and 15 microM Taxol. This fixative prevented artificial retraction of axopodia and resulted in better fixation. A bundle of hexagonally-arranged microtubules was observed in each axopodium, but no other filamentous structures were detected, suggesting that the contractile machinery of axopodia in R. contractilis may be different from that in actinophryid heliozoons in which Ca(2+)-dependent contractile filaments are employed for contraction.
巻・号 20(11)
ページ 1367-72
公開日 2003-11-1
DOI 10.2108/zsj.20.1367
PMID 14624035
MeSH Animals Calcium / physiology* Cations, Divalent Electric Stimulation Eukaryota / cytology* Eukaryota / physiology Histological Techniques Japan Microscopy, Electron Movement / physiology* Pseudopodia / physiology* Pseudopodia / ultrastructure
IF 0.843
引用数 3
WOS 分野 ZOOLOGY
リソース情報
藻類 NIES-2498