Ref ID : 4139
Maruyama Tadashi; Ionic Control of the Longitudinal Flagellum in Ceratium tripos (Dinoflagellida). J.Protozool. 32(1):106-110, 1985
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In order to answer the question of how two dissimilar flagellar motions, retraction and undulation, of the longitudinal flagellum in Ceratium tripos are regulated, the effects of cationic milieu, calcium ionophore, calcium channel blockers and some anesthetics on the motion of the longitudinal flagellum were studied. The flagellum retracted and was installed in the sulcus in high K+, high Ca2+, low Na+ -ASW (artificial sea water), and low Mg2+ -ASW. Although Ca2+ ionophore X537A induced the retraction, it also induced disintegration of the flagellum. The Ca2+ channel blocker, La3+, prevented the retraction effectively in high K+ -ASW and in low Mg2+ -ASW but did not affect it in low Na+ -ASW or in high Ca2+ -ASW. Ruthenium red (RR), on the other hand, prevented the retraction in high Ca2+ -ASW, low Na+ -ASW, and low Mg2+ -ASW but did not suppress the retraction induced in high K+ -ASW. The organic Ca2+ antagonist, verapamil, or the local anesthetics, dibucaine and paraveline, did not prevent the retraction effectively in any ASW. These data suggest that the flagellum retracts when external Ca2+ enters into the flagellum. The dissimilar actions of La3+ and RR suggest that there may be two different sites for Ca2+ influx which have different affinity for La3+ or RR.