Paramecium species, especially P. tetraurelia and caudatum, are model organisms for modern research into the form and function of cilia. In this review, we focus on the ciliary ion channels and other transmembrane proteins that control the beat frequency and wave form of the cilium by controlling the signaling within the cilium. We put these discussions in the context of the advantages that Par...

in many kinds of eukaryote are controlled by changes in intracellular Ca2+ concentration. Ciliary movement in Paramecium comprises two kinds of ciliary strokes, the effective stroke and the recovery stroke, and shows metachronal coordination (Machemer, 1972). When Paramecia meet an obstacle, their cilia reverse the direction of their beat, allowing the organism to swim backwards (Jennings, 1906...

M A T I N G type determination and inheritance in Paramecium caudatum has been reported only for syngen 12 (HIWATASHI 1958). Inheritance was usually synclonal, i.e. the two clones derived from the two members of a conjugating pair are identical in mating type expression, indicating direct genic control of mating type. However the breeding analysis was incomplete and some of the observations, as...

Bracken ferns (genus Pteridium) represent an ancient species complex with a natural worldwide distribution. Pteridium has historically been treated as comprising a single species, but recent treatments have recognized several related species. Phenotypic plasticity, geographically structured morphological variation, and geographically biased sampling have all contributed to taxonomic confusion i...

Membrane excitation was the basis for backward swimming of Paramecium facing stimulus. According to standard genetic tests, inexcitable mutants fell into three complementation groups for both Paramecium tetraurelia (pwA, pwB, and pwC) and Paramecium caudatum (cnrA, cnrB, and cnrC). Cytoplasm from a wild type transferred to a mutant through microinjection restored the excitability. Transfusions ...