Vorticella: “A Cell For All Seasons”1

Abstract

UR studies on the peritrich ciliate, Vorticella convallaria 0 did not begin in a vacuum and much credit for our success must go to scientists who have gone before. One of those upon whom we depended most was Dr. Harold Finley and his students and colleagues who contributed much to enlighten us about Vorticella's potential as a research tool for the study of biological problems. Dr. Finley's Past Presidential Address to the Society entitled, "What have Peritrichs Taught Us" [27] in the then Journal of Protozoology gives an excellent historical exposition about peritrichs in general and Vorticella in particular. Examples of his breadth of study using peritrichs may be seen in the following selected citations: biochemistry 1291, conjugation and sexual differentiation [23, 24, 251, cytology [13], ecology [22, 301, encystment [28], growth and nutritional studies [26, 631, and taxonomy [53].Our goals in studying Vorticella convalZariu include understanding the morphogenetic transitions of the cell, understanding the mechanism of stalk formation, and elucidating the components of the contractile spasmoneme. One continuing interest has been to elucidate the mechanism that transforms V. convallaria from the feeding trophont-stage to the motile telotrochstage. We hope that by investigating this process we can develop a chemical method of synchronous telotroch formation from large populations of sessile vorticellan cells. Then, we can begin the task of deciphering the mechanics of this transitional change.We are also interested in knowing more about stalk formation. Previous work in this area (Suchard, J. S. 1979. An analysis of the morphogenic events leading to telotroch formation, settlement, and stalk development in the peritrich ciliate Zoothumnium arhusculu. Dissertation. University of Maryland, College Park, MD) [81] has shown that stalk formation is correlated with exocytosis of granules found in the aboral region of the telotroch. We are interested in extending these studies by tracing the pathway of these precursor materials into the stalk itself using stalk-specific antibodies. Last, but surely not least, we are interested in studying the spasmoneme contractile mechanism including cloning and sequencing the gene coding for the protein spasmin. This protein is believed to be a member 'Past-President's Address dedicated to the memory of Harold E. Finlay, of the centrin family of calcium-binding EF-hand proteins that includes centridcaltractin.In any pioneering study, there is a myriad of hurdles to be overcome before one can move on to solving interesting problems. Therefore, in order to carry out these studies, it was important to be able to grow Vorticella in a controlled manner and to be able to manipulate its life cycle.1. Problem #I-Catch the rabbit. There is an old saying that goes like this, "In order to make rabbit stew, one must first catch the rabbit." In this case, the rabbit is Vorticella and the stew is a medium that allows full growth of this peritrich. Our cells, used in the studies described below, ...

Inhibition of Vorticetta microstoma Stalk Formation by Wheat Germ Agglutinin

“…Vorticella has great potential as a research tool, particularly for problems related to morphogenetic transitions of the cell (Buhse 1998). WGA and ConA should be useful probes for additional studies concerning the development and function of the vorticellid stalk.…”

“…VORTICELLID trophonts are sessile ciliates that are attached to various surfaces in aqueous environments by complex contractile stalks (Barlow and Finley 1976; Buhse 1998). Vorticellid stalks are interesting because of adherence to a variety of wet surfaces and because of a unique spring‐like mechanism for high‐speed contraction (Mahadevan and Mat‐sudaira 2000; Moriyama, Hiyama, and Asai 1998).…”

“…The contractile portion of the vorticellid stalk is a filamentous organelle, the spasmoneme. The spasmoneme is bounded by three cellular membranes, an extracellular matrix, and an outer sheath (Allen 1973a, b; Buhse 1998; Wibel et al 1997). Stalk formation occurs during differentiation of a free‐swimming telotroch into a trophont.…”

“…During the initial stage of attachment, a telotroch releases the dense granules by exocytosis. The prestalk material seems to be discharged as a liquid that solidifies to form three structures, an adhesive pad, the stalk matrix, and stalk sheath (Amin and Buhse 1995; Buhse 1998; Wibel et al 1997). The stalk grows rapidly during the first hour after attachment and then continues more slowly for several hours (Vacchiano et al 1992).…”

“…Vorticella has Peat Potential as a research tool, PdcUlarlY Maciejewski, J. J., Vacchiano, E. J., McCutcheon, S. M. & Buhse, H. for problems related to morphogenetic transitions of the Cell E., Jr. 1999. Cloning and expression of a cDNA encoding a Vorticella (Buhse 1998). WGA and ConA should be useful probes for convallaria spasmin: an EF-hand calcium binding protein.…”