Light and Electron Microscopic Observations on the Heterotrich Ciliate Climacostomum virens

Abstract

SYNOPSIS. Alveolar membranes and an epiplasm exist under the cell membrane of the noncontractile heterotrich ciliate Climacostomum virens. Postciliary microtubular ribbons join at the right of each somatic kinety to form a Km fiber. Two transverse microtubular fibers occur per kinetosomal pair. A myonemal network interconnects the kinetosomal bases intrakinetally and interkinetally. Ultrastructural comparisons are made between the contractile and noncontractile heterotrichs. The buccal cortex consists of an adoral zone of membranelles, a peristomal field, a buccal tube, the apical membranelles, and a haplokinety. The kineties of the peristomal field and buccal tube are rows of paired kinetosomes, with a postciliary ribbon of microtubules arising from the posterior kinetosome of each pair, and a transverse ribbon and an oblique ribbon from the anterior kinetosome. No Km fibers exist in this region. The haplokinety is a collar of paired kinetosomes surrounding the cytostome; a postciliary microtubular ribbon descends from each kinetosomal pair into the cytostomal region. Ultrastructural details of the buccal cortex of C. virens and other heterotrichs are compared. The nemadesmata which lie under the membranelles are implicated in the body bending of C. virens. Algae endosymbiotic in the cytoplasm of C. virens are described.

Macronuclear DNA in Stentor coeruleus: a first approach to its characterization

“…Cytochemical studies have not been made but these masses are probably similar to those found in Paramecium (Ehret & Powers, 1955), and for heterotrichs in Blepharisma (Giese, 1973). S. coeruleus does not typically contain the large nucleoli found in another heterotrich, Climacostomum virens (Peck et al 1975).…”

Morphogenesis in the Heterotrich Ciliate Climacostomum virens. II. Oral Development During Regeneration1

“…A shedding procedure for the OA, employing urea, and an in vivo ingestion test for RG are presented; both provide a reproducible and well synchronized morphogenetic system for future study. The morphology, ultrastructure, division stomatogenesis, and ingestion in C. virens have been previously reported (7,12,13,23,29).…”

“…Supported by grants 3.140.77 and 3.657.80 from the Fonds National Suisse de la Recherche Scientifique. 10,000 cells were transferred to a dish (90 mm diameter; 50 mm height) containing 50 ml of Carter's medium (23) and maintained at 26°C. Ciliates were fed daily by giving them enough Chlorogonium to fill each cell without overfeeding (overfeeding results in an abnormal, "bloated" appearance).…”

“…In the very strong shedding type (Figs. 23,24), all the external features of tee OA are removed, and a short segment of the buccal tube may or may not remain; this extreme situation occurs in only -0.5% of the cells. Finally, an average of 2.89/0 of the cells do not shed their OA.…”

“…3,8, 13, 17,18 and cell measurements are reported in Table 11. Buccal terminology is the same as employed previously (7, 23), except that the "haplokinety" (23) or "double row of kinetosomes" (7) is here referred to as the paroral kinety (see Discussion).…”