. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. primary loci. FIGURE 2. (Left) Diagram of base cell of urn cell complex, viewed from exterior surface and in profile: A. R cells in center of non-ciliated membrane; muco-ciliated rim (mcr), cilia not drawn; B, profile, secretory granules indicated by black dots; C, position of hypersecretory loci in central membrane; D, profile. Inset: relationships of vesicle (v) and base cell (b) with attached R cells. FIGURE 3. (Right) Diagram of interrelations of R cells and actively secreting loci, urn cell complex swimming forward (arr
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. primary loci. FIGURE 2. (Left) Diagram of base cell of urn cell complex, viewed from exterior surface and in profile: A. R cells in center of non-ciliated membrane; muco-ciliated rim (mcr), cilia not drawn; B, profile, secretory granules indicated by black dots; C, position of hypersecretory loci in central membrane; D, profile. Inset: relationships of vesicle (v) and base cell (b) with attached R cells. FIGURE 3. (Right) Diagram of interrelations of R cells and actively secreting loci, urn cell complex swimming forward (arrow on vesicle cell) while secreting tail emerges (arrows) pull- ing R cells with it for varying distances. Inset: relationship of vesicle cell (v), base cell (b), and R cells, shown as though junctional complexes were removed. result of bleeding. When these adherent cells are removed by centrifugation at 12,000 rpm for 1 min, the cluster of R cells and tags of the secretions are revealed (Fig. 4). From 80 to 100% of active urn cell complexes from freshly bled healthy S. nndus have clusters of 4—7 adherent R cells. Neutral red staining of urn cell complexes in individual suspensions over time has shown that beginning late in the first week and continuing for the subsequent 3-4 weeks, R cells gradually detach from the base cells of individual urn cell com- plexes (Table I). During this gradual in zntro loss of R cells, the tails of mucus induced in the free-flowing locus system change visibly, generally becoming longer and slimmer with time. In about 5% of suspensions, the R cells persist, and fore- shortened tails predominate for the life of the suspension. Thus the presence of the full complement of R cells evidently has some control over the quality of free- flowing secretions in vitro. Whether R cells may be replaced in vivo is not known. The large packages of granules in R cells stain brilliantly with neutral red, so that it is easy to follow the behavior of R cells as the
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Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
