Rodlet Cells Research Articles

Distribution and Morphology of the Rodlet Cell in Fish

A short review of the work done on the rodlet cell is presented. The morphology and distribution of rodlet cells in several species of fish, primarily marine, is described and compared with that reported by other authors, mainly in freshwater fish. The morphology in freshwater and marine fish is similar, but variations are present in different tissues in the same fish. The rodlet cell was found in a wide range of tissues in most of the fish studied. It usually occurs in epithelia, with the apex facing the lumen. The possible function of the rodlet cell is discussed. Key words: rodlet cell, fish, morphology, ultrastructure

Intranuclear Crystals in Epithelial Cells of Perca Flavescens

During microscopic examination of tissues of healthy-appearing perch caught in N.E. Minnesota lakes, it was noticed that the specimens frequently had variable numbers of epithelial cells whose nuclei contained eosinophilic inclusion bodies. These nuclear inclusions were found in a number of sites: surface epithelial cells of gill, skin and distal rectum; columnar cells of kidney collecting ducts; taste bud cells and, rarely, chloride cells of gill. In addition, the inclusions were found in rodlet cells in all of these regions, but not in rodlet or other epithelial cells of intestine. Under the electron microscope, these nuclear inclusions appear as 4-, 5-, and 6-sided paracrystals ranging in length from less than 0.5 μm to greater than 3 μm. The inclusions are usually surrounded by a narrow rim of electron-lucent nucleoplasm. Some crystals are composed of circular subunits hooked together (?) in parallel rows.

An ultrastructural study of the enigmatic "rodlet cells" in the white sucker, Catostomus commersoni (Lacépède) (Pisces: Catostomidae).

The cytology of immature and mature stages of a peculiar and widespread cell, the "rodlet cell" is described from the epithelium of the operculum and gill raker of the white sucker, Catostomus commersoni. Immature stages were observed in the intermediate and basal zones of the epithelium. They were spherical to ovoid in shape and surrounded by a limiting membrane, beneath which were numerous microfilaments arranged in parallel. The cytoplasm of immature rodlet cells contained a prominent "active" Golgi complex, peripherally arranged mitochondria, numerous free ribosomes, and an extensive network of distended cisternae of granular endoplasmic reticulum. Mature rodlet cells were usually observed along the epithelial surface. These fusiform cells were surrounded by a thick wall which contained circumferentially arranged microfilaments. A nucleus, a spherical inclusion, and a Golgi complex were observed in the basal region of the cell. The cytoplasm contained many closely packed vesicles. Numerous mitochondria were aggregated in the apical region of the cell, which terminated in three or more microvillus-like processes. While the nature and function of the rodlet cells is not elucidated, it is postulated that they are not protozoan parasites.

Some aspects of the infrastructure of the ‘Stäbchendrüscnzellen’, a peculiar cell associated with the endothelium of the bulbus arteriosus and with other fish tissues*

The fine structure of an unusual cell, the ‘Stäbchendriisenzellen’ (the so‐called foliaceous or rodlet cells of several authors), associated with the endothelium of the vascular system of marine and freshwater fishes was studied in the goldfish Carassius auratus (L.). The bulbus arteriosus was fixed with either a 6 % solution of buffered glutaraldehyde or with one part of a 3 % solution of lanthanum nitrate plus two parts of a 3 % solution of buffered glutaraldehyde and then post‐fixed in a 1.2% solution of osmium tetroxide. Electron micrographs of the vascular tissue show four cell forms which appear to be phases in the life cycle of the endothelium‐associated cell. Two of the phases are not encased and are characterized by their inclusions: in one cell these are crystalline, while in the second, they are amorphous and granular. In the other phases the cell is encased partially or completely within an apparently contractile fibrous wall surrounded by the plasmalemma. In the encased phases, the arrangement and condition of the cell organelles appears to have been changed, and in the fully‐encased phase mitochondrial activity seems to have decreased. This apparent change in the mitochondrial activity is accompanied by a thickening of the mitochondrial membrane from 48 to 109 Å. The micrographs seem to indicate that this cell in question behaves as a foreign body and, in some way, may be interacting with the epithelial tissue of the bulbus arteriosus.

Ultrastructure and Development of Rodlet Cells in Gill and Intestine of Walleyed Pike (Stizostedion vitreum)

Tissues from the gut and gill of walleyed pike, ranging in age from birth to one year, reared in tanks separate from mature fish, were examined with the electron microscope for rodlet cells. While these cells are thought to be intercellular parasites (Rhabdospora thelohani) by some investigators, the present study supports the view held by others that they are secretory cells of the fish. Mature and previously undescribed immature rodlet cells were examined.Mature rodlet cells contain a basal nucleus with a supranuclear Golgi and associated saccules and vesicles. Large club-shaped sacs, the narrow parts of which converge upon an opening in the apex of the cell, comprise much of the cytoplasm. The sacs contain a dense-staining amorphous “core” substance surrounded by less dense material.

魚類消化管上皮のPear-shaped Cell (Rodlet Cell) について

It is well known that so-called “pear-shaped cell” or “rodlet cell” is found to occur in the epithelium of the digestive tract of fishes. In the black rockfish, Sebastes inermis CUVIER, pear-shaped cells are frequently found among the columnar epithelial cells and goblet cells forming the lining epithelium of pyloric caeca (Figs. 1 and 2). Electron microscopy revealed that the cell is enclosed by a thick fibrous capsular wall (Fig. 3). Mitochondria are clustered in the apical cytoplasm. The nucleus is located at the basal end. A moderate amount of endoplasmic reticulum is scattered in the remainder of the cytoplasm as well as vesicles, vacuoles, and ribosomes. The rodlets lying parallel to the long axis of the cell are composed of three principal layers; dense central axis, moderately dense medullary part, and thin cortical layer (Fig. 3). Judging from the evidence of fine structure, it is conceivable that the pear-shaped cell is protozoan parasite, not a tissue cell. However, the taxonomic status of this peculiar parasite is uncertain.