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

1975 ◽  
Vol 53 (11) ◽  
pp. 1483-1494 ◽  
Author(s):  
Sherwin S. Desser ◽  
Robert Lester

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.

1989 ◽  
Vol 109 (6) ◽  
pp. 2817-2832 ◽  
Author(s):  
R Bacallao ◽  
C Antony ◽  
C Dotti ◽  
E Karsenti ◽  
E H Stelzer ◽  
...  

Studies of the developing trophectoderm in the mouse embryo have shown that extensive cellular remodeling occurs during epithelial formation. In this investigation, confocal immunofluorescence microscopy is used to examine the three-dimensional changes in cellular architecture that take place during the polarization of a terminally differentiated epithelial cell line. Madin-Darby canine kidney cells were plated at a low density on permeable filter supports. Antibodies that specifically recognize components of the tight junction, adherens junction, microtubules, centrosomes, and the Golgi complex were used to study the spatial remodeling of the cytoarchitecture during the formation of the polarized cell layer. The immunofluorescence data were correlated with establishment of functional tight junctions as measured by transepithelial resistance and back-exchange of the cell surface, labeled with metabolites of the fluorescent lipid analogue N-(7-[4-nitrobenzo-2-oxa-1,3-diazole]) aminocaproyl sphingosine. 1 d after plating, single cells had microtubules, radiating from a broad region, that contained the centrosomes and the Golgi complex. 2 d after plating, the cells had grown to confluence and had formed functional tight junctions close to the substratum. The centrioles had split and no longer organized the microtubules which were running above and below the nucleus. The Golgi complex had spread around the nucleus. By the fifth day after plating, the final polarized state had been achieved. The junctional complex had moved greater than 10 microns upward from its basal location. The centrioles were together below the apical membrane, and the Golgi complex formed a ribbon-like convoluted structure located in the apical region above the nucleus. The microtubules were organized in an apical web and in longitudinal microtubule bundles in the apical-basal axis of the columnar cell. The longitudinal microtubules were arranged with their minus ends spread over the apical region of the cell and their plus ends toward the basal region. These findings show that there is an extensive remodeling of epithelial cytoarchitecture after formation of cell-cell contacts. Reorganization of the microtubule network results in functional polarization of the cytoplasm.


1986 ◽  
Vol 64 (4) ◽  
pp. 805-813 ◽  
Author(s):  
D. L. Barber ◽  
J. E. Mills Westermann

Rodlet cells, enigmatic, variably present components of several teleost epithelia, have been regarded as normal cells of unknown function or parasites of unknown phylogeny. The present study examines rodlet cells in the northern creek chub, Semotilus atromaculatus, and the white sucker, Catostomus commersoni. In light microscopic histochemistry, rodlet cores give "RNA-type" reactions to acridine orange and methyl green – pyronin procedures, but in electon microscopy, application of the nuclease–gold procedure shows that rodlets contain DNA in a helical distribution at the core boundary, but not RNA. Rodlet cores also are labeled by S1 nuclease – gold, an enzyme that is specific for single-stranded DNA. We have concluded that DNA, and only DNA, is found in the rodlet, and that it occurs in a conformation not normally seen in the eukaryote nucleus. In fact, the rodlet with its DNA resembles no known eukaryote, prokaryote, or virus. Discussion includes the possibility that the rodlet core may be a natural example of DNA containing left-handed sequences (Z-DNA). Since the nucleus of the rodlet cell contains the same amount of DNA as nuclei of teleost cells, the cell itself is concluded to be of teleost origin, and the rodlets are proposed to be invasive structures of unknown phylogeny which convert the metabolism of the teleost cell to rodlet production.


2010 ◽  
Vol 45 (2) ◽  
pp. 187-200 ◽  
Author(s):  
Joanne L. Parrott ◽  
L. Mark Hewitt ◽  
Tibor G. Kovacs ◽  
Deborah L. MacLatchy ◽  
Pierre H. Martel ◽  
...  

Abstract To evaluate currently available bioassays for their use in investigating the causes of pulp and paper mill effluent effects on fish reproduction, the responses of wild white sucker (Catostomus commersoni) collected from the receiving environment at the bleached kraft mill at La Tuque, Quebec, were compared with responses of fathead minnow (Pimephales promelas) exposed to effluent in a laboratory lifecycle test. White sucker collected at effluent exposed sites had increased liver size but none of the reproductive effects that had been documented in earlier field studies at this site. Exposure to 1, 3, 10, 30, and 100% bleached kraft mill effluent (BKME) in the lab led to significantly decreased length, but increased weight and liver size in male fathead minnow. Female length was also decreased and liver size was increased at high effluent exposures. Most effluent concentrations (1 to 30%) significantly increased egg production compared with controls. The fathead minnow lifecycle assay mirrored the effects seen in wild fish captured downstream of the BKME discharge. These results will be used to select short-term fish tests for investigating the causes of and solutions to the effects of mill effluents on fish reproduction.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Kazuki Motomura ◽  
Hidenori Takeuchi ◽  
Michitaka Notaguchi ◽  
Haruna Tsuchi ◽  
Atsushi Takeda ◽  
...  

AbstractDuring the double fertilization process, pollen tubes deliver two sperm cells to an ovule containing the female gametes. In the pollen tube, the vegetative nucleus and sperm cells move together to the apical region where the vegetative nucleus is thought to play a crucial role in controlling the direction and growth of the pollen tube. Here, we report the generation of pollen tubes in Arabidopsis thaliana whose vegetative nucleus and sperm cells are isolated and sealed by callose plugs in the basal region due to apical transport defects induced by mutations in the WPP domain-interacting tail-anchored proteins (WITs) and sperm cell-specific expression of a dominant mutant of the CALLOSE SYNTHASE 3 protein. Through pollen-tube guidance assays, we show that the physiologically anuclear mutant pollen tubes maintain the ability to grow and enter ovules. Our findings provide insight into the sperm cell delivery mechanism and illustrate the independence of the tip-localized vegetative nucleus from directional growth control of the pollen tube.


1995 ◽  
Vol 52 (3) ◽  
pp. 464-469 ◽  
Author(s):  
Todd M. Koel ◽  
John J. Peterka

Laboratory-based bioassays were conducted to determine concentrations of sodium-sulfate type salinities that limit the hatching success of several fish species. Survival to hatching (SH) was significantly lower (P < 0.05) in sodium-sulfate type waters from Devils Lake, North Dakota, of ≥ 2400 mg/L total dissolved solids (TDS) than in fresh water of 200 mg/L. In waters of 200, 1150, 2400, 4250, and 6350 mg/L TDS, walleye (Stizostedion vitreum) SH was 41, 38, 7, 1, and 0%; northern pike (Esox lucius) SH was 92, 68, 33, 2, and 0%; yellow perch (Perca flavescens) SH was 88, 70, 73, 0, and 0%; white sucker (Catostomus commersoni) SH was 87, 95, 66, 0, and 0%; common carp (Cyprinus carpio) SH was 71, 69, 49, 63, and 25%.


1990 ◽  
Vol 47 (1) ◽  
pp. 41-48 ◽  
Author(s):  
Molly O. Ahlgren

The ash-free dry mass (AFDM) of detritus, invertebrates, and algae in the diet of juvenile white sucker (Catostomus commersoni) was determined by quantitative microscopy. Fish were collected from a northern Michigan pond from January through October 1986 and their seasonal diet was compared with benthc invertebrate abundance. The quantity of detritus in sucker foreguts was inversely related to benthic microcrustacean densities. In July, microcrustacean densities were high and they comprised 95% of the AFDM in foregut contents. By October, microcrustacean densities had declined to 13% of their maximum density and detritus comprised over 90% of the sucker's diet AFDM. In laboratory aquaria, sucker that were fed detritus mixed with four different densities of Artemia ingested significantly more detritus from diets that provided lower Artemia densities. In the presence of high Artemia densities, sucker completely rejected detritus and ingested only Artemia, The fact that juvenile sucker can separate detritus from invertebrates that they swallow demonstrates that detritus is not ingested incidentally. Both laboratory and field data support the hypothesis that detritus is ingested intentionally when preferred invertebrate prey are scarce.


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