Localization of actin in the Tetrahymena basal body-cage complex

1992 ◽  
Vol 103 (3) ◽  
pp. 629-641 ◽  
Author(s):  
J.G. Hoey ◽  
R.H. Gavin

In the ciliate cytoskeleton, basal bodies are contained within separate, filamentous cages which are closely associated with basal body microtubules. We have used two polyclonal anti-actin antibodies to localize actin within the basal body-cage complex of Tetrahymena. An antiserum against a Tetrahymena oral apparatus fraction enriched for basal body proteins was produced in rabbits. Agarose-linked chicken muscle actin was used to affinity-purify anti-Tetrahymena actin antibodies from the anti-oral apparatus antiserum. Agarose-linked chicken muscle actin was used to affinity-purify anti-chicken muscle actin antibodies from a commercially available antiserum against chicken muscle actin. Both affinity-purified antibodies were monospecific for Tetrahymena actin on immunoblots containing total oral apparatus protein. The anti-actin antibodies were localized to both somatic and oral basal bodies in Tetrahymena by immunofluorescence microscopy. At the ultrastructural level with the immunogold technique, these antibodies labeled actin epitopes in four distinct regions of the basal body-cage complex: (a) basal body walls, (b) basal plate filaments, (c) proximal-end filaments and (d) cage wall filaments. In addition, the antibody labeled filament bundles that interconnect groups of basal bodies (membranelles) within the oral apparatus. Identical labeling patterns were observed with basal bodies in the isolated oral apparatus, basal bodies in the in situ oral apparatus and somatic basal bodies in situ. Quantitative analysis of gold particle distribution was used to demonstrate the specificity of the antibodies for the basal body-cage complex and to show that non-specific binding of the antibodies was negligible. Preadsorption of the antibody with muscle actin effectively eliminated the capacity of the antibody to bind to proteins on immunoblots and to basal body structures with the immunogold labeling technique. These results provide evidence for actin in the basal body-cage complex and raise the possibility of a contractile system associated with basal bodies.

1995 ◽  
Vol 108 (3) ◽  
pp. 869-881
Author(s):  
J.A. Garces ◽  
J.G. Hoey ◽  
R.H. Gavin

The basal body cage is a fibrillar chamber which surrounds each basal body in the ciliate cytoskeleton. The function of this chamber is unknown. In Tetrahymena, the cage contains actin filaments which connect the cage to triplet microtubules. In this study, we have examined the cage for the presence of myosin. Skeletal muscle myosin-II heavy and light chains were used to affinity-purify anti-MHC and anti-MLC antibodies, respectively, from an antiserum raised against Tetrahymena oral apparatus proteins. On western immunoblots of ATP-solubilized Tetrahymena proteins, the anti-MHC antibody detected a putative myosin heavy (180 kDa) chain, and the anti-MLC antibody detected a putative myosin light (18 kDa) chain. The anti-MHC antibody specifically labeled the AI zone of sarcomeres. In cosedimentation assays with an ATP-solubilized protein fraction, the 180 kDa polypeptide associated with skeletal muscle actin filaments in an ATP-dependent manner. The sedimented actin filaments appeared to be organized into bundles. Immunodepletion of the 180 kDa rendered the ATP-solubilized protein fraction ineffective in bundling actin filaments in a cosedimentation assay. ATP-solubilized Tetrahymena proteins, which included the 180 kDa polypeptide, exhibited F-actin-stimulated, Mg2+ ATPase activity and K+, EDTA ATPase activity which are characteristic of myosin ATPases. Immunodepletion of the 180 kDa polypeptide reduced the F-actin, Mg2+ ATPase activity of the ATP-solubilized protein fraction by more than 80%. Based on these various observations, we conclude that the 180 kDa polypeptide is a putative myosin heavy chain, probably a myosin-II and that the 18 kDa polypeptide is probably a myosin-II light chain. We have used the affinity-purified, anti-myosin antibodies with immunofluorescence microscopy and immunogold electron microscopy to map the location of the putative myosin heavy and light chains in Tetrahymena. Immunofluorescence microscopy showed that the anti-myosin antibodies localized to Tetrahymena somatic and oral region basal bodies. At the ultrastructural level, the anti-myosin antibodies localized to filaments in the basal body-cage complex. The labeling patterns with both anti-myosin antibodies were identical to the labeling pattern observed with an anti-actin antibody reported in a previous study. The co-localization of myosin and actin argue for a motility system within the basal body-cage complex.


Author(s):  
Joseph E. Mazurkiewicz

Immunocytochemistry is a powerful investigative approach in which one of the most exacting examples of specificity, that of the reaction of an antibody with its antigen, isused to localize tissue and cell specific molecules in situ. Following the introduction of fluorescent labeled antibodies in T950, a large number of molecules of biological interest had been studied with light microscopy, especially antigens involved in the pathogenesis of some diseases. However, with advances in electron microscopy, newer methods were needed which could reveal these reactions at the ultrastructural level. An electron dense label that could be coupled to an antibody without the loss of immunologic activity was desired.


Author(s):  
Robert Hard ◽  
Gerald Rupp ◽  
Matthew L. Withiam-Leitch ◽  
Lisa Cardamone

In a coordinated field of beating cilia, the direction of the power stroke is correlated with the orientation of basal body appendages, called basal feet. In newt lung ciliated cells, adjacent basal feet are interconnected by cold-stable microtubules (basal MTs). In the present study, we investigate the hypothesis that these basal MTs stabilize ciliary distribution and alignment. To accomplish this, newt lung primary cultures were treated with the microtubule disrupting agent, Colcemid. In newt lung cultures, cilia normally disperse in a characteristic fashion as the mucociliary epithelium migrates from the tissue explant. Four arbitrary, but progressive stages of dispersion were defined and used to monitor this redistribution process. Ciliaiy beat frequency, coordination, and dispersion were assessed for 91 hrs in untreated (control) and treated cultures. When compared to controls, cilia dispersed more rapidly and ciliary coordination decreased markedly in cultures treated with Colcemid (2 mM). Correlative LM/EM was used to assess whether these effects of Colcemid were coupled to ultrastructural changes. Living cells were defined as having coordinated or uncoordinated cilia and then were processed for transmission EM.


Author(s):  
László G. Kömüves

Light microscopic immunohistochemistry based on the principle of capillary action staining is a widely used method to localize antigens. Capillary action immunostaining, however, has not been tested or applied to detect antigens at the ultrastructural level. The aim of this work was to establish a capillary action staining method for localization of intracellular antigens, using colloidal gold probes.Post-embedding capillary action immunocytochemistry was used to detect maternal IgG in the small intestine of newborn suckling piglets. Pieces of the jejunum of newborn piglets suckled for 12 h were fixed and embedded into LR White resin. Sections on nickel grids were secured on a capillary action glass slide (100 μm wide capillary gap, Bio-Tek Solutions, Santa Barbara CA, distributed by CMS, Houston, TX) by double sided adhesive tape. Immunolabeling was performed by applying reagents over the grids using capillary action and removing reagents by blotting on filter paper. Reagents for capillary action staining were from Biomeda (Foster City, CA). The following steps were performed: 1) wet the surface of the sections with automation buffer twice, 5 min each; 2) block non-specific binding sites with tissue conditioner, 10 min; 3) apply first antibody (affinity-purified rabbit anti-porcine IgG, Sigma Chem. Co., St. Louis, MO), diluted in probe diluent, 1 hour; 4) wash with automation buffer three times, 5 min each; 5) apply gold probe (goat anti-rabbit IgG conjugated to 10 nm colloidal gold, Zymed Laboratories, South San Francisco, CA) diluted in probe diluent, 30 min; 6) wash with automation buffer three times, 5 min each; 7) post-fix with 5% glutaraldehyde in PBS for 10 min; 8) wash with PBS twice, 5 min each; 9) contrast with 1% OSO4 in PBS for 15 min; 10) wash with PBS followed by distilled water for5 min each; 11) stain with 2% uranyl acetate for 10 min; 12) stain with lead citrate for 2 min; 13) wash with distilled water three times, 1 min each. The glass slides were separated, and the grids were air-dried, then removed from the adhesive tape. The following controls were used to ensure the specificity of labeling: i) omission of the first antibody; ii) normal rabbit IgG in lieu of first antibody; iii) rabbit anti-porcine IgG absorbed with porcine IgG.


2021 ◽  
pp. 106689692110313
Author(s):  
Alexander M. Strait ◽  
Julia A. Bridge ◽  
Anthony J. Iafrate ◽  
Marilyn M. Li ◽  
Feng Xu ◽  
...  

Myofibroblastoma is a rare, benign stromal tumor with a diverse morphologic spectrum. Mammary-type myofibroblastoma (MTMF) is the extra-mammary counterpart of this neoplasm and its occurrence throughout the body has become increasingly recognized. Similar morphologic variations of MTMF have now been described which mirror those seen in the breast. We describe a case of intra-abdominal MTMF composed of short fascicles of eosinophilic spindle cells admixed with mature adipose tissue. The spindle cells stained diffusely positive for CD34, desmin, smooth muscle actin, and h-caldesmon by immunohistochemistry. Concurrent loss of RB1 (13q14) and 13q34 loci were confirmed by fluorescence in situ hybridization whereas anchored multiplex PCR and whole transcriptome sequencing did not reveal any pathognomonic fusions suggesting an alternative diagnosis. To the best of our knowledge this is the first documented case of leiomyomatous variant of MTMF.


1993 ◽  
Vol 25 (6) ◽  
pp. 421-429 ◽  
Author(s):  
A. L. Morey ◽  
D. J. P. Ferguson ◽  
K. O. Leslie ◽  
D. J. Taatjes ◽  
K. A. Fleming

1991 ◽  
Vol 100 (4) ◽  
pp. 707-715 ◽  
Author(s):  
IRM HUTTENLAUCH ◽  
ROBERT K. PECK

The membrane skeleton, or epiplasm, is part of the structurally complex ciliate cortex. It is thought to have skeletal functions concerning the spatial organization of cortical elements such as the basal bodies. Here we report the biochemical and immunological characterization of some components of the purified epiplasm of Pseudomicrothorax dubius. The epiplasm proteins consist of two quantitatively major groups of proteins, one of 76–80x103Mr, the other of 11–13x103Mr, which appear to be the principal structural elements of the epiplasm, and a series of minor components of 62–18x103Mr. Based upon lectin labeling and glycosidase treatment, some of the latter have been identified as glycoproteins. Using affinity-purified antibodies specific for individual glycoproteins or groups of glycoproteins, we were able to localize them in situ by immunoelectron microscopical methods. This in situ localization demonstrates that the glycosylated epitopes, unlike the glycoresidues of membrane proteins, are distributed throughout the entire epiplasmic layer rather than being restricted to regions adjacent to the cortical membranes. Thus, these proteins represent glycosylated, cytoskeletal elements. At least one of these glycoproteins (Mr 62x103) shows positive immunoreactivity with a monoclonal antibody (Pruss anti-IFA) recognizing most intermediate filament (IF) proteins, indicating that IF proteins might be present in protozoan cytoskeletons.


1994 ◽  
Vol 107 (2) ◽  
pp. 463-475 ◽  
Author(s):  
M.C. Azum-Gelade ◽  
J. Noaillac-Depeyre ◽  
M. Caizergues-Ferrer ◽  
N. Gas

The distribution of the U3 small nuclear RNA during the cell cycle of the CHO cell line was studied by in situ hybridization using digoxigenin-labelled oligonucleotide probes. The location of the hybrids by immunofluorescence microscopy and at the ultrastructural level was correlated with the distribution of two nucleolar proteins, nucleolin and fibrillarin. The U3 snRNA molecules persist throughout mitosis in close association with the nucleolar remnant. U3 snRNA is present in the prenucleolar bodies (PNBs) and could participate in nucleologenesis in association with several nucleolar proteins such as nucleolin and fibrillarin. The interaction of U3 snRNP with the 5′ external spacer of pre-RNA newly synthesized by active NORs is proposed to be the promoting event of nucleologenesis.


1970 ◽  
Vol 6 (3) ◽  
pp. 679-700
Author(s):  
J. WOLFE

The oral apparatus of Tetrahymena pyriformis was isolated using a non-ionic detergent to disrupt the cell membrane. The mouth consists largely of basal bodies and microfilaments. Each basal body is attached to the mouth by a basal plate which is integrated into the meshwork of microfilaments that confers upon the oral apparatus its structural integrity. Each basal body is composed of 9 triplet microtubules. Two of the 3 tubules, subfibres ‘A’ and ‘B’ are composed of filamentous rows of globules with a spacing of 4.5nm. The third tubule, subfibre ‘C’, is only one-third the length of the basal body.


1978 ◽  
Vol 31 (1) ◽  
pp. 25-35
Author(s):  
M.A. Gillott ◽  
R.E. Triemer

The ultrastructure of mitosis in Euglena gracilis was investigated. At preprophase the nucleus migrates anteriorly and associates with the basal bodies. Flagella and basal bodies replicate at preprophase. Cells retain motility throughout division. The reservoir and the prophase nucleus elongate perpendicular to the incipient cleavage furrow. One basal body pair surrounded by a ribosome-free zone is found at each of the nuclear poles. The spindle forms within the intact nuclear envelope- Polar fenestrae are absent. At metaphase, the endosome is elongated from pole to pole, and chromosomes are loosely arranged in the equatorial region. Distinct, trilayered kinetochores are present. Spindle elongates as chromosomes migrate to the poles forming a dumb-bell shaped nucleus by telophase. Daughter nuclei are formed by constriction of the nuclear envelope. Cytokinesis is accomplished by furrowing. Cell division in Euglena is compared with that of certain other algae.


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