Evidence for the presence of DNA at basal body sites in Tetrahymena pyriformis

1965 ◽  
Vol 162 (989) ◽  
pp. 473-491 ◽  
Keyword(s):  
Cell Division ◽  
Basal Body ◽  
Mitotic Cycle ◽  
Tritiated Thymidine ◽  
Tetrahymena Pyriformis ◽  
Cell Cortex ◽  
Basal Bodies ◽  
Temperature Shock ◽  
Large Numbers ◽  
Order Of Magnitude

The reasons that have led to a search for DNA in the basal body of Tetrahymena pyriformis are twofold: the well-known property of proliferation of this organelle and the possibility that basal body DNA might be involved in its morphogenesis. After a brief review of earlier work the methods employed in this paper are described. To ensure large numbers of cells in a particular state of development organisms were grown in synchronized culture. Animals required for autoradiographic studies were appropriately treated with tritiated thymidine. All investigations were made on the cell cortex or 'ghost’ in order to avoid confusion from cell contents. In addition to autoradiography of ghosts, tests were made with acridine orange in the fluorescence microscope. It is concluded from fluorescence tests that basal bodies of T. pyriformis strain S contain DNA . This DNA is not detectable for the first 2h of the temperature-shock cycle, but is detect­able thereafter until cell division. The presence of DNA is confirmed by the autoradiography experiments. The amount of DNA per basal body is estimated very roughly in order of magnitude as 2 × 10 -16 g. The origin of basal body DNA is discussed and the possibilities and consequences of the existence of DNA in the homologous centriole are examined in terms of the mitotic cycle, the amoeba-flagellate transformation in Naegleria , and artificial parthenogenesis. The paper concludes with a brief discussion of the genetic implications of basal body DNA .

Structural Analysis of Basal Bodies of The Isolated Oral Apparatus of Tetrahymena Pyriformis

1970 ◽  
Vol 6 (3) ◽  
pp. 679-700
Author(s):  
J. WOLFE
Keyword(s):  
Structural Analysis ◽  
Cell Membrane ◽  
Basal Body ◽  
Structural Integrity ◽  
Tetrahymena Pyriformis ◽  
Basal Plate ◽  
Basal Bodies ◽  
The Third ◽  
Ionic Detergent

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.

scholarly journals The ultrastructure of cell division in Euglena gracilis

1978 ◽  
Vol 31 (1) ◽  
pp. 25-35
Author(s):  
M.A. Gillott ◽  
R.E. Triemer
Keyword(s):  
Cell Division ◽  
Nuclear Envelope ◽  
Basal Body ◽  
Euglena Gracilis ◽  
Equatorial Region ◽  
Basal Bodies ◽  
Cleavage Furrow ◽  
Free Zone ◽  
Prophase Nucleus

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.

The cell division cycle of Trypanosoma brucei brucei : timing of event markers and cytoskeletal modulations

1989 ◽  
Vol 323 (1218) ◽  
pp. 573-588 ◽  
Keyword(s):  
Cell Cycle ◽  
Cell Division ◽  
Trypanosoma Brucei ◽  
Basal Body ◽  
Single Copy ◽  
Cell Division Cycle ◽  
Basal Bodies ◽  
Division Plane ◽  
Transmission Electron ◽  
Single Nucleus

We have analysed the timing and order of events occurring within the cell division cycle of Trypanosoma brucei . Cells in the earliest stages of the cell cycle possess a single copy of three major organelles: the nucleus, the kinetoplast and the flagellum. The first indication of progress through the cell cycle is the elongation of the pro-basal body lying adjacent to the mature basal body subtending the flagellum. This newly elongated basal body occupies a posterior position within the cell when it initiates growth of the new daughter flagellum. Genesis of two new pro-basal bodies occurs only after growth of the new daughter flagellum has been initiated. Extension of the new flagellum, together with the paraflagellar rod, then continues throughout a major portion of the cell cycle. During this period of flagellum elongation, kinetoplast division occurs and the two kinetoplasts, together with the two flagellar basal bodies, then move apart within the cell. Mitosis is then initiated and a complex pattern of organelle positions is achieved whereby a division plane runs longitudinally through the cell such that each daughter ultimately receives a single nucleus, kinetoplast and flagellum. These events have been described from observations of whole cytoskeletons by transmission electron microscopy together with detection of particular organelles by fluorescence microscopy. The order and timing of events within the cell cycle has been derived from analyses of the proportion of a given cell type occurring within an exponentially growing culture.

scholarly journals THE NUCLEIC ACIDS OF BASAL BODIES ISOLATED FROM TETRAHYMENA PYRIFORMIS

1965 ◽  
Vol 25 (2) ◽  
pp. 217-228 ◽  
Author(s):  
Eugene J. Hoffman
Keyword(s):  
Electron Microscope ◽  
Nucleic Acids ◽  
Basal Body ◽  
Tetrahymena Pyriformis ◽  
Isolation Procedure ◽  
Basal Bodies ◽  
Phenol Extraction ◽  
Body Self

Pellicular fragments were isolated from ethanol-fixed cells of the holotrichous ciliate Tetrahymena pyriformis by the action of digitonin. The isolated pellicles were further fragmented and the basal bodies of the cilia isolated from them by three methods. The preparations, examined in the electron microscope as embedded sections or negatively stained samples, consisted mainly of somewhat deformed pellicular material, the bulk of which was basal body. DNA was determined by the diphenylamine method and by reaction with DNase, and RNA, by the orcinol method. Nucleic acids were isolated by phenol extraction and analyzed spectrophotometrically and by reaction with RNase. The assays indicated 1.2 to 2.6 per cent RNA, similar to previously published work, but only 0.0 to 1.0 per cent DNA, near enough the sensitivity limits to render the presence of DNA in the preparations uncertain. Although the isolation procedure removed nuclear contents and ribosomes, the nucleic acids could still be a residual contaminant bound to the pellicle during the isolation. Hypotheses of basal body self-duplication, moreover, can be constructed both with and without nucleic acids.

scholarly journals THE MORPHOGENESIS OF BASAL BODIES AND ACCESSORY STRUCTURES OF THE CORTEX OF THE CILIATED PROTOZOAN TETRAHYMENA PYRIFORMIS

1969 ◽  
Vol 40 (3) ◽  
pp. 716-733 ◽  
Author(s):  
Richard D. Allen
Keyword(s):  
Basal Body ◽  
Tetrahymena Pyriformis ◽  
Basal Bodies ◽  
Proximal Surface ◽  
Body Development ◽  
Transmission Electron ◽  
Short Cylinder ◽  
Dividing Cells ◽  
Constant Distance ◽  
Single Tubules

Dividing cells of Tetrahymena pyriformis were observed by transmission electron microscopy for signs of morphogenesis of cortical structures. The earliest stage of basal body development observed was of a short cylinder of nine single tubules connected by an internal cartwheel structure. This is set perpendicular to the mature basal body at its anterior proximal surface under the transverse microtubules and next to the basal microtubules. Sequential stages show that the single tubules become triplet tubules and that the "probasal bodies" then elongate and tilt toward the organism's surface while maintaining a constant distance of 75–100 mµ with the "parent." The new basal body after it is fully extended contacts the pellicle, and then assumes a parallel orientation with and moves anterior to the parent basal body. The electron-opaque core in the lumen of the basal body and accessory structures around its outer proximal surface appear after the developing basal body has elongated. These accessory structures associating with their counterparts from other basal bodies and with the longitudinal microtubules may play a role in the final positioning of basal bodies and thus in the maintenance of cortical patterns. Observations on a second sequence of basal body formation suggest that the oral anlage arises by multiple duplication of somatic basal bodies.

scholarly journals An analogue-sensitive approach identifies basal body rotation and flagellum attachment zone elongation as key functions of PLK in Trypanosoma brucei

2013 ◽  
Vol 24 (9) ◽  
pp. 1321-1333 ◽  
Author(s):  
Ana Lozano-Núñez ◽  
Kyojiro N. Ikeda ◽  
Thomas Sauer ◽  
Christopher L. de Graffenried
Keyword(s):  
Cell Cycle ◽  
Cell Division ◽  
Rna Interference ◽  
Cell Surface ◽  
Trypanosoma Brucei ◽  
Basal Body ◽  
Basal Bodies ◽  
Body Rotation ◽  
The Many ◽  
Attachment Zone

Polo-like kinases are important regulators of cell division, playing diverse roles in mitosis and cytoskeletal inheritance. In the parasite Trypanosoma brucei, the single PLK homologue TbPLK is necessary for the assembly of a series of essential organelles that position and adhere the flagellum to the cell surface. Previous work relied on RNA interference or inhibitors of undefined specificity to inhibit TbPLK, both of which have significant experimental limitations. Here we use an analogue-sensitive approach to selectively and acutely inhibit TbPLK. T. brucei cells expressing only analogue-sensitive TbPLK (TbPLKas) grow normally, but upon treatment with inhibitor develop defects in flagellar attachment and cytokinesis. TbPLK cannot migrate effectively when inhibited and remains trapped in the posterior of the cell throughout the cell cycle. Using synchronized cells, we show that active TbPLK is a direct requirement for the assembly and extension of the flagellum attachment zone, which adheres the flagellum to the cell surface, and for the rotation of the duplicated basal bodies, which positions the new flagellum so that it can extend without impinging on the old flagellum. This approach should be applicable to the many kinases found in the T. brucei genome that lack an ascribed function.

scholarly journals PARTIAL PURIFICATION AND PHOSPHOTUNGSTATE SOLUBILIZATION OF BASAL BODIES AND KINETODESMAL FIBERS FROM TETRAHYMENA PYRIFORMIS

1973 ◽  
Vol 57 (3) ◽  
pp. 601-612 ◽  
Author(s):  
Robert W. Rubin ◽  
William P. Cunningham
Keyword(s):  
Basal Body ◽  
Gel Electrophoresis ◽  
Sucrose Gradient ◽  
Gradient Centrifugation ◽  
Sodium Dodecyl ◽  
Tetrahymena Pyriformis ◽  
Partial Purification ◽  
Basal Bodies ◽  
Thin Sectioning ◽  
Triton X

Previously devised methods for the isolation of basal bodies from ciliate protozoans were found to be inadequate for chemical analysis. We have modified and expanded these procedures and developed a method which gives preparations containing mainly basal bodies and kinetodesmal fibers. This procedure involved fixation of cells in 30% ETOH followed by digitonin or Triton X-100 solubilization and homogenization with a Brinkmann Polytron. This is followed by sucrose gradient centrifugation. Negative staining and thin sectioning revealed these preparations to be substantially more pure than those of previous workers. It was also found that neutralized phosphotungstate (PTA) solubilized many of the components present in fixed Tetrahymena. Neutralized 1.0% PTA solubilized axonemes, cortical, axonemal, and basal body microtubules as well as kinetodesmal fibers. These results have been confirmed by both electron microscope observations and gel electrophoresis of 100,000 g supernatants of the PTA extracts. A solution of 0.1% PTA did not affect the fibers but did solubilize basal bodies. Running 1.0% PTA extracts from our basal body fractions on sodium dodecyl sulfate (SDS) polyacrylamide gels allowed us to tentatively identify the peptides of basal bodies and kinetodesmal fibers. The latter structures appear to consist of a single 21,000 mol wt peptide. These results also suggest that great caution should be taken in interpreting PTA images, especially of microtubules and axonemes.

Does the oral apparatus of the ciliate Stentor inhibit oral development by release of a diffusible substance?

Development ◽  
1985 ◽  
Vol 87 (1) ◽  
pp. 241-247
Author(s):  
Nöel De Terra
Keyword(s):  
Cell Division ◽  
Cell Surface ◽  
Basal Body ◽  
Basal Bodies ◽  
Glass Needle ◽  
Oral Development

In the ciliate Stentor, many thousands of basal bodies assemble on the ventral cell surface to form a new oral apparatus during cell division, regeneration and reorganization (oral replacement during interphase). During interphase, oral development is normally inhibited by the presence of the anteriorly placed oral apparatus. A glass needle was used to cut the oral apparatus of interphase stentors in two so that the parts remained intact but separate at the anterior end of the cell. These cells initiated basal body assembly and oral development, usually within 8 h. Basal body assembly can therefore result from disconnection of fibrous structures within the oral apparatus but is unlikely to be regulated by an inhibitor diffusing from it.

A localized region of basal body proliferation in growing cells of Dileptus visscheri (ciliata, gymnostomate)

1976 ◽  
Vol 20 (1) ◽  
pp. 115-133
Author(s):  
J. Kink
Keyword(s):  
Cell Size ◽  
Basal Body ◽  
Growth Zone ◽  
The Body ◽  
Basal Bodies ◽  
Large Numbers

In the ciliate Dileptus organisms are completely organized at the time of excystation. They grow intensively, increasing in volume several times, before they reach the trophic cell size. The growth includes both the somatic part of the body as well as the oral parts, consisting of the cytostomal field and the ventral band of the proboscis. From the time of excystation, during the growth of the cell, the oral apparatus is able to capture and ingest food. Growth of an oral apparatus while functioning has not previously been reported in cilates. The proliferation of new oral kinetosomes in the growing oral apparatus occurs only in the cytostomal field. There is no proliferation of ciliature in the oral kineties of the growing proboscis. In those regions of the somatic kineties bordering the cytostomal field an extensive proliferation of somatic ciliature takes place. The zone of proliferation common to the oral and somatic ciliature supplies new kinetosomes for the elongating proboscis, the growing oral apparatus and the growth of the rest of the body. The mode of proliferation of the oral kinetosomes differs from that of the somatic kinetosomes. The oral kinetosomes form randomly in large numbers, appearing similar to an anarchic field such as is found in other ciliates. The somatic kinetosomes always arise singly and in a defined position in relation to the mature kinetosome. The proliferation of basal bodies in a defined area in Dileptus suggests the existence of a growth zone localized around the cytostomal field.

scholarly journals Sas4 links basal bodies to cell division via Hippo signaling

2020 ◽  
Vol 219 (8) ◽  
Author(s):  
Marisa D. Ruehle ◽  
Alexander J. Stemm-Wolf ◽  
Chad G. Pearson
Keyword(s):  
Cell Division ◽  
Signaling Pathway ◽  
Cortical Microtubule ◽  
Cell Cortex ◽  
Basal Bodies ◽  
Hippo Signaling ◽  
Microtubule Organization ◽  
Hippo Signaling Pathway ◽  
Daughter Cells ◽  
Striated Fiber

Basal bodies (BBs) are macromolecular complexes required for the formation and cortical positioning of cilia. Both BB assembly and DNA replication are tightly coordinated with the cell cycle to ensure their accurate segregation and propagation to daughter cells, but the mechanisms ensuring coordination are unclear. The Tetrahymena Sas4/CPAP protein is enriched at assembling BBs, localizing to the core BB structure and to the base of BB-appendage microtubules and striated fiber. Sas4 is necessary for BB assembly and cortical microtubule organization, and Sas4 loss disrupts cell division furrow positioning and DNA segregation. The Hippo signaling pathway is known to regulate cell division furrow position, and Hippo molecules localize to BBs and BB-appendages. We find that Sas4 loss disrupts localization of the Hippo activator, Mob1, suggesting that Sas4 mediates Hippo activity by promoting scaffolds for Mob1 localization to the cell cortex. Thus, Sas4 links BBs with an ancient signaling pathway known to promote the accurate and symmetric segregation of the genome.

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