Temperature-sensitive mutations affecting cortical morphogenesis and cell division in Paramecium tetraurelia

1982 ◽  
Vol 60 (10) ◽  
pp. 2296-2308 ◽  
Author(s):  
Donald Jones ◽  
James D. Berger
Keyword(s):  
Cell Division ◽  
Cell Surface ◽  
Posterior Part ◽  
Gene Mutations ◽  
Temperature Sensitive ◽  
Basal Bodies ◽  
Paramecium Tetraurelia ◽  
Fission Process ◽  
Daughter Cells ◽  
Recessive Genes

Nine temperature-sensitive gene mutations affecting cellular morphogenesis were analysed and shown to be single recessive genes. Their phenotypes fall into three classes: small mutants (sm) which interfere with cell surface and basal body proliferation to produce short cells; defective fission zone mutants (dfz) which do not form a complete fission zone during cell division; and defective constriction mutants (dc) which form a normal fission zone, but do not constrict properly. In sm2 cells there is a reduction in the number of basal bodies and in the amount of cell surface produced preceding fission. This results in the production of truncated daughter cells in which most of the normal structures of either the anterior or posterior part of the cell are highly reduced or missing. Production of basal bodies in gullet primordia is also abnormal. The dfz mutants act early in the fission process to block the formation of the fission zone which precedes the formation of the fission furrow. The dc mutations act later in the fission process and lead to failure of daughter cell separation. One mutant, dc3, also shows slightly reduced proliferation of cell surface. This defect occurs prior to fission.

Stomatogenesis in Paramecium tetraurelia: genetics and phenotypes of mutants affecting the development of the oral apparatus

1987 ◽  
Vol 65 (9) ◽  
pp. 2177-2187 ◽  
Author(s):  
Lai-Wa Tam ◽  
Stephen F. Ng
Keyword(s):  
Cell Division ◽  
Ultraviolet Irradiation ◽  
Buccal Cavity ◽  
The Other ◽  
Temperature Sensitive ◽  
Paramecium Tetraurelia ◽  
Single Mutant ◽  
Temperature Sensitive Mutants ◽  
Recessive Genes ◽  
Acting In Concert

Seven temperature-sensitive mutants of Paramecium tetraurelia, in which the development of the oral apparatus was affected, were recovered from mutagenesis with N-methyl-N′-nitro-N-nitrosoguanidine and ultraviolet irradiation and analysed. Five of them (short-1, buccalless-1, crook-1, monster-1, monster-2) were shown to possess single mutant recessive genes (designated sh1, bu1, cr1, mo1, and mo2, respectively). The other two, short-2 and short-3, were probably of the same mutagenic origin, which involved two linked recessive loci acting in concert. The short mutants are characterized by reduction in the length of the buccal cavity and oral membranelles and disruption of the organization of the membranelles. The crook mutant shows extra curvature and lengthening of the oral membranelles. The buccalless mutant exhibits loss of the buccal cavity, in addition to the absence, shortening, or disruption of the organization of oral membranelles. The monsters develop abnormal oral apparatuses and abnormalities in cell division giving rise to monstrous cells. All of these mutations are pleiotropic in expression. While the genes for short-1 and crook-1 affect stomatogenesis in the asexual and sexual cycles to similar extents, the other five mutants exhibit defects only in asexual stomatogenesis. The developmental interests of these mutants are discussed.

Test for temporal or spatial restrictions in gene product function during the cell division cycle

1983 ◽  
Vol 3 (7) ◽  
pp. 1255-1265
Author(s):  
S K Dutcher ◽  
L H Hartwell
Keyword(s):  
Cell Division ◽  
Gene Product ◽  
Gene Mutations ◽  
Cell Division Cycle ◽  
Temperature Sensitive ◽  
Restrictive Temperature ◽  
Product Function ◽  
Complete Cell ◽  
Relationship Of ◽  
Gene Product Function

The ability of a functional gene to complement a nonfunctional gene may depend upon the intracellular relationship of the two genes. If so, the function of the gene product in question must be limited in time or in space. CDC (cell division cycle) gene products of Saccharomyces cerevisiae control discrete steps in cell division; therefore, they constitute reasonable candidates for genes that function with temporal or spatial restrictions. In an attempt to reveal such restrictions, we compared the ability of a CDC gene to complement a temperature-sensitive cdc gene in diploids where the genes are located within the same nucleus to complementation in heterokaryons where the genes are located in different nuclei. In CDC X cdc matings, complementation was monitored in rare heterokaryons by assaying the production of cdc haploid progeny (cytoductants) at the restrictive temperature. The production of cdc cytoductants indicates that the cdc nucleus was able to complete cell division at the restrictive temperature and implies that the CDC gene product was provided by the other nucleus or by cytoplasm in the heterokaryon. Cytoductants from cdc28 or cdc37 crosses were not efficiently produced, suggesting that these two genes are restricted spatially or temporally in their function. We found that of the cdc mutants tested 33 were complemented; cdc cytoductants were recovered at least as frequently as CDC cytoductants. A particularly interesting example was provided by the CDC4 gene. Mutations in CDC4 were found previously to produce a defect in both cell division and karyogamy. Surprisingly, the cell division defect of cdc4 nuclei is complemented by CDC4 nuclei in a heterokaryon, whereas the karyogamy defect is not.

Relative daughter cell volume and position of the division furrow in Tetrahymena

1983 ◽  
Vol 61 (1) ◽  
pp. 273-287
Author(s):  
K.K. Hjelm
Keyword(s):  
Cell Division ◽  
Cell Surface ◽  
Cell Volume ◽  
Mother Cell ◽  
Daughter Cell ◽  
Tetrahymena Pyriformis ◽  
Posterior Pole ◽  
Live Cells ◽  
Final Position ◽  
Daughter Cells

The relative daughter cell volume (RDCV) values for Tetrahymena pyriformis were determined at division on live cells. It was found that the anterior cell is generally larger than the posterior cell, and that the RDCV values are distributed in groups 5–6% apart. The RDCV value was found to be independent of predivision cell volume, indicating that the mother cell is divided into proportional volumes. The cells seem, however, not to assess volume directly but rather a parameter related to the cell volume. Furthermore, the RDCV value was found to increase during cell division, so that the final value is not reached until actual separation of daughter cells. It is suggested that the division furrow is positioned so that the area of the cell surface lying between the old oral apparatus and the posterior pole of the cell is divided into equal parts. It is further suggested that several alternative values of the RDCV are possible, only one of which is expressed in each cell. The early division furrow is placed anteriorly to its final position, and its location is adjusted during cytokinesis.

Analysis of the temperature-sensitive period of the short-1 mutation affecting stomatogenesis in Paramecium tetraurelia

1987 ◽  
Vol 88 (2) ◽  
pp. 241-250
Author(s):  
LAI-WA TAM ◽  
STEPHEN F. NG
Keyword(s):  
Heat Shock ◽  
Sexual Reproduction ◽  
Temperature Shift ◽  
High Sensitivity ◽  
Sensitive Period ◽  
Temperature Sensitive ◽  
Basal Bodies ◽  
Paramecium Tetraurelia ◽  
Membrane Growth ◽  
Development Temperature

Reduction in the length of the oral apparatus produced by the temperature-sensitive mutation short-1 (sh1) involved suppressed growth of the oral primordium in all stages of development. Temperature shift-up and heat-shock experiments revealed that the temperature-sensitive period of this mutation coincided with nearly the entire stomatogenic phase (stages 1–6) in sexual reproduction. Low- and high-sensitivity phases were noted, corresponding to the periods of slow (stages 1 and 2) and rapid (stage 3 to stage 6) elongation of the oral primordium, respectively. The action of sh1 is thus concentrated after stage 2. The mutation hypothetically results in defective membrane growth and extension in the oral primordium, leading to restriction in incorporation of basal bodies into the developing membranelles.

scholarly journals Independent Localization of Plasma Membrane and Chloroplast Components during Eyespot Assembly

2013 ◽  
Vol 12 (9) ◽  
pp. 1258-1270 ◽  
Author(s):  
Telsa M. Mittelmeier ◽  
Mark D. Thompson ◽  
Esra Öztürk ◽  
Carol L. Dieckmann
Keyword(s):  
Plasma Membrane ◽  
Cell Division ◽  
Immunofluorescence Microscopy ◽  
Pigment Granule ◽  
Time Frame ◽  
Chloroplast Envelope ◽  
Basal Bodies ◽  
Content Type ◽  
Daughter Cells ◽  
Mutant Cells

ABSTRACTLike many algae,Chlamydomonas reinhardtiiis phototactic, using two anterior flagella to swim toward light optimal for photosynthesis. The flagella are responsive to signals initiated at the photosensory eyespot, which comprises photoreceptors in the plasma membrane and layers of pigment granules in the chloroplast. Phototaxis depends on placement of the eyespot at a specific asymmetric location relative to the flagella, basal bodies, and bundles of two or four highly acetylated microtubules, termed rootlets, which extend from the basal bodies toward the posterior of the cell. Previous work has shown that the eyespot is disassembled prior to cell division, and new eyespots are assembled in daughter cells adjacent to the nascent four-membered rootlet associated with the daughter basal body (D4), but the chronology of these assembly events has not been determined. Here we use immunofluorescence microscopy to follow assembly and acetylation of the D4 rootlet, localization of individual eyespot components in the plasma membrane or chloroplast envelope, and flagellar emergence during and immediately following cell division. We find that the D4 rootlet is assembled before the initiation of eyespot assembly, which occurs within the same time frame as rootlet acetylation and flagellar outgrowth. Photoreceptors in the plasma membrane are correctly localized in eyespot mutant cells lacking pigment granule layers, and chloroplast components of the eyespot assemble in mutant cells in which photoreceptor localization is retarded. The data suggest that plasma membrane and chloroplast components of the eyespot are independently responsive to a cytoskeletal positioning cue.

scholarly journals Test for temporal or spatial restrictions in gene product function during the cell division cycle.

1983 ◽  
Vol 3 (7) ◽  
pp. 1255-1265 ◽  
Author(s):  
S K Dutcher ◽  
L H Hartwell
Keyword(s):  
Cell Division ◽  
Gene Product ◽  
Gene Mutations ◽  
Cell Division Cycle ◽  
Temperature Sensitive ◽  
Restrictive Temperature ◽  
Product Function ◽  
Complete Cell ◽  
Relationship Of ◽  
Gene Product Function

The ability of a functional gene to complement a nonfunctional gene may depend upon the intracellular relationship of the two genes. If so, the function of the gene product in question must be limited in time or in space. CDC (cell division cycle) gene products of Saccharomyces cerevisiae control discrete steps in cell division; therefore, they constitute reasonable candidates for genes that function with temporal or spatial restrictions. In an attempt to reveal such restrictions, we compared the ability of a CDC gene to complement a temperature-sensitive cdc gene in diploids where the genes are located within the same nucleus to complementation in heterokaryons where the genes are located in different nuclei. In CDC X cdc matings, complementation was monitored in rare heterokaryons by assaying the production of cdc haploid progeny (cytoductants) at the restrictive temperature. The production of cdc cytoductants indicates that the cdc nucleus was able to complete cell division at the restrictive temperature and implies that the CDC gene product was provided by the other nucleus or by cytoplasm in the heterokaryon. Cytoductants from cdc28 or cdc37 crosses were not efficiently produced, suggesting that these two genes are restricted spatially or temporally in their function. We found that of the cdc mutants tested 33 were complemented; cdc cytoductants were recovered at least as frequently as CDC cytoductants. A particularly interesting example was provided by the CDC4 gene. Mutations in CDC4 were found previously to produce a defect in both cell division and karyogamy. Surprisingly, the cell division defect of cdc4 nuclei is complemented by CDC4 nuclei in a heterokaryon, whereas the karyogamy defect is not.

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 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.

scholarly journals Cytoskeleton-secretory vesicle interactions during the docking of secretory vesicles at the cell membrane in Paramecium tetraurelia cells.

1982 ◽  
Vol 92 (2) ◽  
pp. 368-377 ◽  
Author(s):  
H Plattner ◽  
C Westphal ◽  
R Tiggemann
Keyword(s):  
Cell Surface ◽  
Attachment Site ◽  
Secretory Vesicle ◽  
Basal Bodies ◽  
Secretory Vesicles ◽  
Paramecium Tetraurelia ◽  
Long Distance ◽  
Microfilament Bundles ◽  
Attachment Sites ◽  
Saltatory Movement

Stationary-phase cells of Paramecium tetraurelia have most of their many secretory vesicles ("trichocysts") attached to the cell surface. Log-phase cells contain numerous unoccupied potential docking sites for trichocysts and many free trichocysts in the cytoplasm. To study the possible involvement of cytoskeletal elements, notably of microtubules, in the process of positioning of trichocysts at the cell surface, we took advantage of these stages. Cells were stained with tannic acid and subsequently analyzed by electron microscopy. Semithin sections allowed the determination of structural connections over a range of up to 10 micrometer. Microtubules emanating from ciliary basal bodies are seen in contact with free trichocysts, which appear to be transported, with their tip first, to the cell surface. (This can account for the saltatory movement reported by others). It is noteworthy that the "rails" represented by the microtubules do not directly determine the final attachment site of a trichocyst. Unoccupied attachment sites are characterized by a "plug" of electron-dense material just below the plasma membrane; the "plug" seems to act as a recognition or anchoring site; this material is squeezed out all around the trichocyst attachment zone, once a trichocyst is inserted (Westphal and Plattner, in press. [53]). Slightly below this "plug" we observed fasciae of microfilaments (identified by immunocytochemistry using peroxidase labeled F(ab) fragments against P. tetraurelia actin). Their arrangement is not altered when a trichocyst is docked. These fasciae seem to form a loophole for the insertion of a trichocyst. Trichocyst remain attached to the microtubules originating from the ciliary basal bodies--at least for some time--even after they are firmly installed in the preformed attachment sites. Evidently, the regular arrangement of exocytotic organelles is controlled on three levels: one operating over a long distance from the exocytosis site proper (microtubules), one over a short distance (microfilament bundles), and one directly on the exocytosis site ("plug").

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.

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