Variations in the distribution and migration of centriole duplexes in mitotic PtK2 cells studied by immunofluorescence microscopy

1980 ◽  
Vol 43 (1) ◽  
pp. 177-194 ◽  
Author(s):  
J.E. Aubin ◽  
M. Osborn ◽  
K. Weber
Keyword(s):  
Nuclear Membrane ◽  
Immunofluorescence Microscopy ◽  
Cytoplasmic Microtubule ◽  
Migration Patterns ◽  
Large Variability ◽  
Membrane Breakdown ◽  
Large Populations ◽  
Tubulin Antibodies ◽  
Cytoplasmic Microtubules ◽  
And Migration

The localization and migration of centriole duplexes have been studied in PtK2 cells by indirect immunofluorescence microscopy using specific tubulin antibodies. The study demonstrated the usefulness of the immunofluorescence technique to quantitate studies of centriole migration and concomitant events such as cytoplasmic microtubule breakdown in large populations of cells. Centriole duplex locations in normal and Colcemid-treated interphase populations have been compared with duplex locations in prophase cells. A higher percentage of duplexes were found close to the nucleus in prophase than in interphase cells, but approximately 5% of the duplexes remained in the cytoplasm far removed from the nucleus in prophase and throughout the course of duplex separation. Duplex separation occurred along a wide variety of paths and duplexes did not have to be closely juxtaposed to the nuclear envelope for separation to occur. Some duplexes separated in the cytoplasm with no detectable nuclear attachment, with spindles forming far to the side of the condensing chromosomes. The timing of duplex separation did not always coincide either with chromosome condensation or with nuclear membrane breakdown, and in a small percentage of the cells separation occurred as late as prometaphase. These data suggest that normal spindle formation can occur despite the large variability in initial and final centriole duplex location, their migration patterns, and the timing of the different events. Breakdown of cytoplasmic microtubules began in prophase and progressed until prometaphase; the last cytoplasmic microtubules disappeared soon after the loss of the nuclear membrane.

scholarly journals Individual microtubules viewed by immunofluorescence and electron microscopy in the same PtK2 cell

1978 ◽  
Vol 77 (3) ◽  
pp. R27 ◽  
Author(s):  
M Osborn ◽  
RE Webster ◽  
K Weber
Keyword(s):  
Electron Microscopy ◽  
Electron Microscope ◽  
Light Microscope ◽  
Immunofluorescence Microscopy ◽  
Uranyl Acetate ◽  
Tubulin Antibodies ◽  
Ptk2 Cell ◽  
Cytoplasmic Microtubules ◽  
Triton X ◽  
Microtubular Structures

PtK2 cells were grown on gold grids and treated with Triton X-100 in a microtubule stabilizing buffer. The resulting cytoskeletons were fixed with glutaraldehyde and subjected to the indirect immunofluorescence procedure using monospecific tubulin antibodies. Grids were examined first by fluorescence microscopy, and the display of fluorescent cytoplasmic microtubules was recorded. The grids were then stained with uranyl acetate and the display of fibrous structures recorded by electron microscopy. Thus the display of cytoplasmic microtubular structures in the light microscope and the electron microscope can be compared within the same cytoskeleton. The results show a direct correspondence of the fluorescent fibers in the light microscope with uninterrupted fibers of diameter approximately 550 A in the electron microscope. This is the diameter reported for a single microtubule decorated around its circumference by two layers of antibody molecules. Thus under optimal conditions immunofluorescence microscopy can visualize individual microtubules.

scholarly journals Ccdc103 promotes myeloid cell proliferation and migration independent of motile cilia

2021 ◽  
Author(s):  
Lauren G. Falkenberg ◽  
Sarah A. Beckman ◽  
Padmapriyadarshini Ravisankar ◽  
Tracy E. Dohn ◽  
Joshua S. Waxman
Keyword(s):  
Coiled Coil ◽  
Myeloid Cells ◽  
Myeloid Cell ◽  
Cytoplasmic Microtubule ◽  
Microtubule Stability ◽  
Cytoplasmic Microtubules ◽  
Motile Cilia ◽  
And Migration ◽  
Ciliary Dyskinesia ◽  
Functional Defects

The pathology of primary ciliary dyskinesia (PCD) is predominantly attributed to impairment of motile cilia. However, PCD patients also have perplexing functional defects in myeloid cells, which lack motile cilia. Here, we show Coiled-coil domain containing protein 103 (CCDC103), one of the genes that when mutated is known to cause PCD, is required for the proliferation and directed migration of myeloid cells. CCDC103 is expressed in human myeloid cells, where it co-localizes with cytoplasmic microtubules. Zebrafish ccdc103/schmalhans (smh) mutants have macrophages and neutrophils with reduced proliferation, abnormally-rounded cell morphology, and an inability to migrate efficiently to the site of sterile wounds, all of which are consistent with a loss of cytoplasmic microtubule stability. Furthermore, we demonstrate that direct interactions between CCDC103 and Sperm associated antigen 6 (SPAG6), which also promotes microtubule stability, are abrogated by CCDC103 mutations from PCD patients, and that spag6 zebrafish mutants recapitulate the myeloid defects observed in smh mutants. In summary, we have illuminated a mechanism, independent of motile cilia, to explain functional defects in myeloid cells from PCD patients.

scholarly journals Selection for altruistic defense in structured populations

2019 ◽  
Author(s):  
Felix Jordan ◽  
Martin Hutzenthaler ◽  
Dirk Metzler
Keyword(s):  
Complete Separation ◽  
Structured Populations ◽  
Weak Selection ◽  
Asymptotic Results ◽  
Defense Behavior ◽  
Migration Patterns ◽  
Large Populations ◽  
Population Sizes ◽  
Selection For ◽  
And Migration

AbstractWe model natural selection for or against an altruistic defense allele of a host (or prey) against a parasite (or predator). The populations are structured in demes and we specify rates for birth, death, and migration events of single individuals. The defense behavior has a fitness cost for the actor and locally reduces parasite growth rates. In a previous study (Hutzenthaler et al., 2015), we analytically derived a criterion for fixation or extinction of altruists in the limit of large populations, many demes, weak selection and slow migration. Here, we use two simulation approaches to analyze the model in relaxed settings. We confirm that the criterion still holds for settings with finitely many demes with various migration patterns if populations are large and the ecological interactions are fast compared to evolutionary processes. For smaller populations with no complete separation of evolutionary and ecological time scales, the value of the shift between fixation and extinction changes, but the qualitative insights remain valid. The key mechanism of providing a benefit of altruism is randomness of reproduction and death events leading to differences in population sizes between demes. Randomness, which is more pronounced for small populations, improves the conditions for fixation of the altruistic allele. Furthermore, as suggested by the previous asymptotic results, we find no significant effect of the migration rate and conclude that the amount of gene flow under which the evolution of altruism is favored may not be as limited as suggested by previous studies.

Population trends and migration patterns in the critically endangered Yellow-breasted Bunting (Emberiza aureola) in the Republic of Korea

2020 ◽  
Vol 27 (1) ◽  
pp. 56-63
Author(s):  
Jong-Gil Park ◽  
Chang-uk Park ◽  
Kyoung-Soon Jin ◽  
Yang-Mo Kim ◽  
Hee-Young Kim ◽  
...  
Keyword(s):  
Population Trends ◽  
Critically Endangered ◽  
Republic Of Korea ◽  
Migration Patterns ◽  
The Republic ◽  
And Migration

scholarly journals Spatial and space-time correlations in systems of subpopulations with genetic drift and migration.

Genetics ◽  
1993 ◽  
Vol 133 (3) ◽  
pp. 711-727
Author(s):  
B K Epperson
Keyword(s):  
Population Genetics ◽  
Time Correlation ◽  
Space Time ◽  
Spatial Correlations ◽  
Gene Frequencies ◽  
Migration Patterns ◽  
Migration Rates ◽  
Space And Time ◽  
Time Correlations ◽  
And Migration

Abstract The geographic distribution of genetic variation is an important theoretical and experimental component of population genetics. Previous characterizations of genetic structure of populations have used measures of spatial variance and spatial correlations. Yet a full understanding of the causes and consequences of spatial structure requires complete characterization of the underlying space-time system. This paper examines important interactions between processes and spatial structure in systems of subpopulations with migration and drift, by analyzing correlations of gene frequencies over space and time. We develop methods for studying important features of the complete set of space-time correlations of gene frequencies for the first time in population genetics. These methods also provide a new alternative for studying the purely spatial correlations and the variance, for models with general spatial dimensionalities and migration patterns. These results are obtained by employing theorems, previously unused in population genetics, for space-time autoregressive (STAR) stochastic spatial time series. We include results on systems with subpopulation interactions that have time delay lags (temporal orders) greater than one. We use the space-time correlation structure to develop novel estimators for migration rates that are based on space-time data (samples collected over space and time) rather than on purely spatial data, for real systems. We examine the space-time and spatial correlations for some specific stepping stone migration models. One focus is on the effects of anisotropic migration rates. Partial space-time correlation coefficients can be used for identifying migration patterns. Using STAR models, the spatial, space-time, and partial space-time correlations together provide a framework with an unprecedented level of detail for characterizing, predicting and contrasting space-time theoretical distributions of gene frequencies, and for identifying features such as the pattern of migration and estimating migration rates in experimental studies of genetic variation over space and time.

Distribution characteristics and migration patterns of hazardous trace elements in coal combustion products of power plants

Fuel ◽  
2019 ◽  
Vol 258 ◽  
pp. 116062 ◽  
Author(s):  
Jinxi Wang ◽  
Zhen Yang ◽  
Shenjun Qin ◽  
Balaji Panchal ◽  
Yuzhuang Sun ◽  
...  
Keyword(s):  
Trace Elements ◽  
Coal Combustion ◽  
Power Plants ◽  
Combustion Products ◽  
Distribution Characteristics ◽  
Migration Patterns ◽  
Coal Combustion Products ◽  
Hazardous Trace Elements ◽  
And Migration

scholarly journals Calmodulin-microtubule association in cultured mammalian cells.

1984 ◽  
Vol 98 (3) ◽  
pp. 904-910 ◽  
Author(s):  
W J Deery ◽  
A R Means ◽  
B R Brinkley
Keyword(s):  
Plasma Membrane ◽  
Mammalian Cells ◽  
Cell System ◽  
The Other ◽  
Microtubule Assembly ◽  
Cytoplasmic Microtubule ◽  
Hypotonic Treatment ◽  
Cytoplasmic Microtubules ◽  
Triton X ◽  
Ca Sensitivity

A Triton X-100-lysed cell system has been used to identify calmodulin on the cytoskeleton of 3T3 and transformed SV3T3 cells. By indirect immunofluorescence, calmodulin was found to be associated with both the cytoplasmic microtubule complex and the centrosomes. A number of cytoplasmic microtubules more resistant to disassembly upon either cold (0-4 degrees C) or hypotonic treatment, as well as following dilution have been identified. Most of the stable microtubules appeared to be associated with the centrosome at one end and with the plasma membrane at the other end. These microtubules could be induced to depolymerize, however, by micromolar Ca++ concentrations. These data suggest that, by interacting directly with the microtubule, calmodulin may influence microtubule assembly and ensure the Ca++-sensitivity of both mitotic and cytoplasmic microtubules.

scholarly journals Organization of the flagellar apparatus and associate cytoplasmic microtubules in the quadriflagellate alga Polytomella agilis.

1976 ◽  
Vol 69 (1) ◽  
pp. 106-125 ◽  
Author(s):  
D L Brown ◽  
A Massalski ◽  
R Patenaude
Keyword(s):  
Anterior Part ◽  
Flagellar Apparatus ◽  
Microtubule Assembly ◽  
Immunofluorescent Staining ◽  
Body Region ◽  
Basal Bodies ◽  
Cytoplasmic Microtubule ◽  
Large Numbers ◽  
Attachment Sites ◽  
Cytoplasmic Microtubules

The organization of microtubular systems in the quadriflagellate unicell Polytomella agilis has been reconstructed by electron microscopy of serial sections, and the overall arrangement confirmed by immunofluorescent staining using antiserum directed against chick brain tubulin. The basal bodies of the four flagella are shown to be linked in two pairs of short fibers. Light microscopy of swimming cells indicates that the flagella beat in two synchronous pairs, with each pair exhibiting a breast-stroke-like motion. Two structurally distinct flagellar rootlets, one consisting of four microtubules in a 3 over 1 pattern and the other of a striated fiber over two microtubules, terminate between adjacent basal bodies. These rootlets diverge from the basal body region and extend toward the cell posterior, passing just beneath the plasma membrane. Near the anterior part of the cell, all eight rootlets serve as attachment sites for large numbers of cytoplasmic microtubules which occur in a single row around the circumference of the cell and closely parallel the cell shape. It is suggested that the flagellar rootless may function in controlling the patterning and the direction of cytoplasmic microtubule assembly. The occurrence of similar rootlet structures in other flagellates is briefly reviewed.

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