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排序方式: 共有219条查询结果,搜索用时 822 毫秒
1.
Flow cytometric analysis and sorting of human endometrial cells after immunocytochemical labeling for cytokeratin using a monoclonal antibody 总被引:2,自引:0,他引:2
P S Oud J B Henderik H L Beck J A Veldhuizen G P Vooijs C J Herman F C Ramaekers 《Cytometry》1985,6(2):159-164
Endometrial cells in suspension were stained with propidium iodide and a monoclonal antibody against a cytokeratin intermediate filament protein specific for glandular and columnar cells (RGE 53). In this way columnar epithelial cells of the normal endometrium and of adenocarcinomas can be distinguished and separated by flow cytometry from non-epithelial cells (fibroblasts and inflammatory cells) and squamous epithelial cells, all of which are negative for RGE 53. This makes it possible to analyse and also sort pure fractions of this particular tissue type for further studies. The use of propidium iodide allows simultaneous DNA flow cytometry of these columnar epithelial cells. Therefore, the use of antibodies to cytokeratin in combination with propidium iodide can be of help in analyzing and sorting pure fractions of both normal and malignant cells. This allows a more refined examination of complex cell mixtures using flow cytometry. 相似文献
2.
Cells in the root meristem are organised in longitudinal files. Repeated transverse cell divisions in these files are the prime cause of root growth. Because of the orientation of the cell divisions, we expected to find mitoses with an spindle axis parallel to the file axis. However, we observed in the root cortex ofVicia faba large number of oblique chromosome orientations. From metaphase to telophase there was a dramatic increase of the rotation of the spindle axis. Measurements of both the size of the cortex cells and the chromosome configurations indicated that most cells were too small for an orientation of the spindle parallel to the file axis. Space limitation force the spindle into an oblique position. Despite this spindle axis rotation, most daughter cells remained within the original cell file. Only in extremely flat cells did the position of the daughter nuclei forced the cell to set a plane of division parallel to the file axis, which result in side-by-side orientation of the daughter cells. Telophase spindle axis rotations are also observed inCrepis capillaris andPetunia hybrida.. These species have respectively medium and small sized chromosomes compared toVicia. Since space limitation, which causes the rotation, depends both on cell and chromosome size, the frequency and extent of the phenomenon in former two species is comparatively low. 相似文献
3.
Summary Post-mitotic epidermal cells of barley leaves were found to contain, in addition to cortical microtubules (CMTs), distinct arrays of endoplasmic microtubules (EMTs). These encircle nuclei and continuously merge into the CMT arrays that underly the plasmalemma. Detailed three-dimensional reconstruction of both types of MTs during fungal infection showed that profound and very rapid MT rearrangements occurred especially in the case of incompatible (resistant) barley-powdery mildew genotype combination. The most early MT responses, followed by their subsequent complete disintegration, were recorded around nuclei. These events might be relevant for the induction of such nuclear processes as onset of DNA synthesis and nuclear chromatin condensation. Observed pattern of early infection events, as well as less prominent responses in the case of compatible (susceptible) barley-powdery mildew genotype combination, both findings suggest that rapid reorganization of the MT cytoskeleton could be involved in recognition of the fungus by host cells and in the initiation of resistance responses in barley leaves. We hypothesize that the integrity and dynamics of the MT cytoskeleton, especially of its perinuclear part, might participate in control mechanisms involved in activation of resistance genes.Abbreviations CMTs
cortical microtubules
- EMTs
endoplasmic microtubules
- MT
microtubules
- PI
propidium iodide
- SC
sensitive combination
- RC
resistant combination 相似文献
4.
Bastiaan L. Slierendregt Nel Otting Marcel Kenter Ronald E. Bontrop 《Immunogenetics》1995,41(1):29-37
Allelic diversity at the major histocompatibility complex class II DP locus of rhesus macaques was studied by sequencing exon 2 of Mamu-DPA1 and -DPB1 genes. The Mamu-DPA1 gene is apparently invariant, whereas the Mamu-DPB1 locus displays polymorphism. Here we report the characterization of 1 Mamu-DPA1 and 13 Mamu-DPB1 alleles which were compared with other available primate Mhc-DPA1 and -DPB1 sequences. As compared with Mhc-DRB and -DQB1, most codons for the contact residues in the antigen binding site of the primate Mhc-DPB1 gene have a relatively low degree of variation in encoding various types of amino acids. In contrast to Mhc-DRB and -DQB, the HLA- and Mamu-DPB1 sequences cluster in a species-specific manner in phylogenetic trees. Mhc-DPB1 polymorphisms, however, are inherited in a transspecies mode of evolution, as is demonstrated by the sharing of lineage members between closely related macaque species. The data demonstrate that the transspecies character of Mhc-DPB1 polymorphism was retained over much shorter periods of time as compared with its sister class II loci, Mhc-DQ and -DR.The nucleotide sequence data reported in this paper have been submitted to the EMBL nucleotide sequence database and have been assigned the accession numbers Z32402–Z32415 相似文献
5.
P. S. Oud J. B. J. Henderik A. C. L. M. Huysmans M. M. M. Pahlplatz H. G. Hermkens J. Tas J. James G. P. Vooijs 《Histochemistry and cell biology》1984,80(1):49-57
Summary The protein dyes Light Green and Orange II were studied separately and in combination with the Feulgen-Pararosanilin(SO2) and-Thionin(SO2) method for the simultaneous determination of DNA and protein. — With polyacrylamide modelfilms the pH dependency, specificity and stoichiometry of Light Green and Orange II have been investigated. The results of both staining methods with different biological objects have been compared. — In addition, the Feulgen-Thionin(SO2) method was studied with model films with respect to its specificity and stoichiometry. In biological objects it has been compared with the Feulgen-Pararosanilin(SO2) method. — When combining the Light Green staining with the Feulgen-Pararosanilin(SO2) procedure and the Orange II staining with Feulgen-Thionin-(SO2), both Feulgen-DNA stainings, which were first applied, proved to be unaffected by the following protein staining procedure. When the Feulgen procedure was carried out without the dye, followed by Light Green staining, the latter became reduced when a sulfite water rinse was included but was unaffected when a running tap water rinse was used. In the case of the Orange II staining a serious reduction in dye binding capacity was found in both situations. — When the Feulgen-Pararosanilin(SO2) Light Green procedure was carried out on isolated nuclei with all dyes present, a decrease of protein dye binding was observed, similar to that found with the well-known Feulgen-Pararosanilin(SO2) Naphthol Yellow S combination. It is concluded that in spite of this reduction the latter two combinations can be used for the cytophotometric analysis of DNA and protein in the same object.This work was supported by the Dutch Cancer Foundation Koningin Wilhelmina Fonds grant NUKC 1981-15 相似文献
6.
The staining of male Chinese hamster chromosomes at meiotic prophase with several banding techniques is described. C-banding results only occasionally in well-differentiated pachytene and diakinesis bivalents. Meiotic C-bands are small compared with those in somatic metaphase chromosomes. In mice C-bands mainly consist of highly repetitive satellite DNA, whereas in Chinese hamsters the majority of the DNA in C-bands is not or hardly repetitive. Especially in Chinese hamsters both the degree of chromatin despiralisation and the folding pattern of the chromatin drastically reduce the distinction of C-bands in late meiotic prophasc chromosomes. In contrast to the situation in mice, C-heterochromatin associations are never observed in Chinese hamster spermatocytes. It is assumed that the presence of satellite DNA rather than constitutive heterochromatin is the basis for the associations of the paracentromeric chromosome regions in mice. The location and behaviour of AT- and GC-rich DNA in Chinese hamster primary spermatocytes is studied with base-specific fluorochromes (H 33258 and Chromomycin A3 for AT-and GC-rich DNA respectively), in combination with a pretreatment with base-specific non-fluorescent antibiotics (Actinomycin D and Netropsin for GC-and AT-rich DNA respectively). No indications are found for the clustering of AT-or GC-rich DNA in Chinese hamster pachytene nuclei. A comparison of banding patterns observed in somatic metaphases and in diakinesis gives some information about the partial homology of the X and Y chromosome. The results are conflicting. The short arm of the Y chromosome is homologous with a part of the X chromosome. According to the C-band pattern the long arm of the X chromosome is involved in the pairing with Y, whereas fluorescence banding patterns indicate that it is the short arm of X. 相似文献
7.
8.
J. L. Oud 《Genetica》1973,44(3):416-427
The eleven chromosome bivalents of the Chinese hamster at diakinesis can be identified on account of their morphology, in combination with the fluorescence pattern. Comparison of the fluorescence pattern of the sex-chromosomes in both mitosis and meiosis shows that the distal part of the short arm of the X chromosome is homologous with part of the Y chromosome. It is not possible, however, to decide with certainty which part of the Y chromosome is involved. 相似文献
9.
Environmental heterogeneity has long been considered a likely explanation for the high levels of genetic variation found in most natural populations: selection in a spatially heterogeneous environment can maintain more variation. While this theoretical result has been extensively studied in models with limited parameters (e.g., two alleles, fixed gene flow, and particular selection schemes), the effect of spatial heterogeneity is poorly understood for models with a wider range of parameters (e.g., multiple alleles, different levels of gene flow, and more general selection schemes). We have compared the volume of fitness space that maintains variation in a single-deme model to the volume in a two-deme model for multiple alleles, random selection schemes, and various levels of migration. Furthermore, equilibrium allele-frequency vectors were examined to see if particular patterns of variation are more prevalent than first expected. The two-deme model maintains variation for substantially larger volumes of fitness space with lower heterozygote fitness than the single-deme model. This result implies that selection schemes in the two-deme model can have a wider range of fitness patterns while still maintaining variation. The equilibrium allele-frequency patterns emerging from the two-deme model are more variable and strongly influenced by gene flow. 相似文献
10.
Roderick C. Slieker Matthias S. Roost Liesbeth van Iperen H. Eka D. Suchiman Elmar W. Tobi Fran?oise Carlotti Eelco J. P. de Koning P. Eline Slagboom Bastiaan T. Heijmans Susana M. Chuva de Sousa Lopes 《PLoS genetics》2015,11(10)
Remodelling the methylome is a hallmark of mammalian development and cell differentiation. However, current knowledge of DNA methylation dynamics in human tissue specification and organ development largely stems from the extrapolation of studies in vitro and animal models. Here, we report on the DNA methylation landscape using the 450k array of four human tissues (amnion, muscle, adrenal and pancreas) during the first and second trimester of gestation (9,18 and 22 weeks). We show that a tissue-specific signature, constituted by tissue-specific hypomethylated CpG sites, was already present at 9 weeks of gestation (W9). Furthermore, we report large-scale remodelling of DNA methylation from W9 to W22. Gain of DNA methylation preferentially occurred near genes involved in general developmental processes, whereas loss of DNA methylation mapped to genes with tissue-specific functions. Dynamic DNA methylation was associated with enhancers, but not promoters. Comparison of our data with external fetal adrenal, brain and liver revealed striking similarities in the trajectory of DNA methylation during fetal development. The analysis of gene expression data indicated that dynamic DNA methylation was associated with the progressive repression of developmental programs and the activation of genes involved in tissue-specific processes. The DNA methylation landscape of human fetal development provides insight into regulatory elements that guide tissue specification and lead to organ functionality. 相似文献