Visualization of kinetochores in mammalian meiotic preparations and observations of argentophilic differences between mitotic and meiotic kinetochores

Genome ◽  
1989 ◽  
Vol 32 (3) ◽  
pp. 380-382 ◽  
Author(s):  
Philip D. Sudman ◽  
Ira F. Greenbaum
Keyword(s):  
Silver Staining ◽  
Constitutive Heterochromatin ◽  
Structural Difference ◽  
Metaphase Chromosomes ◽  
Positive Identification ◽  
Valuable Method ◽  
Centromeric Position ◽  
Spermatogonial Metaphase ◽  
Position And Orientation ◽  
Kinetochore Region

Brief staining with AgNO3 was found to differentially stain the kinetochores of chromosomes from diakinesis – metaphase I and metaphase II nuclei of mammals. The results differ from those of Giemsa-stained or C-banded preparations as the silver-stained meiotic kinetochores are clearly distinguishable from both constitutive heterochromatin and euchromatin. Silver-staining is presented as a valuable method for the staining of meiotic material because it allows for the positive identification of centromeric position and orientation with respect to chiasmata. The nonargentophilic nature of the centromere (kinetochore) region of spermatogonial metaphase chromosomes in some species suggests a fundamental structural difference between mitotic and meiotic kinetochores.Key words: kinetochore, meiosis, mammal.

scholarly journals Human centromere chromatin protein hMis12, essential for equal segregation, is independent of CENP-A loading pathway

2003 ◽  
Vol 160 (1) ◽  
pp. 25-39 ◽  
Author(s):  
Gohta Goshima ◽  
Tomomi Kiyomitsu ◽  
Kinya Yoda ◽  
Mitsuhiro Yanagida
Keyword(s):  
Chromosome Segregation ◽  
Vital Role ◽  
Chromatin Protein ◽  
Human Homologue ◽  
Metaphase Chromosomes ◽  
Conserved Sequence ◽  
Human Centromere ◽  
Mitotic Delay ◽  
Higher Eukaryotes ◽  
Kinetochore Region

Kinetochores are the chromosomal sites for spindle interaction and play a vital role for chromosome segregation. The composition of kinetochore proteins and their cellular roles are, however, poorly understood in higher eukaryotes. We identified a novel kinetochore protein family conserved from yeast to human that is essential for equal chromosome segregation. The human homologue hMis12 of yeast spMis12/scMtw1 retains conserved sequence features and locates at the kinetochore region indistinguishable from CENP-A, a centromeric histone variant. RNA interference (RNAi) analysis of HeLa cells shows that the reduced hMis12 results in misaligned metaphase chromosomes, lagging anaphase chromosomes, and interphase micronuclei without mitotic delay, while CENP-A is located at kinetochores. Further, the metaphase spindle length is abnormally extended. Spindle checkpoint protein hMad2 temporally localizes at kinetochores at early mitotic stages after RNAi. The RNAi deficiency of CENP-A leads to a similar mitotic phenotype, but the kinetochore signals of other kinetochore proteins, hMis6 and CENP-C, are greatly diminished. RNAi for hMis6, like that of a kinetochore kinesin CENP-E, induces mitotic arrest. Kinetochore localization of hMis12 is unaffected by CENP-A RNAi, demonstrating an independent pathway of CENP-A in human kinetochores.

NUCLEOLAR ORGANIZER REGIONS IN THE RABBIT (ORYCTOLAGUS CUNICULUS) AS SHOWN BY SILVER STAINING

1978 ◽  
Vol 20 (3) ◽  
pp. 377-382 ◽  
Author(s):  
Patricia A. Martin-Deleon ◽  
Dorene L. Petrosky ◽  
M. Eileen Fleming
Keyword(s):  
New Zealand ◽  
Silver Staining ◽  
Oryctolagus Cuniculus ◽  
Nucleolar Organizer ◽  
Nucleolar Organizer Regions ◽  
Telomeric Region ◽  
Metaphase Chromosomes ◽  
Domestic Rabbit ◽  
Silver Precipitation ◽  
Secondary Constrictions

Nucleolar organizer regions (NOR's) were demonstrated in metaphase chromosomes of the domestic rabbit, Oryctolagus cuniculus (L.) (New Zealand white strain) using silver staining. Sequential quinacrine banding and a modification of the Ag-AS silver precipitation technique with duplicate photography allowed identification of silver staining NOR's on the short arms of chromosomes 13, 16, and 20, as well as the telomeric region of the long arms of number 21 in some cells. Chromosomes 13, 16 and 20 all have subterminal to terminal centromeres, often showed satellites and secondary constrictions, and were sometimes involved in associations.

Differential silver staining of chromatin in metaphase chromosomes

1982 ◽  
Vol 141 (1) ◽  
pp. 117-125 ◽  
Author(s):  
Huai-Zu Zheng ◽  
Gary D. Burkholder
Keyword(s):  
Silver Staining ◽  
Metaphase Chromosomes

scholarly journals Fractionation and initial characterization of the kinetochore from mammalian metaphase chromosomes.

1985 ◽  
Vol 101 (3) ◽  
pp. 1124-1134 ◽  
Author(s):  
M M Valdivia ◽  
B R Brinkley
Keyword(s):  
Micrococcal Nuclease ◽  
Esophageal Dysmotility ◽  
Chromosomal Dna ◽  
Metaphase Chromosomes ◽  
Centromeric Chromatin ◽  
Chromosomal Proteins ◽  
Initial Characterization ◽  
Total Dna ◽  
Kinetochore Region

We have partially isolated the kinetochore and associated centromeric structures from mammalian metaphase chromosomes. Human autoantibodies from scleroderma CREST (calcinosis, Raynaud's phenomenon, esophageal dysmotility, sclerodactyly, telangiectasia) patients were used as immunofluorescent probes to monitor fractionation. The procedure includes digestion of total chromosomal DNA with micrococcal nuclease, dehistonization with heparin, and dissociation of the remaining material with detergent and urea. We used a density gradient (metrizamide) to obtain an enriched fraction of stained material (kinetochore). When examined by electron microscopy, the kinetochore fraction is seen to contain numerous small immunoperoxidase-positive masses which are morphologically similar to the centromere/kinetochore region of intact metaphase chromosomes. The particulate fraction that contains kinetochore components represents less than 5% of total chromosomal proteins and contains less than 1% of total DNA. Two polypeptides of 18 and 80 kD were identified as kinetochore antigens by immunoblotting with CREST antiserum. In this paper we discuss the distribution of these kinetochore polypeptides with the associated centromeric chromatin.

scholarly journals Genome restructuring in rye affects the expression, organization and disposition of homologous rDNA loci

2002 ◽  
Vol 115 (14) ◽  
pp. 2839-2846
Author(s):  
Ana D. Caperta ◽  
Nuno Neves ◽  
Leonor Morais-Cecílio ◽  
Rui Malhó ◽  
Wanda Viegas
Keyword(s):  
Silver Staining ◽  
Organizer Region ◽  
Expression Patterns ◽  
Nucleolar Organizer Region ◽  
Nucleolar Organizer ◽  
Parental Origin ◽  
Metaphase Chromosomes ◽  
Structural Variant ◽  
Sequence Recognition ◽  
Rdna Loci

The standard rye cultivar `Imperial' and a structural variant carrying an intact 1R chromosome and two telocentric 1R chromosomes (short and long arms)were used to investigate expression patterns of homologous rDNA loci, and the influence of chromosome structural change on their interphase organisation and relative disposition. Sequential silver staining and in situ hybridization with the rDNA probe pTa71, established a correspondence between the expression and organization patterns of rDNA domains in metaphase and interphase cells. In most cells of the cultivar Imperial, nucleolar organizer region (NOR)silver staining on metaphase chromosomes with equivalent numbers of rDNA genes revealed a size heteromorphism between homologous rDNA loci, resulting from their differential expression. NOR heteromorphism in the structural variant line was significantly reduced. The preferential activity of one NOR over its homologue was found to be random within cells and independent of parental origin. Nucleotypic modifications mediated by changes in the 1R chromosome structure include increased proximity between homologous rDNA loci in interphase, and an increase in the frequency of cells with intra-nucleolar ribosomal condensed chromatin. These results seem to indicate a `sequence recognition' process for the regulation of homologous loci.

C-banded karyotypes of Brassica campestris, B. oleracea, and B. napus

Genome ◽  
1992 ◽  
Vol 35 (4) ◽  
pp. 583-589 ◽  
Author(s):  
Majlis Olin-Fatih ◽  
W. K. Heneen
Keyword(s):  
Banding Pattern ◽  
Chromosome Pair ◽  
Brassica Campestris ◽  
Brassica Species ◽  
Conclusive Evidence ◽  
Metaphase Chromosomes ◽  
Late Prophase ◽  
Nucleolar Chromosome ◽  
Centromeric Position ◽  
Similar Banding Pattern

The chromosome complements of three Brassica species, namely B. campestris (2n = 20), B. oleracea (2n = 18), and B. napus (2n = 38), were studied using the air-dry method and C-banding. Karyotypes and ideograms of late prophase chromosomes were constructed, since contracted metaphase chromosomes were generally not suitable for this purpose. The three species generally had a similar banding pattern, manifested in the presence of a centromeric C-band in all chromosomes and heterochromatic knobs at the telomeric end of some chromosomes. The centromeric C-bands were more pronounced in B. campestris than in B. oleracea. Depending on the centromeric position, the chromosomes were grouped into median, submedian, subterminal, and terminal types. All chromosome pairs were morphologically distinguishable. Only one nucleolar chromosome pair, with heterochromatic satellites, was observed in each species. When compared, it was possible to distinguish chromosomes of both B. campestris and B. oleracea type in B. napus, but conclusive evidence as to the origin of all chromosome pairs in B. napus was not at hand.Key words: Brassica, chromosomes, late prophase, C-bands, knob structures, karyotypes, idiograms.

Karyotypic and chromosome banding studies of the potato tuber moth, Phthorimaea operculella (Zeller) (Lepidoptera, Gelechiidae)

1984 ◽  
Vol 26 (2) ◽  
pp. 141-145 ◽  
Author(s):  
D. G. Bedo
Keyword(s):  
Silver Staining ◽  
Chromosome Banding ◽  
Phthorimaea Operculella ◽  
Holocentric Chromosomes ◽  
Potato Tuber Moth ◽  
Considerable Variability ◽  
Fluorescent Staining ◽  
Hoechst 33258 ◽  
Metaphase Chromosomes ◽  
C Banding

The karyotype of Phthorimaea operculella is similar in both sexes and consists of 29 chromosome pairs. These are of similar size with gradual intergradation except for one pair which is significantly longer. C-banding and fluorescent staining with quinacrine and Hoechst 33258 failed to induce bands in metaphase chromosomes while silver staining clearly showed active nucleoli in all stages except metaphase. The banding results are compared with the few reports available on banding of holocentric chromosomes. It is concluded that considerable variability exists in the heterochromatic structure of holocentric chromosomes.Key words: Lepidoptera, moth, karyotype, C-banding.

Differentiation of four taxa of the Anopheles balabacensis complex using H-banding patterns in the sex chromosomes

1984 ◽  
Vol 26 (4) ◽  
pp. 425-429 ◽  
Author(s):  
S. Wibowo ◽  
V. Baimai ◽  
R. G. Andre
Keyword(s):  
Sex Chromosomes ◽  
Species Differences ◽  
Constitutive Heterochromatin ◽  
Staining Technique ◽  
Hoechst 33258 ◽  
Metaphase Chromosomes ◽  
Banding Patterns ◽  
Morphological Studies ◽  
Anopheles Balabacensis ◽  
Distinct Taxon

Analyses of metaphase chromosomes of four taxa of the Anopheles balabacensis complex (A. dirus A, B, and C, and A. takasagoensis) using the Hoechst 33258 staining technique have revealed remarkable differences in the fluorescence banding patterns of the sex chromosomes. These result from changes in the amount and distribution of constitutive heterochromatin. This evidence supports the results from cross-mating experiments and from morphological studies which indicate that three of these taxa, A. takasagoensis, dirus A, and dirus B, are sibling species. Differences in H-staining patterns of the sex chromosomes of a dirus colony from Kanchanaburi suggest that it too is a genetically distinct taxon, provisionally designated as dirus C, within the A. balabacensis complex.Key words: Anopheles, H-banding, heterochromatin, sex chromosomes.

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