FLUORESCENT PROBES OF CHROMOSOME STRUCTURE AND REPLICATION

1977 ◽  
Vol 19 (4) ◽  
pp. 603-623 ◽  
Author(s):  
Samuel A. Latt

Procedures employing fluorescent dyes or Giemsa stain have been utilized to differentiate metaphase chromosomes into longitudinal segments termed bands. In spite of the immense practical utility of chromosome banding, the chemical basis of banding patterns remains incompletely understood. Physical chemical studies have elucidated the modes and specificities of the interaction of fluorescent dyes such as quinacrine, 33258 Hoechst, daunomycin, chromomycin A3 and 7-aminoactinomycin D with DNA and chromatin. However, it is not clear that all aspects of chromosome staining are explainable in terms of the optical properties of soluble dye-DNA complexes. BrdU-dye techniques in which chromosome staining depends on the schedule of BrdU incorporation by cells, have been used for cytological studies of chromosome structure and replication. These procedures have revealed a close association between quinacrine or Giemsa bands and late replicating chromosomal regions. Biochemical studies on chromatin differentially labelled according to replication timing may thus prove useful for investigating the molecular basis of chromosome banding.

1976 ◽  
Vol 18 (1) ◽  
pp. 85-91 ◽  
Author(s):  
T. J. Ennis

Chromosome replication has been analysed in four species of Chilocorus. In C. orbus Csy., C. tricyclus Smith, and C. hexacyclus Smith, centric regions of all chromosomes are last to replicate, preceded in order by heterochromatic arms and euchromatic arms. In C. stigma Say, very late replication of centric regions can be detected only in otherwise wholly euchromatic chromosomes (= monophasics); in chromosomes with one arm heterochromatic (= diphasics), these arms are last to replicate. Based on pachytene bivalent morphology and chromosome banding patterns, and supported by autoradiographic data, models are presented for the general organisation of Chilocorus chromosomes. All chromosomes in the first three species are subdivided into euchromatic arm, centric heterochromatin, and either a second euchromatic arm (monophasics) or a heterochromatic arm (diphasics). Chilocorus stigma diphasics apparently lack distinct centric organisation, and are therefore divided into euchromatic and heterochromatic arms only.


Genome ◽  
1995 ◽  
Vol 38 (5) ◽  
pp. 1052-1055 ◽  
Author(s):  
L. P. Pijnacker ◽  
M. A. Ferwerda

Banding techniques were carried out on metaphase chromosomes of zebrafish (Danio rerio) embryos. The karyotypes with the longest chromosomes consist of 12 metacentrics, 26 submetacentrics, and 12 subtelocentrics (2n = 50). All centromeres are C-band positive. Eight chromosomes have a pericentric C-band in each arm and 22 chromosomes have one in the longest arm. Two chromosomes have a slightly heterochromatic long arm and five chromosomes have an Ag-NOR at the terminal end of the long arm. Other banding patterns and sex chromosomes could not be revealed.Key words: zebrafish, karyotype, chromosome banding.


Author(s):  
R. Levi-Setti ◽  
J. M. Chabala ◽  
R. Espinosa ◽  
M. M. Le Beau

We have shown previously that isotope-labelled nucleotides in human metaphase chromosomes can be detected and mapped by imaging secondary ion mass spectrometry (SIMS), using the University of Chicago high resolution scanning ion microprobe (UC SIM). These early studies, conducted with BrdU- and 14C-thymidine-labelled chromosomes via detection of the Br and 28CN- (14C14N-> labelcarrying signals, provided some evidence for the condensation of the label into banding patterns along the chromatids (SIMS bands) reminiscent of the well known Q- and G-bands obtained by conventional staining methods for optical microscopy. The potential of this technique has been greatly enhanced by the recent upgrade of the UC SIM, now coupled to a high performance magnetic sector mass spectrometer in lieu of the previous RF quadrupole mass filter. The high transmission of the new spectrometer improves the SIMS analytical sensitivity of the microprobe better than a hundredfold, overcoming most of the previous imaging limitations resulting from low count statistics.


Genome ◽  
1990 ◽  
Vol 33 (5) ◽  
pp. 686-689 ◽  
Author(s):  
Charles M. Papa ◽  
R. Morris ◽  
J. W. Schmidt

Two winter hexaploid triticale populations derived from the same cross were selected on the basis of grain appearance and agronomic performance. The five lines from 84LT402 showed more kernel shriveling than the four lines from 84LT401. The derived lines were analyzed for aneuploid frequencies, rye chromosome banding patterns, and meiotic stability to detect associations with kernel development. The aneuploid frequencies were 16% in 84LT401 and 18% in 84LT402. C-banding showed that both selection groups had all the rye chromosomes except 2R. The two groups had similar telomeric patterns but differed in the long-arm interstitial patterns of 4R and 5R. Compared with lines from 84LT402, those from 84LT401 had significantly fewer univalents and rod bivalents, and more paired arms at metaphase I; fewer laggards and bridges at anaphase I; and a higher frequency of normal tetrads. There were no significant differences among lines within each group for any meiotic character. Since there were no differences within or between groups in telomeric banding patterns, the differences in kernel shriveling and meiotic stability might be due to genotypic factors and (or) differences in the interstitial patterns of 4R and 5R. By selecting plump grains, lines with improved kernel characteristics along with improved meiotic stability are obtainable.Key words: triticale, meiotic stability, C-banding, Secale cereale, heterochromatin.


1973 ◽  
Vol 12 (1) ◽  
pp. 263-274
Author(s):  
P. W. ALLDERDICE ◽  
O. J. MILLER ◽  
D. A. MILLER ◽  
D. WARBURTON ◽  
P. L. PEARSON ◽  
...  

The fluorescent banding patterns of quinacrine-stained metaphase chromosomes have been studied in 2 related mouse cell lines, A9 and a malignant derivative of A9, A9HT. In both cell lines virtually every chromosome has a distinctive banding pattern which permits its recognition. More than three quarters of the chromosomes have structural rearrangements, but the origin of nearly two thirds of the chromosomes could be determined by their banding patterns. The quinacrine fluorescence technique permits far more detailed characterization and comparison of heteroploid cell lines than any previous method. A9 and A9HT are karyologically quite similar, with many of the same marker chromosomes. There are, however, characteristic differences. A9HT, although it has a smaller average number of chromosomes per cell, appears to be more heterogeneous.


2015 ◽  
Vol 147 (1) ◽  
pp. 70-79 ◽  
Author(s):  
Martin Röser

The endemic, highly polyploid, monotypic Madagascan palm genus Voanioala (2n ≈ 606) was studied with regard to mitotic stages and interphase. Features of the cell cycle, morphology and sizes of metaphase chromosomes, fluorochrome banding patterns, and silver staining of NORs of such an extremely high polyploid organism are reported for the first time. On a whole, karyokinesis appears to be stable and efficient. A comparison with closely related palm taxa reveals that V. gerardii is 38-ploid, and comparison with the closely related genera Butia, Cocos (coconut) and Jubaea shows that Voanioala has lost ∼35% of its DNA amount subsequent to polyploidization and has suppressed between 74 and 88% of the original nucleolar organizers. About 10 active NORs are present in the nuclei. An auto- or allopolyploid origin of Voanioala is discussed with respect to currently available nuclear gene data. The biogeographic relations to Jubaeopsis, a closely related, monotypic, apparently likewise relict palm genus from eastern mainland South Africa are discussed. From a cytogenetic point of view, a common polyploid ancestor of both genera is most likely, but the available molecular phylogenetic data are not univocal.


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