High-resolution idiogram of Giemsa R-banded human prophase chromosomes

The schematic representation of RHG-banded chromosomes (R-banding was produced by heat denaturation followed by Giemsa staining (RHG)) in the 850-band range per haploid set, was prepared showing the relative position, the specific size, and the characteristic staining intensity for each band. To this idiogram was adapted the new International Standard Cytogenetic Nomenclature. Our aim was to produce a realisitic idiogram which could help in the preparation of R-banded prophase karyotypes and in the localization of chromosomal rearrangements. A comparative analysis of bands at prophase and metaphase revealed certain aspects of the dynamics involved in chromosome condensation and in R-band organization. The effect of chromosome elongation on the appearance of R-bands within heterochromatic regions has also been discussed.

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Analysis of high-resolution R-bands, obtained by heat-denaturation and Giemsa staining, on human prophase chromosomes

Canadian Journal of Genetics and Cytology ◽

10.1139/g85-014 ◽

1985 ◽

Vol 27 (1) ◽

pp. 83-91 ◽

Cited By ~ 7

Author(s):

R. Drouin ◽

C. L. Richer

Keyword(s):

High Resolution ◽

Banding Pattern ◽

Giemsa Staining ◽

Heat Denaturation ◽

Banding Patterns ◽

International Standard

RHG-bands (heat-denatured Giemsa R-bands) of human prophase chromosomes were analyzed at high resolution, and the banding patterns at prophase and metaphase are presented. The bands were compared with those of the International Standard Cytogenetic Nomenclature idiograms and of the G-band idiograms proposed by J. J. Yunis. The number, size, and position of the RHG-bands correspond rather well with their equivalent G-negative bands, but some differences were noted in the zones of preferential stretching, the juxtacentromeric regions, and the telomeres. Variations in the centromere index and the banding pattern in heterochromatin were also discussed.Key words: human prophase chromosomes, RHG-bands, high-resolution chromosomes.

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High-resolution R-banding at the 1250-band level. II. Schematic representation and nomenclature of human RBG-banded chromosomes

Genome ◽

10.1139/g89-466 ◽

1989 ◽

Vol 32 (3) ◽

pp. 425-439 ◽

Cited By ~ 14

Author(s):

Régen Drouin ◽

Claude-Lise Richer

Keyword(s):

High Resolution ◽

Banding Pattern ◽

Chromosome Banding ◽

Chromosomal Rearrangements ◽

Staining Intensity ◽

Brdu Incorporation ◽

Lateral Asymmetry ◽

Schematic Representation ◽

Band Contrast ◽

Definition Of

Detailed characterization of the RBG-banding pattern at the 1250-band level has been done after thymidine synchronization and block release with 5-bromo-2′-deoxyuridine (BrdU), which induces chromosome elongation and improves definition of chromosomal bands. Optimal conditions for the incorporation of BrdU and the use of the FPG (fluorochrome–photolysis–Giemsa) technique produced excellent band separation and band contrast even in highly elongated prophase chromosomes. Moreover, we did not observe lateral asymmetry in C-banded regions. The schematic representation of these elongated chromosomes in the 1250-band range per haploid set was prepared showing the relative position, the specific size, and the characteristic staining intensity for each band. To this idiogram was extended the International Standard Cytogenetic Nomenclature. This realistic idiogram should help in the preparation of R-banded prophase karyotypes and in the identification and localization of chromosomal rearrangements. Because differences exist between RBG and RHG bands, a brief comparative description of each RBG-banded chromosome is included. Moreover, a minute analysis of the banding pattern revealed that various parts of chromosomes contract differently. We also observed the presence of R-positive bands in heterochromatic regions of the short arms of the acrocentrics, and of chromosomes 1, 9, 16, and Y.Key words: high-resolution chromosome banding, R-banding, idiogram, dynamic bandings, prophase chromosomes, chromosome banding by BrdU incorporation.

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