Analysis of nucleolus organizer regions (NORs) in mitotic and polytene chromosomes ofPhaseolus coccineus by silver staining and Giemsa C-banding

1979 ◽  
Vol 132 (1-2) ◽  
pp. 27-51 ◽  
Author(s):  
Dieter Schweizer ◽  
Peter Ambros
Keyword(s):  
Silver Staining ◽  
Polytene Chromosomes ◽  
Nucleolus Organizer ◽  
Nucleolus Organizer Regions ◽  
C Banding

Genetic and cytogenetic analyses of the A genome of Triticum monococcum. VI. Production and identification of primary trisomics using the C-banding technique

Genome ◽  
1990 ◽  
Vol 33 (4) ◽  
pp. 542-555 ◽  
Author(s):  
B. Friebe ◽  
N.-S. Kim ◽  
J. Kuspira ◽  
B. S. Gill
Keyword(s):  
Nucleolus Organizer ◽  
Triticum Monococcum ◽  
Banding Patterns ◽  
Primary Trisomics ◽  
Nucleolus Organizer Regions ◽  
C Banding ◽  
A Genome ◽  
Chromosome 5A ◽  
Triple Dose

Cytogenetic studies in Triticum monococcum (2n = 2x = 14) are nonexistent. To initiate such investigations in this species, a series of primary trisomics was generated from autotriploids derived from crosses between induced autotetraploids and diploids. All trisomics differed phenotypically from their diploid progenitors. Only two of the seven possible primary trisomic types produced distinct morphological features on the basis of which they could be distinguished. The chromosomes in the karyotype were morphologically very similar and could not be unequivocally identified using standard techniques. Therefore, C-banding was used to identify the chromosomes and trisomics of this species. Ag–NOR staining and in situ hybridization, using rDNA probes, were used to substantiate these identifications. A comparison of the C-banding patterns of the chromosomes of T. monococcum with those of the A genome in Triticum aestivum permitted identification of five of its chromosomes, viz., 1A, 2A, 3A, 5A, and 7A. The two remaining chromosomes possessed C-banding patterns that were not equivalent to those of any of the chromosomes in the A genome of the polyploid wheats. When one of these undesignated chromosomes from T. monococcum var. boeoticum was substituted for chromosome 4A of Triticum turgidum, it compensated well phenotypically and therefore genetically for the loss of this chromosome in the recipient species. Because this T. monococcum chromosome appeared to be homoeologous to the group 4 chromosomes of polyploid wheats, it was designated 4A. By the process of elimination the second undesignated chromosome in T. monococcum must be 6A. Analysis of the trisomics obtained led to the following conclusions. (i) Trisomics for chromosome 3A were not found among the trisomic lines analyzed cytologically. (ii) Primary trisomics for chromosomes 2A, 4A, 6A, and 7A were positively identified. (iii) Trisomics for the SAT chromosomes 1A and 5A were positively identified in some cases and not in others because of polymorphism in the telomeric C-band of the short arm of chromosome 1A. (iv) Trisomics for chromosome 7A were identified on the basis of their distinct phenotype, viz., the small narrow heads and small narrow leaves. Because rRNA hybridizes lightly to nucleolus organizer regions on chromosome 1A and heavily to nucleolus organizer regions on chromosome 5A, our results indicate that trisomics in line 50 carry chromosome 1A in triple dose and trisomics in lines 28 and 51 carry chromosome 5A in triplicate. Variable hybridization of the rDNA probe to nucleolus organizer regions on chromosomes in triple dose in lines 7, 20, and 28 precluded the identification of the extra chromosome in these lines. Cytogenetic methods for unequivocally identifying trisomics for chromosomes 1A and 5A are discussed. Thus six of the series of primary trisomics have been identified. Telotrisomic lines are also being produced.Key words: Triticum monococcum, trisomics, C-banding, Ag-NOR staining, in situ hybridization, rDNA probes, plant morphology.

scholarly journals Silver staining of the nucleolus organizer regions (NOR) requires clusters of sulfhydryl groups.

1982 ◽  
Vol 30 (9) ◽  
pp. 908-911 ◽  
Author(s):  
A De Capoa ◽  
M Ferraro ◽  
P Lavia ◽  
F Pelliccia ◽  
A Finazzi-Agrò
Keyword(s):  
Heavy Metals ◽  
Silver Staining ◽  
Reducing Agents ◽  
Nucleolus Organizer ◽  
The Other ◽  
Nuclear Proteins ◽  
Staining Reaction ◽  
Nucleolus Organizer Regions ◽  
High Affinity ◽  
Per Se

Silver stainability of nucleolus organizer regions (NORs) appears to be correlated with the presence of grouped sulfhydryl (SH) side chains of proteins. In fact, heavy metals with high affinity for SH groups, such as Hg and Cu, do prevent the silver staining reaction. Ferricyanide, which is known to oxidize SH to disulfides, also prevents any further reaction with silver. On the other hand, alkali and reducing agents (mercaptoethanol, cyanide) do not affect silver stainability of the NORs. These results show that the silver staining reaction is not related to disulfide or persulfide groups and that alkali-soluble, acidic nuclear proteins per se do not play a major role in this process.

Comparison of silver staining of nucleolus organizer regions in human lymphocytes and fibroblasts

1978 ◽  
Vol 42 (3) ◽  
pp. 291-299 ◽  
Author(s):  
A. -V. Mikelsaar ◽  
H. G. Schwarzacher
Keyword(s):  
Silver Staining ◽  
Human Lymphocytes ◽  
Nucleolus Organizer ◽  
Nucleolus Organizer Regions

Cytogenetic analysis of the paternal sex ratio chromosome of Nasonia vitripennis

Genome ◽  
1993 ◽  
Vol 36 (1) ◽  
pp. 157-161 ◽  
Author(s):  
Kent M. Reed
Keyword(s):  
Sex Ratio ◽  
Silver Staining ◽  
Organizer Region ◽  
Parasitic Wasp ◽  
Nucleolus Organizer Region ◽  
B Chromosome ◽  
Nucleolus Organizer ◽  
Nasonia Vitripennis ◽  
C Banding ◽  
Paternal Sex Ratio

Paternal sex ratio (PSR) is a B chromosome found in the parasitic wasp Nasonia vitripennis. PSR has a unique etiology in that it destroys the paternal chromosomes of fertilized eggs, resulting in the production of all male families. This study examined structural aspects of PSR including size, C-banding, and silver staining. PSR was found to constitute approximately 5.7% of the genome of carrier males. C-banding confirmed the heterochromatic nature of PSR and the data suggest that PSR remains primarily condensed throughout the cell cycle. Examination of prometaphase spermatocytes revealed a secondary constriction on PSR. The constriction, however, did not stain positive for nucleolus organizer activity. During mitosis, PSR and the pericentromeric regions of the A chromosomes displayed a temporal pattern of silver staining, involving dense precipitation of silver prior to metaphase. This reaction is indicative of a protein complex specific to the heterochromatin of these regions. The implications of these findings to the origin of PSR are discussed.Key words: Nasonia vitripennis, paternal sex ratio, B chromosome, nucleolus organizer region, heterochromatin.

Cytological and histochemical studies on the mechanism of the selective silver staining of nucleolus organizer regions (NORs)

1979 ◽  
Vol 60 (1) ◽  
pp. 91-99 ◽  
Author(s):  
J. Olert ◽  
G. Sawatzki ◽  
H. Kling ◽  
J. Gebauer
Keyword(s):  
Silver Staining ◽  
Nucleolus Organizer ◽  
Nucleolus Organizer Regions

A simple two-step procedure for silver staining nucleolus organizer regions in plant chromosomes

1985 ◽  
Vol 27 (2) ◽  
pp. 255-257 ◽  
Author(s):  
Romesh C. Mehra ◽  
Susan Brekrus ◽  
Merlin G. Butler
Keyword(s):  
Vicia Faba ◽  
Allium Cepa ◽  
Silver Staining ◽  
Lens Culinaris ◽  
Nucleolar Organizer ◽  
Nucleolus Organizer ◽  
Staining Procedure ◽  
Nucleolar Organizer Regions ◽  
Nucleolus Organizer Regions ◽  
Plant Chromosomes

Nucleolus organizer regions (NORs) of Allium cepa, Lens culinaris, and Vicia faba chromosomes were stained by a two-step silver staining procedure which is simple and highly reproducible. Polymorphisms are apparent with respect to the size of NORs in the taxa understudy.Key words: nucleolar organizer regions, silver staining, Allium cepa, Lens culinaris, Vicia faba.

scholarly journals Karyotype, C-band and NOR phenotype of Anatolian endemic fish Squalius anatolicus (Bogutskaya, 1997) (Teleostei, Leuciscidae)

2021 ◽  
Vol 38 (3) ◽  
pp. 311-315
Author(s):  
Sevgi Ünal Karakuş ◽  
Muhammet Gaffaroğlu
Keyword(s):  
Chromosome Pair ◽  
Constitutive Heterochromatin ◽  
Nucleolus Organizer ◽  
Submetacentric Chromosome ◽  
Nucleolus Organizer Regions ◽  
C Banding ◽  
Nor Phenotype ◽  
Acrocentric Chromosomes ◽  
Endemic Fish ◽  
Lake Beysehir

The karyotype and distribution of constitutive heterochromatin and nucleolus organizer regions (NORs) of Anatolian leuciscine endemic to Lake Beysehir, Squalius anatolicus (Bogutskaya, 1997) were analyzed respectively using conventional Giemsa-staining, C-banding and Ag-impregnation. Diploid chromosome number was 2n = 50 and karyotype consisted of 7 pairs of metacentric, 13 pairs of submetacentric, 5 pairs of subtelo- to acrocentric chromosomes, NF value equaled 90. Heteromorphic elements indicating sex chromosomes were not detected. C-banding revealed clear pericentromeric constitutive heterochromatin blocks in several chromosomes. Ag-impregnation revealed the size heteromorphism of NORs that covered almost the entire short arms of the middle-sized submetacentric chromosome pair. The karyotype pattern and simple NOR phenotype of S. anatolicus are nearly identical with that found not only in Squalius species analyzed to date but also in many other representatives of the Eurasian leuciscine cyprinids, which indicates remarkable chromosome stasis in this leuciscid lineage.

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