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.

Nucleolar competition analysis in Aegilops ventricosa and its amphiploids with tetraploid wheats and diploid rye by the silver-staining procedure

1984 ◽  
Vol 26 (1) ◽  
pp. 34-39 ◽  
Author(s):  
J. Orellana ◽  
J. L. Santos ◽  
J. R. Lacadena ◽  
M. C. Cermeño
Keyword(s):  
Secale Cereale ◽  
Silver Staining ◽  
Triticum Turgidum ◽  
Tetraploid Wheat ◽  
Nucleolar Organizer ◽  
Triticum Dicoccoides ◽  
Staining Procedure ◽  
Nucleolar Organizer Regions ◽  
Aegilops Ventricosa ◽  
Tetraploid Wheats

The nucleolar organizer activity of Aegilops ventricosa and its amphiploids with tetraploid wheats (Triticum turgidum, Triticum dicoccum, and Triticum aethiopicum) and diploid rye (Secale cereale) was analyzed by the silver-staining procedure. Triticum turgidum and Triticum dicoccoides show four Ag-NORs (silver-stained nucleolar organizer regions), in agreement with previous data. Only two Ag-NORs are detected in Ae. ventricosa (genome constitution DDMM) indicating that natural amphiplasty occurs in this allotetraploid species. No amphiplasty was observed in the Ae. ventricosa – tetraploid wheat amphiploids since six Ag-NORs were visible in all of them. On the contrary, only two Ag-NORs were detected in the Ae. ventricosa – Secale cereale amphiploid, the rye NORs being suppressed by the presence of ventricosa chromosomes. The ventricosa NORs therefore are codominant with those of tetraploid wheat (chromosomes 1B and 6B) and dominant to chromosome 1R of rye. Eleven T. aestivum – Ae. ventricosa addition lines have been also analyzed. All of them showed four Ag-NORs. Clear-cut conclusions were not reached since the added ventricosa chromosomes were not identified.

Nucleolar organizer competition in Aegilops–rye hybrids

1985 ◽  
Vol 27 (4) ◽  
pp. 479-483 ◽  
Author(s):  
M. C. Cermeño ◽  
J. R. Lacadena
Keyword(s):  
Secale Cereale ◽  
Silver Staining ◽  
Nucleolar Organizer ◽  
Nucleolus Organizer ◽  
Staining Procedure ◽  
Nucleolar Activity ◽  
Nucleolar Organizer Activity ◽  
Organizer Activity ◽  
Chromosome 1R

The nucleolar organizer activity in several Aegilops × rye hybrids (A. triuncialis × Secale cereale, A. variabilis × S. cereale, A. biunicialis × S. cereale, A. biuncialis × S. vavilovii, A. juvenalis × S. cereale) is analyzed by using a highly reproducible silver-staining procedure. The 1U and 5U chromosomes show a strong nucleolar activity, suppressing the NOR activity of chromosome 1R from rye in all the hybrid combinations (UCR, USvR, UMbR, UMbRv, and UMjDR). The nucleolus organizer chromosomes from the genomes C, Sv, Mb, and Mj show small activities. Our results confirm previous data of the nucleolar organizer activity predominant status of the 1U and 5U chromosomes from the U genome (A. umbellulata) and the weakest condition of the 1R chromosome from rye. A diagram showing the relationships between the nucleolar organizer activities of chromosomes from different genomes of Triticeae is presented.Key words: nucleolar competition, amphiplasty, Ag-NORs, Triticeae, Aegilops, Secale.

Sequential silver staining and in situ hybridization reveal a direct association between rDNA levels and the expression of homologous nucleolar organizing regions: a hypothesis for NOR structure and function

1998 ◽  
Vol 111 (10) ◽  
pp. 1433-1439
Author(s):  
F. Zurita ◽  
R. Jimenez ◽  
M. Burgos ◽  
R.D. de la Guardia
Keyword(s):  
Transcription Factors ◽  
In Situ Hybridization ◽  
Silver Staining ◽  
Organizer Region ◽  
Nucleolar Organizer ◽  
Interindividual Variation ◽  
Nucleolar Organizer Regions ◽  
Single Pair ◽  
Ribosomal Cistrons

We have developed a procedure for sequential silver staining and in situ hybridization to analyze the relationship between the amount of rDNA present in nucleolar organizer regions, as estimated by in situ hybridization, and their level of expression, as estimated by the silver signal. For simplicity we used cells from the insectivorous mole Talpa occidentalis, which have a single pair of nucleolar organizer regions in chromosome pair 3. The relative content of ribosomal cistrons was also related to the hierarchy of activation of the nucleolar organizer regions present in this chromosomal pair. Statistical analyses demonstrated that both the relative level of expression and the activation hierarchy depended mainly on the number of ribosomal cistrons in nucleolar organizer regions. We propose a functional two-step hypothesis, which is consistent with most known data concerning interchromosomal, intercellular and interindividual variation in a number of plant and animal species, including Talpa occidentalis. In step one, the first available transcription factors bind randomly to the ribosomal promoters, such that larger nucleolar organizer regions are more likely to recruit them. In the second step the remaining transcription factors are recruited in a cooperative way, thus completing activation of one nucleolar organizer region, before the next one becomes active.

Nucleolar organizer activity in wheat, rye and derivatives analyzed by a silver-staining procedure

Chromosoma ◽  
1984 ◽  
Vol 89 (5) ◽  
pp. 370-376 ◽  
Author(s):  
M. C. Cerme�o ◽  
J. Orellana ◽  
J. L. Santos ◽  
J. R. Lacadena
Keyword(s):  
Silver Staining ◽  
Nucleolar Organizer ◽  
Staining Procedure ◽  
Nucleolar Organizer Activity ◽  
Organizer Activity

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.

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