scholarly journals First report of karyological analysis and heteromorphic nucleolar organizer region of Black Surgeonfish (Acanthurus gahhm, Acanthuridae) in Thailand

Caryologia ◽  
2021 ◽  
Vol 74 (1) ◽  
pp. 83-88
Author(s):  
Sitthisak Jantarat ◽  
Sarun Jumrusthanasan ◽  
Sarawut Kaewsri ◽  
Praween Supanuam ◽  
Alongklod Tanomtong
Keyword(s):  
Organizer Region ◽  
Nucleolar Organizer Region ◽  
Nucleolar Organizer ◽  
Andaman Sea ◽  
Nucleolar Organizer Regions ◽  
Mitotic Chromosomes ◽  
Karyological Analysis ◽  
First Report ◽  
Telocentric Chromosomes ◽  
Karyotype Formula

This research was the first report on karyological analysis and heteromorphic nucleolar organizer region of black surgeonfish (Acanthurus gahhm, Acanthuridae) in Thailand. The 10 male and 10 female specimens were collected from Phuket Marine Biological Center, and Phang Nga Coastal Research and Development Center, Andaman Sea, Thailand. Mitotic chromosomes were directly prepared from gill and kidney tissues. The chromosomes were stained by conventional Giemsa staining and Ag-NOR banding techniques. Results showed that the diploid chromosomes number of A. gahhm was 2n=48, the fundamental numbers (NF) was 54 in both male and female. The karyotype consist of 6 large acrocentric, 20 large telocentric, 18 medium telocentric and 4 small telocentric chromosomes. None of strange size chromosomes related to sex was found. The heteromorphic nucleolar organizer regions (NORs) were observed on telomeric short arm of first acrocentric which can defined as 1a1b. There is NOR in 1a and not in 1b. The karyotype formula of black surgeon fish was as follows: 2n (48) = La6+Lt20+Mt18+St4

scholarly journals First Report on Nucleolar Organizer Regions (NORs) Polymorphism and Constitutive Heterochromatin of Moonlight Gourami, Trichopodus microlepis (Perciformes, Osphronemidae)

Caryologia ◽  
2021 ◽  
Author(s):  
Weerayuth Supiwong
Keyword(s):  
Chromosome Pair ◽  
Constitutive Heterochromatin ◽  
Sex Chromosome ◽  
Nucleolar Organizer ◽  
Nucleolar Organizer Regions ◽  
Mitotic Chromosomes ◽  
First Report ◽  
Telocentric Chromosomes ◽  
Karyotype Formula ◽  
Males And Females

Nucleolar organizer regions (NORs) polymorphism, constitutive heterochromatin and chromosomal analysis of Moonlight gourami, Trichopodus microlepis in Thailand were firstly reported. Specimens were collected from the Chao Phraya and Mekong Basins, Thailand. The mitotic chromosomes were directly prepared from kidney tissues of ten males and ten females. Conventional staining, Ag-NOR banding and C- banding techniques were applied to stain the chromosomes. The results shown that the diploid chromosome number of T. microlepis was 2n=46 and the fundamental number (NF) was 46 in both males and females. The karyotype consisted of 46 telocentric chromosomes classifying as 14 large and 32 medium. No heteromorphic sex chromosome was observed in T. microlepis. The results also exhibited that the interstitial nucleolar organizer regions (NORs) were clearly observed at the long arm of the chromosome pair 7. This is the first report on NORs polymorphism in T. microlepis that a heteromorphic NOR type in one female had a single NOR-bearing chromosome of the chromosome pair 7, whereas 10 males and nine females had two NOR-bearing chromosomes of the chromosome pair 7 with a homomorphic NOR type. Constitutive heterochromatins located at all centromeres of all chromosome pairs. The karyotype formula of T. microlepis is 2n (46) = Lt14 + Mt32.

Nucleologenesis in Trypanosoma cruzi

2016 ◽  
Vol 22 (3) ◽  
pp. 621-629 ◽  
Author(s):  
Tomás Nepomuceno-Mejía ◽  
Reyna Lara-Martínez ◽  
Roberto Hernández ◽  
María de Lourdes Segura-Valdez ◽  
Luis F. Jiménez-García
Keyword(s):  
Cell Division ◽  
Trypanosoma Cruzi ◽  
Ethylenediaminetetraacetic Acid ◽  
Organizer Region ◽  
Nucleolar Organizer Region ◽  
Light And Electron Microscopy ◽  
Nucleolar Organizer ◽  
Nuclear Bodies ◽  
Nucleolar Organizer Regions ◽  
Nucleolar Material

AbstractNucleolar assembly is a cellular event that requires the synthesis and processing of ribosomal RNA, in addition to the participation of pre-nucleolar bodies (PNBs) at the end of mitosis. In mammals and plants, nucleolar biogenesis has been described in detail, but in unicellular eukaryotes it is a poorly understood process. In this study, we used light and electron microscopy cytochemical techniques to investigate the distribution of nucleolar components in the pathway of nucleolus rebuilding during closed cell division in epimastigotes of Trypanosoma cruzi, the etiologic agent of American trypanosomiasis. Silver impregnation specific for nucleolar organizer regions and an ethylenediaminetetraacetic acid regressive procedure to preferentially stain ribonucleoprotein revealed the conservation and dispersion of nucleolar material throughout the nucleoplasm during cell division. Furthermore, at the end of mitosis, the argyrophilic proteins were concentrated in the nucleolar organizer region. Unexpectedly, accumulation of nucleolar material in the form of PNBs was not visualized. We suggest that formation of the nucleolus in epimastigotes of T. cruzi occurs by a process that does not require the concentration of nucleolar material within intermediate nuclear bodies such as mammalian and plant PNBs.

Number of Nucleoli and Nucleolar Organizer Regions per Nucleus and Nucleolus — Prognostic Value in Canine Mammary Tumors

1996 ◽  
Vol 33 (5) ◽  
pp. 527-532 ◽  
Author(s):  
M. BratuliĆ ◽  
Ž GrabareviĆ ◽  
B. ArtukoviĆ ◽  
D. Capak
Keyword(s):  
Malignant Tumors ◽  
Organizer Region ◽  
Nucleolar Organizer Region ◽  
Nucleolar Organizer ◽  
Staining Technique ◽  
Mammary Tumors ◽  
World Health ◽  
Nucleolar Organizer Regions ◽  
Canine Mammary Tumors ◽  
Significant Difference

Twenty-eight canine mammary tumors were evaluated for histopathologic classification as recommended by the World Health Organization and silver-binding nucleolar organizer region (AgNOR) and nucleolus counts. Samples of surgically excised tumors and tumors taken at necropsy were fixed in neutral formalin, embedded in paraffin, and cut into 1-3-μm-thick sections. Two sections were taken from each tumor: one was stained with hematoxylin and eosin and the other was treated with the silver staining technique for the demonstration of AgNORs. After histopathologic classification, the number of nucleoli and the number of AgNORs/nucleus and AgNORs/nucleolus were determined. Statistical analysis (Student's t-test) showed a significant difference in the mean number of nucleoli ( P < 0.005), mean number of AgNORs/nucleolus ( P < 0.001), and mean number of AgNORs/nucleus ( P < 0.005) between benign and malignant canine mammary tumors. There was no significant differences between metastatic and nonmetastatic malignant tumors.

scholarly journals Silver staining of the nucleolar organizer regions (NORs) on Lowicryl and cryo-ultrathin sections.

1985 ◽  
Vol 33 (5) ◽  
pp. 389-399 ◽  
Author(s):  
F J Moreno ◽  
D Hernandez-Verdun ◽  
C Masson ◽  
M Bouteille
Keyword(s):  
Silver Staining ◽  
Organizer Region ◽  
Nucleolar Organizer Region ◽  
Nucleolar Organizer ◽  
Enzymatic Digestion ◽  
Rnase A ◽  
Micrococcal Nuclease ◽  
Nucleolar Organizer Regions ◽  
Step Procedure ◽  
Ultrathin Sections

Nucleolar organizer region (NOR) silver staining was applied to sections of fixed material. A positive reaction on cryo-ultrathin sections was found as well as on semithin and ultrathin Lowicryl sections. Repeatable staining that was easy to control was obtained by a one-step procedure after aldehyde-Carnoy fixation. Fixation of the material by formaldehyde and glutaraldehyde alone in cacodylate buffer also maintained reaction selectivity when ammonium chloride was used after fixation. Enzymatic digestion by pronase, RNase A, DNase I, or micrococcal nuclease was applied to ultrathin Lowicryl sections. Pronase digestion removed the silver-stained proteins, whereas digestion by the nucleases did not. A routine procedure is proposed for easy NOR silver staining of sections that preserves a good tissue ultrastructure and is also compatible with cytochemical and immunological investigations.

scholarly journals Preliminary investigation on the variation of the nucleolar organizer region in the breeding chinchilla karyotype

2016 ◽  
Vol 72 (6) ◽  
pp. 373-377 ◽  
Author(s):  
Marta Kuchta-Gładysz ◽  
Agnieszka Otwinowska-Mindur ◽  
Piotr Niedbała ◽  
Olga Szeleszczuk ◽  
Joanna Głowacka
Keyword(s):  
Silver Staining ◽  
Organizer Region ◽  
Preliminary Investigation ◽  
Nucleolar Organizer Region ◽  
Nucleolar Organizer ◽  
Nucleolar Organizer Regions ◽  
Silver Deposit ◽  
Nor Polymorphism ◽  
The Mean ◽  
Class Iv

The objective of this study was to determine the variation in the number and size of nucleolar organizer regions (NOR) in the chinchilla karyotype. The study was performed with 12 standard chinchillas of two different lines. NORs were visualized on chromosome preparations by Ag-NOR silver staining. Four NOR size classes (I-IV) were determined on the basis of the results obtained, ranging from 0.070 (class I) to 0.229 (class IV). The mean NOR size was 0.144 µm² (SD=0.031 µm²) and fell within class II (from 0.101 to 0.150 µm²). Differences in the relative silver deposit area between the NOR-bearing pair of chromosomes were significant for 3 animals (P < 0.01) and for 1 animal (P < 0.05). The mean number of NORs in the animals ranged from 1.4 to 2.0 (SD=0.00–0.55). It was lower for chinchillas from central Poland (1.53±0.50) compared to those from southern Poland (1.68±0.48), with no significant differences (P > 0.05). The variation observed in the NOR size and number in the chinchilla karyotype indicates the occurrence of NOR polymorphism in the population.

scholarly journals The Role of Argyrophilic Nucleolar Organizer Region (AgNOR) Study in Cytological Evaluation of Fluids, Especially for Detection of Malignancy

2012 ◽  
Vol 10 (1) ◽  
pp. 34-39 ◽  
Author(s):  
S Karki ◽  
A Jha ◽  
G Sayami
Keyword(s):  
Silver Staining ◽  
Organizer Region ◽  
Nucleolar Organizer Region ◽  
Nucleolar Organizer ◽  
Staining Technique ◽  
Nucleolar Organizer Regions ◽  
Serous Effusion ◽  
Malignant Cells ◽  
Associated Proteins ◽  
Malignant Effusions

Background Serous effusion smears reported as “suspicious for malignancy” pose problems in clinical management. Silver staining for argyrophilic nucleolar organizer regions (AgNOR) has proved useful in making a cytopathologic differential diagnosis between benign and malignant cells. Nucleolar organizer regions(NORs) are loops of DNA located in acrocentric chromosomes. These NORs are visualized by silver staining technique that recognizes these argyrophilia associated proteins which are increased in malignancy. Objective This study aimed to distinguish reactive mesothelial cells from malignant cells in serous effusions using these NORs. Methods A total of 174 serous effusions received at the Department of Pathology, TUTH, during a period of one year were included in the study. Smears were studied by conventional Papanicolaou and Giemsa stains. AgNOR counts, variation in size and dispersion of AgNOR dots in smears were graded and compared in malignant and non-malignant effusions. Results Mean AgNOR counts of 10.43±0.73 and 10.21±0.51 in malignant peritoneal and pleural effusions, respectively, were significantly (p<0.0001) greater as compared with counts of 2.12±0.54 and 2.11±0.54 in non-malignant effusions. The AgNORs were irregular in shape in malignant effusions whereas they were comparatively larger, single dots in benign effusions. AgNOR size and dispersion were of higher grade in significantly greater proportion of malignant as compared with non malignant effusions (p<0.0001). Of the cytologically suspicious samples, nine were in the malignant range and one was in the benign range. Conclusion AgNOR study appears to be clinically useful as an additional diagnostic tool for use in serous effusion when the cytologic diagnosis is difficult. KATHMANDU UNIVERSITY MEDICAL JOURNAL  VOL.10 | NO. 1 | ISSUE 37 | JAN - MAR 2012 | 44-47 DOI: http://dx.doi.org/10.3126/kumj.v10i1.6913

scholarly journals In situ fluorescent visualization of nucleolar organizer region-associated proteins with a thiol reagent.

1993 ◽  
Vol 41 (9) ◽  
pp. 1413-1417 ◽  
Author(s):  
G Méhes ◽  
E Kálmán ◽  
L Pajor
Keyword(s):  
Silver Staining ◽  
Organizer Region ◽  
Nucleolar Organizer Region ◽  
Nucleolar Organizer ◽  
Nucleolar Organizer Regions ◽  
Thiol Reagent ◽  
Sh Group ◽  
Associated Proteins ◽  
Rnase Digestion

Nucleolar organizer regions (NORs) are nucleolus-forming rDNA loops associated with argyrophil proteins, the amount of which varies according to the proliferative state of the cell. It has been presumed that the nucleolar protein-related thiol groups may have a role in selective silver staining. We investigated the nuclear thiol distribution with a fluorescent thiol reagent, coumarinyl-phenyl-maleimide (CPM) in human K-562 myeloblast cultures and found that SH group-related fluorescence was brightest in the area of nucleoli, which became highly selective after RNAse digestion. A remarkable co-localization of AgNOR silver reaction and CPM fluorescence was observed, although occupation of the SH groups by CPM did not prevent the silver staining. We applied the stain to dual-parameter flow cytometry in combination with DNA content measurements, which provide further information on nucleolar function and changes in experimental and pathological specimens.

Quantitative analysis of the variability of nucleolar organizer regions in Salmo trutta

Genome ◽  
1993 ◽  
Vol 36 (6) ◽  
pp. 1119-1123 ◽  
Author(s):  
P. Martínez ◽  
A. Viñas ◽  
C. Bouza ◽  
J. Castro ◽  
L. Sánchez
Keyword(s):  
Quantitative Analysis ◽  
Salmo Trutta ◽  
Chromosome Region ◽  
Organizer Region ◽  
Nucleolar Organizer Region ◽  
Size Variation ◽  
Nucleolar Organizer ◽  
Chromosome Length ◽  
Nucleolar Organizer Regions ◽  
Structural Polymorphism

A quantitative analysis combined with Ag staining was carried out to study the size variation of the main nucleolar organizer region (NOR) bearing chromosome pair 11 of Salmo trutta. A standardized NOR size measurement was developed by comparing the length of the short arm (NOR-bearing region) to the total chromosome length. Statistical procedures support arguments for the existence of a large and structural polymorphism within this species for this chromosome region. A minimum of five different chromosome classes were identified, which account for the total variation found. Size variation among classes was due both to changes in the number of NOR clusters as well as to the amount of rDNA genes within each cluster. NOR size values were normally distributed in the sample analyzed.Key words: nucleolar organizer region, size polymorphism, brown trout.

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