RESUMO
ABSTRACT In this study, we investigated the chromosomes of three species of Sicarius spiders from the Brazilian Caatinga, using classical and molecular cytogenetic techniques. Based on the phylogenetic approach, we also discussed about the variation of diploid number, types of sex chromosome system and changes in the localization of ribosomal genes of Scytodoidea. Sicarius are Synspermiata spiders that together with the genera Loxosceles and Hexophthalma constitute the family Sicariidae. In this group, the available cytogenetic data showed a low diploid number range (2n♂=18 to 2n♂=23) and the presence of only multiple sex chromosome systems (X1X2Y and X1X20). Mitotic metaphase cells exhibited 2n♂=16+X1X2Y for Sicarius cariri and S. ornatus, and 2n♂=18+XY for S. tropicus. In these species, silver impregnation revealed nucleolar organizer region (Ag-NOR) on the terminal region of pair 1. In S. ornatus and S. tropicus, the results obtained with fluorescent in situ hybridization (FISH) using 18S rDNA probe were similar to Ag-NOR, however in S. cariri, the ribosomal sites were localized in the terminal region of the X1 sex chromosome. In this work, we presented the first description of a simple sex chromosome system for Sicariidae, helping to understand how the XY sex chromosome system evolved from the X1X2Y system. Additionally, FISH data incongruous with Ag-NOR indicate that the cytogenetic studies in Sicariidae allow investigating the relation between the karyotype evolution and the distribution and the activity of rDNA genes.
RESUMEN En este estudio, investigamos los cromosomas de tres especies de arañas Sicarius de la Caatinga brasileña, utilizando técnicas de citogenética clásica y molecular. Usando un enfoque filogenético, también discutimos la variación del número diploide, los tipos de sistema cromosómico sexual y los cambios en la localización de los genes ribosómicos en Scytodoidea. Los Sicarius son arañas Synspermiata que, junto con los géneros Loxosceles y Hexophthalma, constituyen a la familia Sicariidae. En este grupo, los datos citogenéticos disponibles mostraron un rango de número diploide bajo (2n♂=18 a 2n♂=23) y únicamente la presencia de sistemas de cromosomas sexuales múltiples (X1X2Y y X1X20). Las células mitóticas en metafase mostraron 2n♂=16+X1X2Y para Sicarius cariri y S. ornatus, y 2n♂=18+XY para S. tropicus. En estas especies, la impregnación de plata reveló la región organizadora nucleolar (Ag-NOR) en la región terminal del par 1. En S. ornatus y S. tropicus, los resultados obtenidos con la hibridación in situ fluorescente (FISH) utilizando la sonda de ADNr 18S fueron similares a los de Ag-NOR, sin embargo, en S. cariri los sitios ribosomales se localizaron en la región terminal del cromosoma sexual X1. En este trabajo, presentamos la primera descripción de un sistema cromosómico sexual simple para Sicariidae, ayudando a entender cómo el sistema cromosómico sexual XY evolucionó a partir del sistema X1X2Y. Además, los datos de FISH incongruentes con Ag-NOR indican que los estudios citogenéticos en Sicariidae permiten investigar la relación entre la evolución del cariotipo y la distribución y la actividad de los genes de ADNr.
RESUMO
A wide range of diploid number of chromosomes and the body size of Channa congeners are useful combination of characters for studying the factors controlling the body size. In this study, the karyological information was superimposed on the evolutionary tree generated by 16S rRNA mitochondrial gene sequences. Here, the metaphase chromosome complements stained with Giemsa, AgNO3 and CMA3 were prepared from six snakehead murrel fish species collected from northeast India. The diploid chromosome numbers and the fundamental arms of C. aurantimaculata (2n = 52, NF = 98), C. gachua (2n = 56, NF = 84), C. marulius (2n = 44, NF = 58), C. orientalis (2n = 52, NF = 74), C. punctata (2n = 32, NF = 60) and C. striata (2n = 40, NF = 48) were calculated by the analysis of metaphase chromosome complements. Both methods of nucleolar organizer region (NOR) localization, silver nitrate and chromomycin A3, revealed NOR pairs of 1, 2, 3, 1, 4 and 3 in C. aurantimaculata, C. gachua, C. marulius, C. orientalis, C. punctata and C. striata, respectively. The subject species showed primitive type of asymmetrical chromosomes, except the C. punctata. The variation in 2n for C. orientalis (2n = 52, 78) and C. gachua (2n = 52, 78, 104) of a complete haploid set indicates the possibility of either ploidy change in . orientalisC and C. gachua, if we consider 2n = 52 or the Robertsonian rearrangements in different populations of these two species. The chromosome evolution tree was constructed on 16S rRNA ML-phylogenetic tree using ChromEvol 1.3. The analysis of chromosome evolution explained the loss or gain of chromosome, duplications or semiduplications mechanism. For time scaling the chromosomeevolution, the node age of available 16S rRNA gene of Channa species were estimated, which was also used for estimating the time when chromosomal changes occurred in context of geological time-scale.
RESUMO
OBJECTIVE: Nucleolar organizer regions are loops of DNA containing ribosomal RNA genes and presumably are associated with ribosomal RNA activity, protein synthesis, and cell proliferation. Argyrophilic nucleolar organizer region (AgNOR) count has been suggested as an objective method in differentiating dysplastic lesions from non‑dysplastic lesions. MATERIALS AND METHODS: This descriptive study was done on archival paraffin blocks (n = 60), consisting of 10 normal human oral epithelium, 22 cases of non‑dysplastic leukoplakia (NDLK), and 28 cases of dysplastic leukoplakia (DLK). The AgNORs were counted with the aid of a manual using conventional light microscopy and photographs of the same were taken and analyzed using Image Pro Express 6.0 (Media Cybernetic Inc., USA) for windows. RESULTS: The mean AgNOR count per nucleus was found to be higher in patients with DLK as compared to NDLK and controls using both manual counting and image analysis method and on comparing both the techniques, image analysis provide a more accurate reflection of AgNOR counts than manual counting. CONCLUSION: To conclude, reliability of computerized image technique of AgNOR count is the most appropriate marker to differentiate between dysplastic and NDLK. Computer‑assisted image analysis system was found to be an effective tool in achieving high reproducibility as compare to manual.
RESUMO
Theridiidae is a derived family within the Araneoidea clade. In contrast to closely related groups, the 2n(male) = 20+X1X2 with acro/telocentric chromosomes is the most widespread karyotype among the theridiid spiders. In this work, the cytogenetic analysis of Argyrodes elevatus revealed original chromosome features different from those previously registered for Theridiidae, including the presence of 2n(male) = 20+X with meta/submetacentric chromosomes. Most individuals of Nesticodes rufipes showed family conserved karyotype characteristics. However, one individual had a 2n(male) = 24 due to the presence of an extra chromosome pair, which exhibited regular behavior and reductional segregation during meiosis. After silver staining, mitotic cells exhibited NORs localized on the terminal regions of the short arms of pairs 2, 3, and 4 of A. elevatus and on the terminal regions of long arms of pair 4 of N. rufipes. The comparative analysis with data from phylogenetically related species allowed the clarification of the origin of the interspecific and intraspecific chromosome variability observed in Argyrodes and in N. rufipes, respectively.
RESUMO
Chromatin organization in the holocentric chromosomes of three triatomines species was cytologically studied by fluorescent in situ hybridization with a 45S rDNA probe of Drosophila melanogaster to localize ribosomal genes. In Triatoma tibiamaculata, metaphases I showed telomeric highlights in a single, larger bivalent. In T. protacta, hybridization was detected in one of the telomeres of an autosomal chromosome. In T. platensis, there were highlights in a single, smaller chromosome (X chromosome). The results obtained did not agree with the expected localization of rDNA genes in the sex chromosomes of triatomines, as demonstrated by silver impregnation, and suggest that the chromosome reorganization that occurred in this group during evolution may be a more important mechanism involved in rDNA distribution.
Assuntos
Animais , Masculino , Cromossomos/genética , DNA Ribossômico/análise , Triatominae/genética , Hibridização in Situ Fluorescente , Bandeamento Cromossômico , DNA Ribossômico/genética , Especificidade da Espécie , Fatores do Domínio POU , Metáfase , Proteínas de Drosophila , Proteínas de Homeodomínio , Região Organizadora do Nucléolo , Triatominae/classificaçãoRESUMO
OBJECTIVE: The accurate evaluation of a marker chromosome has been limited during prenatal karyotyping. We proposed a method of step-by-step approach to evaluate the origin of a marker chromosome. METHODS: A patient with 19 weeks of gestation was transferred to our hospital for karyotyping due to abnormal Triple test. Karyotyping of amniotic fluid was performed. NOR (nucleolar organizer region) banding and FISH (fluorescence in situ hybridization) using two types of sex chromosome probes: chromosome X alpha satellite probe (DXZI) & chromosome Y alpha satellite probe (DYZ3)(Cytocell, Bambury, UK) and CEP X/Y (Xp11.1-q11.1 CEP X alpha satellite & Yq12 CEP Y satellite III)(Vysis, IL, USA) were done. RESULTS: The routine chromosomal analysis showed 46,X,+mar. As the result of NOR banding, we supposed that the marker chromosome was less likely originated from acrocentric chromosomes. FISH analysis revealed Y centromere signal on marker chromosome, but Yq12 signal was not detected. Therefore the marker chromosome was identified as Y chromosome formed by deletion at Yq11.2. CONCLUSION: This study demonstrated that FISH and NOR banding technique is more effective method for a marker chromosome evaluation during prenatal karyotyping.
Assuntos
Feminino , Humanos , Gravidez , Líquido Amniótico , Centrômero , Citogenética , Fluorescência , Hibridização In Situ , Cariotipagem , Diagnóstico Pré-Natal , Cromossomos Sexuais , Cromossomo YRESUMO
s Objective:To study the expression of nucleolar orga ni zer region associated protein (Ag NORs) of T lymphocytes in the patients with tumor of salivary gland. Methods:The expression of Ag NORs of T lymphocytes in 60 normal adults, 56 patients with benign salivary gla nd tumor and 45 patients with malignant salivary gland tumor was analysed by Ag stainning and KL imaging system. Results: The ratio of Ag NORs positive area to nuclear area of T lymphocytes in normal adults,pati ents with benign tumor and those with malignant tumor were 7.88?0.10, 5.71?0.1 3 and 4.21?0.12 respectively ( P
RESUMO
BACKGROUND: Nucleolar organizer regions(NORs) are chromosomal segments encoding for ribosomal RNA and associated with argyrophilic nonhistone protein. Ribosomal RNA genes ultimately direct ribosome and protein synthesis, and it has been suggested the numbers of NORs detected in the cell may reflect nuclear and cellular activity. This study was performed to evaluate the applicability of AgNORs to the diagnosis of squamous cell carcinoma of the lung. METHOD: The one step silver methods(AgNORs) was used to stain NORs in the routinely processed, formalin fixed, paraffin embedded sections of 36 cases of squamous cell carcinoma of the lung obtained by surgical resection of primary tumor. In each specimen, 100 tumor cells and 100 normal cells adjacent to the tumor chosen at random were examined under an oil immersion lens at a magnification of X1000. The mean number of AgNORs per nucleus was calculated for each specimen. RESULTS: The mean number of AgNORs per nucleus(mAgNORs) of normal bronchial epithelium and squamous cell carcinoma of the lung was 1.74+/-0.25 and 4.05+/-0.80, respectively. The difference of mAgNOR between normal and tumor tissue was statistically significant(p<0.001). There was no statistical difference among tumors of different stages. The difference of mAgNOR between normal and tumor tissue was statistically significant in each TNM stage(p<0.05). CONCLUSION: Mean AgNOR count may be used as a useful marker for the differential diagnosis of benignancy and malignancy, and proliferative activity of the cell in squamous cell carcinoma of the lung. But there was no statistical difference in mean AgNOR count among tumors of different surgical stages. Further studies for the application of mAgNORs to the diagnosis of other histologic types and cytologic specimens of the lung cancer are needed.
Assuntos
Carcinoma de Células Escamosas , Diagnóstico , Diagnóstico Diferencial , Epitélio , Formaldeído , Genes de RNAr , Imersão , Neoplasias Pulmonares , Pulmão , Região Organizadora do Nucléolo , Parafina , Ribossomos , RNA Ribossômico , PrataRESUMO
The prognosis of transitional cell carcinoma(TCC) of the urinary bladder is related to histopathologic parameters, among which the clinical stage and histopathologic grade are most important prognostic determiantors. Recently the immunohistochemical assessment of proliferating cell nuclear antigen(PCNA) and nucleolar organizer region number(AgNORs) can obtain the PCNA, and AgNORs stainings were studied in 55 the sequential biopsies of 22 recurrent TCCs of the urinary bladder. 6 cases showed the increased changes of grade, of which 5 cases was independently to the change of grade. The AgNORs in 18 cases showed increase in 10 cases. The comparison between PCNA count and AgNORs score according to grade was performed in the changes between grade II and III, both PCNA count and AgNORs score were increased with in crease of grade. However, The change of the PCNA count was stastically significant, but not AgNORs score.
Assuntos
BiópsiaRESUMO
0.05). There was no difference between various historical types neither. But it was found that there was a trend that AgNOR counts would increase as the increase of the historical grade and there was a significant difference (P