Karyotype analysis, nucleolus organizer regions and C-banding pattern of Eisenia foetida (oligochaeta, lumbricidae)

Genetica ◽  
1991 ◽  
Vol 83 (2) ◽  
pp. 159-165 ◽  
Author(s):  
R. Vitturi ◽  
D. Colombera ◽  
E. Catalano ◽  
F. P. Amico
Keyword(s):  
Banding Pattern ◽  
Karyotype Analysis ◽  
Nucleolus Organizer ◽  
Eisenia Foetida ◽  
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 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.

scholarly journals Comparative cytogenetics of the ground frogs Eupsophus emiliopugini Formas, 1989 and E. vertebralis Grandison, 1961 (Alsodidae) with comments on their inter- and intraspecific chromosome differentiation

2020 ◽  
Vol 14 (1) ◽  
pp. 61-74
Author(s):  
Camila A. Quercia ◽  
Elkin Y. Suárez-Villota ◽  
Fausto Foresti ◽  
José J. Nuñez
Keyword(s):  
Gene Dosage ◽  
Chromosomal Rearrangements ◽  
Nucleolus Organizer ◽  
Rrna Gene ◽  
Comparative Cytogenetics ◽  
Nucleolar Dominance ◽  
Nucleolus Organizer Regions ◽  
C Banding ◽  
Chromosome Staining ◽  
Dominance Pattern

South American frogs of the genus Eupsophus Fitzinger, 1843 comprise 10 species. Two of them, Eupsophus vertebralis Grandison, 1961 and E. emiliopugini Formas, 1989 belong to the Eupsophus vertebralis group, exhibiting 2n = 28. Fundamental number differences between these species have been described using conventional chromosome staining of few specimens from only two localities. Here, classical techniques (Giemsa, C-banding, CMA3/DAPI banding, and Ag-NOR staining), and fluorescence in situ hybridization (FISH, with telomeric and 28S ribosomal probes), were applied on individuals of both species collected from 15 localities. We corroborate differences in fundamental numbers (FN) between E. vertebralis and E. emiliopugini through Giemsa staining and C-banding (FN = 54 and 56, respectively). No interstitial fluorescent signals, but clearly stained telomeric regions were detected by FISH using telomeric probe over spreads from both species. FISH with 28S rDNA probes and Ag-NOR staining confirmed the active nucleolus organizer regions signal on pair 5 for both species. Nevertheless, one E. emiliopugini individual from the Puyehue locality exhibited 28S ribosomal signals on pairs 4 and 5. Interestingly, only one chromosome of each pair showed Ag-NOR positive signals, showing a nucleolar dominance pattern. Chromosomal rearrangements, rRNA gene dosage control, mobile NORs elements, and/or species hybridization process could be involved in this interpopulation chromosomal variation.

scholarly journals IDENTIFIKASI KROMOSOM HOMOLOG MELALUI DETEKSI NUCLEOLUS ORGANIZER REGIONS DENGAN PEWARNAAN AgNO3 PADA TANAMAN BAWANG MERAH - IN PRESS -

2020 ◽  
Vol 7 (1) ◽  
Author(s):  
Andin Puspita ◽  
Agus Budi Setiawan ◽  
Aziz Purwantoro ◽  
Endang Sulistyaningsih
Keyword(s):  
Chromosome Number ◽  
Chromosome Pair ◽  
Karyotype Analysis ◽  
Standard Procedure ◽  
Nucleolus Organizer ◽  
Specific Probe ◽  
Homologous Chromosomes ◽  
Nucleolus Organizer Regions ◽  
Carnoy’S Solution ◽  
Precise Identification

Generally, the standard procedure for karyotype analysis of shallot is sorted by chromosome sizes. Therefore, the identification of homologous chromosomes is difficult without using a specific probe. Nucleolus Organizing Regions (NORs) can be used as a probe for precise identification of homologous chromosomes. However, the use of NORs for plant karyotyping in Indonesia is poorly investigated. In this study, shallot chromosomes were prepared using modified Carnoy’s solution II, fixed in Carnoy’s solution, and stained by using aceto-carmine and AgNO3 for detecting NORs. Chromosome images were analyzed by CHIAS IV. One locus NOR bearing chromosome pair was detected at metaphase and interphase, and it was located at short arms of subtelomeric chromosome number 6. NORs can be used as a probe for precise identification of homologous chromosomes in shallot. Therefore, this technique has the potential to be applied on species closely related to shallot and on other plant species.Keywords: AgNO3, chromosome condensation, NORs, shallot chromosome, shallot karyotype ABSTRAKProsedur kariotipe untuk bawang merah umumnya masih disusun berdasarkan ukuran kromosom, sehingga diperlukan suatu penanda yang dapat mengidentifikasi kromosom homolog secara presisi. Identifikasi kromosom homolog secara presisi menggunakan suatu penanda, khususnya deteksi Nucleolus Organizing Regions (NORs), yang di Indonesia masih jarang dilakukan. Penelitian ini bertujuan untuk membuat kariotipe dan mengidentifikasi kromosom homolog bawang merah melalui deteksi NORs menggunakan metode pewarnaan AgNO3. Proses fiksasi akar dilakukan dengan menggunakan modifikasi larutan Carnoy II, lalu difiksasi dengan larutan Carnoy, dan kromosom diwarnai dengan aceto-carmine dan larutan AgNO3 untuk mendeteksi NORs. Selanjutnya, citra kromosom dianalisis menggunakan CHIAS IV. Hasil penelitian menunjukkan bahwa terdapat sepasang NORs yang terdeteksi pada fase metafase dan interfase yang  terletak pada bagian lengan pendek di kromosom subtelosentrik nomor 6. Hasil dari penelitian ini dapat dijadikan sebagai dasar di bidang sitogenetika bawang merah untuk mengidentifikasi kromosom homolog secara presisi menggunakan penanda NOR. Oleh karenanya, teknik ini dapat diaplikasikan pada spesies yang berdekatan dengan bawang merah dan komoditas tanaman lainnya.Kata Kunci: AgNO3, kariotipe bawang, kondensasi kromosom, kromosom bawang, NORs

Somatic cell cytology of the chromosome-eliminating, intergeneric hybrid Hordeum vulgare × Psathyrostachys fragilis

1984 ◽  
Vol 26 (4) ◽  
pp. 436-444 ◽  
Author(s):  
I. Linde-Laursen ◽  
R. von Bothmer
Keyword(s):  
Hordeum Vulgare ◽  
Metaphase Plate ◽  
Intergeneric Hybrid ◽  
Chromosome Elimination ◽  
Staining Intensity ◽  
Nucleolus Organizer ◽  
Common Mechanism ◽  
Banding Patterns ◽  
Nucleolus Organizer Regions ◽  
C Banding

In the hybrid Hordeum vulgare × Psathyrostachys fragilis the two genomes were differentiated (i) by length, the P. fragilis chromosomes being 31% longer than the H. vulgare chromosomes; (ii) by a difference in staining intensity of C-banded chromosomes (of possible use for exact localization of breakpoints), the H. vulgare chromosomes being the more heavily stained; (iii) by widely different C-banding patterns; and (iv) by the difference between N-banded H. vulgare and non-N-banded P. fragilis chromosomes. Only C-banding patterns identified each chromosome. Aneuploid cells had lost between one and five P. fragilis chromosomes. Loss of H. vulgare chromosomes is ascribed to squashing. No haploid H. vulgare cell was observed. The P. fragilis chromosomes were characterized by diminished centric constrictions, suppression of nucleolar constrictions, and nucleolus activity, i.e., differential amphiplasty, and generally a peripheral location on the metaphase plate. The same characteristics are normally observed in hybrids producing haploids H. vulgare, suggesting a common mechanism of chromosome elimination. Some cells had a side-by-side arrangement of genomes. The only effect of the hybrid condition on H. vulgare chromosomes was the formation of wider nucleolar constrictions and larger nucleolus organizer regions (NORs) than in parental H. vulgare, suggesting a compensational mechanism for nucleolus activity. The passage of H. vulgare chromosomes through the hybrid to the dihaploid did not influence chromosomal characteristics.Key words: Hordeum, Psathyrostachys, hybrids, elimination of chromosomes, banding.

Chromosomal Instability and Origin of B Chromosomes in the Amazonian Glass Tetra Moenkhausia oligolepis (Günther, 1864) (Characiformes, Characidae)

2021 ◽  
pp. 249-256
Author(s):  
Luana Pereira dos Santos ◽  
Carine M. Francisco ◽  
Edimar O. Campos Júnior ◽  
Jonathan P. Castro ◽  
Ricardo Utsunomia ◽  
...  
Keyword(s):  
Chromosomal Instability ◽  
Diploid Number ◽  
Karyotype Analysis ◽  
Pericentromeric Region ◽  
Nucleolus Organizer ◽  
B Chromosomes ◽  
Interindividual Variation ◽  
Nucleolus Organizer Regions ◽  
Karyotypic Formula ◽  
Whole Chromosome Painting

B chromosomes occur in different species of the small characid fishes of the genus <i>Moenkhausia.</i> These supernumerary elements, that do not recombine with chromosomes of the standard A complement and follow their own evolutionary mechanism vary in number, morphology, and distribution. Here, we show karyotypic data of individuals of 2 populations of <i>Moenkhausia oligolepis</i> of the Brazilian Amazon (Pedro Correia and Taboquinha streams, Tocantins river basin), both with a diploid number of 50 chromosomes and karyotypic formula of 10m + 32sm + 8a. In addition to the normal complement, we also observed the occurrence of B chromosomes in the 2 populations with intra- and interindividual variation ranging from 0 to 10 Bs, independent of sex. The C-banding pattern evidenced heterochromatic blocks located mainly in the pericentromeric region of the chromosomes, while the B chromosomes appeared euchromatic. Silver-stained nucleolus organizer regions were identified in multiples sites, and some of these blocks were positive when stained with chromomycin A<sub>3.</sub> The karyotype analysis and the application of whole-chromosome painting in populations of <i>M. oligolepis</i> reinforce the conservation of the basal diploid number for the genus, as well as the evolutionary tendency in these fishes to carry B chromosomes. Both populations turned out to be in different stages of stability and expansion of their B chromosomes. We further suggest that the origin of these chromosomes is due to the formation of isochromosomes. Here, we identified a pair of complement A chromosomes involved in this process.

Sign in / Sign up

Export Citation Format

Share Document