Chromosome Studies of Astyanax jacuhiensis Cope, 1894 (Characidae) from the Tramandai River Basin, Brazil, Using in situ Hybridization with the 18S rDNA Probe, DAPI and CMA3 Staining

2012 ◽  
Vol 60 (3) ◽  
pp. 135-140 ◽  
Author(s):  
Laura Lahr Lourenço da Silva ◽  
Lucia Giuliano-Caetano ◽  
Ana Lúcia Dias
2010 ◽  
Vol 8 (3) ◽  
pp. 667-671 ◽  
Author(s):  
Rosiley B. Pacheco ◽  
Lucia Giuliano-Caetano ◽  
Horácio F. Julio Junior ◽  
Ana L. Dias

Cytogenetic analyses were performed in Astyanax jacuhiensis from lago Guaíba, Brazil. The diploid number was 50, with a karyotype composed of 8m+30sm+4st+8a chromosomes, FN = 92. The AgNORs were observed in 2 to 5 chromosomes, with intra- and interindividual variation. The sm pair 8 observed always carried NORs on the short arms, presenting size heteromorphism between homologous. Fluorescence in situ hybridization (FISH) with an 18S rDNA probe only confirmed the location of ribosomal cistrons in the sm pair 8, and heteromorphism of these regions between the homologous chromosomes. C-banding revealed the occurrence of weak C-positive heterochromatin in the pericentromeric regions of several chromosomes, in addition to more evident bands interstitially located on some chromosome pairs and in the terminal region of the short arms in pair 8. C-banding plus CMA3 revealed light fluorescent signals in different chromosomes of the karyotype, with a strong terminal site in pair 8, indicating the occurrence of several GC-rich heterochromatic regions in this species. Our results provide the first description of the Astyanax jacuhiensis karyotype, showing karyotype similarities when compared to various populations of A. altiparanae and A. bimaculatus, indicating that chromosomal features are very similar for these three species.


Genome ◽  
1999 ◽  
Vol 42 (2) ◽  
pp. 274-281 ◽  
Author(s):  
Susan E Brown ◽  
Janice L Stephens ◽  
Nora LV Lapitan ◽  
Dennis L Knudson

Barley metaphase chromosomes (2n = 14) can be identified by fluorescence in situ hybridization (FISH) and digital imaging microscopy using heterologous 18S rDNA and 5S rDNA probe sequences. When these sequences are used together, FISH landmark signals were seen so that all 7 chromosomes were uniquely identified and unambiguously oriented. The chromosomal location of the landmark signals was determined by FISH to a barley trisomic series using the 18S and 5S probes labeled with different fluorophores. The utility of these FISH landmarks for barley physical mapping was also demonstrated when an Amy-2 cDNA clone and a BAC clone were hybridized with the FISH landmark probes.Key words: Hordeum vulgare, barley, FISH, 5S, 18S, rDNA, landmarks, chromosome.


2016 ◽  
Vol 148 (2-3) ◽  
pp. 227-236 ◽  
Author(s):  
Hana Svojanovská ◽  
Petr Nguyen ◽  
Matyáš Hiřman ◽  
Ivan H. Tuf ◽  
Rodzay Abdul Wahab ◽  
...  

The morphologically uniform suborder Cyphophthalmi represents a basal group of harvestmen (Opiliones). As such, it plays an important role in the reconstruction of the karyotype evolution within this arachnid order. The cytogenetic analysis of 6 representatives of the suborder Cyphophthalmi, namely Miopsalis sp. (2n = 30; Stylocellidae), Austropurcellia arcticosa (Cantrell, 1980) (2n = 30; Pettalidae), Parapurcellia amatola de Bivort & Giribet, 2010 (2n = 32; Pettalidae), Paramiopsalis aff. ramulosus Juberthie, 1962 (2n = 28; Sironidae), Cyphophthalmus duricorius Joseph, 1868 (2n = 24; Sironidae), and Siro carpaticus Rafalski, 1956 (2n = 52; Sironidae) was performed. Fluorescence in situ hybridization with 18S rDNA probe was used to analyze the distribution of major ribosomal RNA genes in harvestmen. We confront the obtained cytogenetic data with current hypotheses on cyphophthalmid phylogeny to reconstruct their karyotype evolution. We conclude that the ancestral karyotype of harvestmen consisted of 2n = 30 elements with 1 chromosome pair bearing terminal rDNA clusters. The rDNA locus was multiplicated in the evolution of Cyphophthalmi. However, decreases as well as increases in the number of chromosomes have been detected in the karyotype evolution of Cyphophthalmi. Our data thus reveal unexpected diversity in cyphophthalmid karyotypes.


2006 ◽  
Vol 66 (1b) ◽  
pp. 191-198 ◽  
Author(s):  
R. F. Artoni ◽  
M. L. Terêncio ◽  
M. R. Vicari ◽  
M. C. A. Matiello ◽  
M. M. Cestari ◽  
...  

Karyotypic data are presented for two sympatric Corydoras species of the Lagoa Dourada, namely, C. ehrhadti and C. paleatus, which are found in the upper Tibagi river basin (Ponta Grossa, State of Paraná, Brazil). The same diploid number and karyotypic formula were observed in both species/populations. A great similarity in the constitutive heterochromatin distribution and in the activity of nucleolar organizer regions was also found. The use of in situ hybridization with a fluorescent 18S rDNA probe allowed for the identification of the species/populations through the location of ribosomal sites.


Genetica ◽  
2005 ◽  
Vol 125 (2-3) ◽  
pp. 125-132 ◽  
Author(s):  
Marisa Fagundes Carvalho de Azevedo ◽  
Claudio Oliveira ◽  
Belén G. Pardo ◽  
Paulino Martínez ◽  
Fausto Foresti

2020 ◽  
Vol 14 (4) ◽  
pp. 577-588
Author(s):  
Jaqueline Fernanda Dionísio ◽  
Joana Neres da Cruz Baldissera ◽  
Angélica Nunes Tiepo ◽  
José Antônio Marin Fernandes ◽  
Daniel Ricardo Sosa-Gómez ◽  
...  

In this paper, we present new cytogenetic data for three species of the family Pentatomidae: Dichelops melacanthus (Dallas, 1851), Loxa viridis (Palisot de Beauvois, 1805), and Edessa collaris (Dallas, 1851). All studied species presented holocentric chromosomes and inverted meiosis for the sex chromosomes. D. melacanthus has 2n = 12 (10A + XY); L. viridis showed 2n = 14 (12A + XY); and E. collaris showed 2n = 14 (12A + XY). C-banding was performed for the first time in these species and revealed terminal and interstitial heterochromatic regions on the autosomes; DAPI/CMA3 staining showed different fluorescent patterns. In all species, fluorescence in situ hybridization (FISH) with 18S rDNA probe identified signals on one autosomal bivalent, this being the first report of FISH application in the species D. melacanthus and L. viridis. The results obtained add to those already existing in the literature, enabling a better understanding of the meiotic behavior of these insects.


2020 ◽  
Vol 14 (4) ◽  
pp. 577-588
Author(s):  
Jaqueline Fernanda Dionísio ◽  
Joana Neres da Cruz Baldissera ◽  
Angélica Nunes Tiepo ◽  
José Antônio Marin Fernandes ◽  
Daniel Ricardo Sosa-Gómez ◽  
...  

In this paper, we present new cytogenetic data for three species of the family Pentatomidae: Dichelops melacanthus (Dallas, 1851), Loxa viridis (Palisot de Beauvois, 1805), and Edessa collaris (Dallas, 1851). All studied species presented holocentric chromosomes and inverted meiosis for the sex chromosomes. D. melacanthus has 2n = 12 (10A + XY); L. viridis showed 2n = 14 (12A + XY); and E. collaris showed 2n = 14 (12A + XY). C-banding was performed for the first time in these species and revealed terminal and interstitial heterochromatic regions on the autosomes; DAPI/CMA3 staining showed different fluorescent patterns. In all species, fluorescence in situ hybridization (FISH) with 18S rDNA probe identified signals on one autosomal bivalent, this being the first report of FISH application in the species D. melacanthus and L. viridis. The results obtained add to those already existing in the literature, enabling a better understanding of the meiotic behavior of these insects.


Sign in / Sign up

Export Citation Format

Share Document