Full-text resources of PSJD and other databases are now available in the new Library of Science.
Visit https://bibliotekanauki.pl
Preferences help
Polish version English version Language
enabled [disable] Abstract
Number of results

Results found: 3

Number of results on page
first rewind previous Page / 1 next fast forward last

Search results

help Sort By:

help Limit search:
first rewind previous Page / 1 next fast forward last
1

Analyses of the structure of NORs in two species of south American Sorubiminae fishes (Siluriformes) by means of several cytogenetic techniques

100%
Swarca A. C., Fenocchio A. S., Cestari M. M., Dias A. L.
Folia Biologica
|
2008
|
vol. 56
|
issue 1-2
31-35
EN
Several cytogenetic techniques (AgNOR, C- G- and RE bandings, DAPI, CMA3 and FISH) were applied in order to analyze the structure and variability of NORs in the fish species Steindachneridion melanodermatum and S. scripta. Ag-NORs were observed on the short arm of the first acrocentric chromosome pair, coincidentally with a strong C-positive band on a large secondary constriction. In addition, NORs showed bright fluorescent signals when stained with CMA3 and treated for FISH with rDNA 18S. However, they showed negative coloration after G- and restriction enzyme banding and DAPI staining. The results evidence a substantial size polymorphism in these regions. The NOR bearing chromosomes in both species may be considered homologues because they maintain conserved characteristics, such as being interspersed with a GC-rich heterochromatin and possessing target sequences for AluI, BamHI and EcoRI.
2

Characterization of the constitutive heterochromatin of Astyanax sp. D (Characiformes: Characidae) from the UPPER Iguacu River (PR)

100%
Kantek D. L. Z., Cestari M. M., Bertollo L. A. C., Moreira-Filho O.
Folia Biologica
|
2009
|
vol. 57
|
issue 1-2
37-41
EN
Chromosomal characterization of constitutive heterochromatin was performed in Astyanax sp. D, a species found in the Igua?u river, using C-banding, fluorescent in situ hybridization (FISH) of the repetitive DNA family As51, localization of the 18S rDNA sites and base-specific fluorochromes. The sites of the satellite DNA coincide with large heterochromatic blocks present in this species, namely CMA3- and DAPI-. The many 18S rDNA sites are CMA3+. Similarity between the large heterochromatic blocks is suggested, as well as the identification of two types of heterochromatin, one related to the 18S rDNA domains and the other to the As51 regions.
3

Karyotypic characterization and NOR analysis by different banding techniques of Rhamdia quelen from the first plateau of the Iguacu River (Brazil)

100%
Fenocchio A. S., Swarca A. C., Cestari M. M., Dias A. L.
Folia Biologica
|
2003
|
vol. 51
|
issue 3-4
219-222
EN
A population of R. quelen from the first plateau of the Iguacu River (Parana State, Brazil) was analyzed cytogenetically. A diploid set of 58 chromosomes was constituted by 32 M, 16 SM, 6 ST and 4 A (FN=116). In one individual a 2n=59 karyotype was determined due to the presence of one additional metacentric heterochromatic chromosome. NORs, detected by AgNO3 and CMA3 staining as well as fluorescence in situ hybridization with an 18S rDNA probe, are located at a terminal position on the short arms of a ST chromosome pair. C-banding marks the NORs and other weak bands distributed on telomeric regions of some chromosomes. These results give evidence that Rhamdia constitute, in terms of karyotypic macrostructure, a conserved group and support the idea that several synonymous species may be included in this genus.
first rewind previous Page / 1 next fast forward last
JavaScript is turned off in your web browser. Turn it on to take full advantage of this site, then refresh the page.