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Analyses of the structure of NORs in two species of South American Sorubiminae fishes (Siluriformes) by means of several cytogenetic techniques
- Source :
- Folia biologica. 56(1-2)
- Publication Year :
- 2008
-
Abstract
- 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.
- Subjects :
- Genetics
Silver Staining
Indoles
biology
Secondary constriction
Heterochromatin
EcoRI
General Medicine
biology.organism_classification
General Biochemistry, Genetics and Molecular Biology
Chromosomes
chemistry.chemical_compound
Restriction enzyme
chemistry
Evolutionary biology
Neotropical fish
Steindachneridion
biology.protein
Nucleolus Organizer Region
Animals
DAPI
BamHI
Catfishes
In Situ Hybridization, Fluorescence
Subjects
Details
- ISSN :
- 00155497
- Volume :
- 56
- Issue :
- 1-2
- Database :
- OpenAIRE
- Journal :
- Folia biologica
- Accession number :
- edsair.doi.dedup.....f38700cb776020b9cc630783e88f69eb