Document Detail

Post-zygotic modifications and intra- and inter-individual nucleolar organizing region variations in fish: report of a case involving Leporinus friderici.
MedLine Citation:
PMID:  7551542     Owner:  NLM     Status:  MEDLINE    
Silver nitrate staining, a rapid and efficient method, has proven to be excellent for nucleolar organizing region (NOR) studies in fish. Some fish appear to have only two NOR-bearing chromosomes in their karyotype, whereas others probably have several. In the present study we analyzed the NORs of Leporinus friderici, a species that, on the basis of previous studies, has been considered as representative of species with NORs carried by a single chromosome pair. The analyses were performed by a combination of three methods, i.e. silver nitrate staining, staining with the GC-specific fluorochrome chromomycin A3, and in situ hybridization with digoxigenin-labeled probes. The results showed that, although more frequent and conspicuous in a single chromosome pair, the NORs of this species are present in multiple chromosomes. Intra- and inter-individual variations observed by the three methods strongly suggest the occurrence of post-zygotic modifications involving NORs. NOR identification in fish, almost exclusively performed by the silver nitrate method, is currently being re-evaluated by methods such as chromomycin A3 staining and in situ hybridization, which may provide important information leading to a better understanding of chromosome evolution in these animals.
P M Galetti; C A Mestriner; P J Monaco; E M Rasch
Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  Chromosome research : an international journal on the molecular, supramolecular and evolutionary aspects of chromosome biology     Volume:  3     ISSN:  0967-3849     ISO Abbreviation:  Chromosome Res.     Publication Date:  1995 Aug 
Date Detail:
Created Date:  1995-11-03     Completed Date:  1995-11-03     Revised Date:  2006-11-15    
Medline Journal Info:
Nlm Unique ID:  9313452     Medline TA:  Chromosome Res     Country:  ENGLAND    
Other Details:
Languages:  eng     Pagination:  285-90     Citation Subset:  IM    
Department of Genetics and Evolution, Federal University of São Carlos, Brazil.
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MeSH Terms
Chromosome Banding
Fishes / genetics*
In Situ Hybridization, Fluorescence
Nucleolus Organizer Region / ultrastructure*
Silver Nitrate
Silver Staining
Reg. No./Substance:
7761-88-8/Silver Nitrate

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