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

• Authors: A.C. Swarca , A.S. Fenocchio , M.M. Cestari , A.L. Dias
• Languages of publication: EN

Abstracts

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.

Keywords

EN

NEOTROPICAL FISHES; NOR POLYMORPHISM; STEINDACHNERIDION.

Discipline

• EXPERIMENTAL_BIOLOGY_&_MEDICINE: EXPERIMENTAL BIOLOGY & MEDICINE

• Journal: Folia Biologica
• Year: 2008
• Volume: 56
• Issue: 1-2
• Pages: 31-35

Contributors

author

A.C. Swarca

author

A.S. Fenocchio

author

M.M. Cestari

author

A.L. Dias

• Document Type: ARTICLE
• Publication order reference: Ana Claudia Swarca, Universidade Estadual de Londrina, Centro de Ciencias Biologicas, Caixa Postal 6001, 86051-970 Londrina, Parana, Brasil