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

• Autorzy: A.C. Swarca , A.S. Fenocchio , M.M. Cestari , A.L. Dias
• Języki publikacji: EN

Abstrakty

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.

Słowa kluczowe

EN

NEOTROPICAL FISHES; NOR POLYMORPHISM; STEINDACHNERIDION.

• Czasopismo: Folia Biologica
• Rocznik: 2008
• Tom: 56
• Numer: 1-2
• Strony: 31-35

Twórcy

autor

A.C. Swarca

autor

A.S. Fenocchio

autor

M.M. Cestari

autor

A.L. Dias

• Typ dokumentu: ARTICLE
• Bibliografia: Ana Claudia Swarca, Universidade Estadual de Londrina, Centro de Ciencias Biologicas, Caixa Postal 6001, 86051-970 Londrina, Parana, Brasil