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Intrapopulational polymorphism of nucleolus organizer regions in Serrapinnus notomelas (Characidae, Cheirodontinae) from the Paraná River
Author(s) -
SantiRampazzo A. P.,
Nishiyama P. B.,
Ferreira P. E. B.,
MartinsSantos I. C.
Publication year - 2008
Publication title -
journal of fish biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.672
H-Index - 115
eISSN - 1095-8649
pISSN - 0022-1112
DOI - 10.1111/j.1095-8649.2007.01784.x
Subject(s) - biology , characidae , nucleolus organizer region , genetics , nucleolus , fluorescence in situ hybridization , characiformes , cytogenetics , karyotype , homologous chromosome , chromosome , evolutionary biology , gene , fish <actinopterygii> , fishery , cytoplasm
Analysis of the nucleolus organizer regions by silver nitrate (AgNOR), fluorescent in situ hybridization (FISH) and C‐banding of Serrapinnus notomelas from the Paraná River, PR, Brazil revealed intrapopulational polymorphisms that could be classified into six patterns (I–VI). Pattern I consisted of a single nucleolus organizer region (NOR) on chromosome pair 26 with at least one active homologue, indicating that it was a preferential NO. This NOR was also present in all the other patterns. In addition, seven other variable pairs appeared in patterns II–VI. These polymorphisms may indicate transpositions of rDNA genes, located on pair 26, to various sites in the genome. These transpositions may be due to transpose mechanisms or reinsertion into sites that have sequences homologous with the inserts. C‐band analysis also reflected this variability and confirmed the various patterns described here.