Open AccessMultiple NORs in Bryconamericus aff. exodon (Osteichthyes, Characidae, Tetragonopterinae)
Author(s) -
PAINTNERMARQUES TÂNIA REGINA,
GIULIANOCAETANO LUCIA,
DIAS ANA LÚCIA
Publication year - 2002
Publication title -
hereditas
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.819
H-Index - 50
eISSN - 1601-5223
pISSN - 0018-0661
DOI - 10.1034/j.1601-5223.2002.01651.x
Subject(s) - characidae , biology , chromomycin a3 , fish <actinopterygii> , ploidy , fluorescence in situ hybridization , population , ribosomal rna , zoology , genetics , nucleolus organizer region , in situ hybridization , karyotype , chromosome , microbiology and biotechnology , fishery , gene , gene expression , demography , sociology
Fifteen examples of Bryconamericus aff . exodon from the Três Bocas stream in the basin of the Tibagi river (Paraná, Brazil) were analyzed. They presented a diploid number of 52 chromosomes. Multiple NORS were detected by silver nitrate impregnation in the telomeric region on the short or long arm of different chromosomes, showing a variation from 2 to 5 NOR‐bearing chromosomes. Treatment with chromomycin A 3 (CMA 3 ) showed regions rich in GC in different chromosomes, probably coincident with the AgNORS. In situ hybridization by fluorescence (FISH) with 18S rDNA probe showed 8 hybridization signs in the telomeric regions of the chromosomes, proving that this B. aff . exodon population has a greater number of ribosomal cistrons than were detected by Ag‐banding.