S.M.H.K. Mizoguchi, A.L.B. Portela-Castro, I.C. Martins-Santos
Published September 30, 2007
Genet. Mol. Res. 6 (3): 650-656 (2007)

About the authors
S.M.H.K. Mizoguchi, A.L.B. Portela-Castro, I.C. Martins-Santos

Corresponding author
I.C. Martins-Santos
E-mail: icmdsantos@uem.br

ABSTRACT
 Three populations of the genus Crenicichla, namely Crenicichla iguassuensis, Crenicichla sp 1 and Crenicichla sp 2, from the Iguaçu River, were analyzed cytogenetically, and their nucleolus or- ganizer regions, constitutive heterochromatin distribution and chro- momycin A, markings were studied. Karyotype analyses showed a diploid number of 48 chromosomes, made up of 2 metacentric pairs, 2 submetacentric pairs, 7 subtelocentric pairs, and 13 acrocentric pairs for the three Crenicichla species and no sexual chromosome differen- tiation. Nucleolus organizer regions showed strong interstitial mark- ing on the first chromosome pair, coincident with a constriction pre- sented by Giemsa and positive marking by chromomycin. Althoughconstitutive heterochromatin patterns were also similar, with peri- centromeric markings, small differences in the three species could be observed. Crenicichla sp 2 presented some chromosomes with bitelomeric markings absent in Crenicichla iguassuensis and Creni- cichla sp 1.

Key words: Karyotype, Nucleolus organizer region banding, C banding, Cichlidae, Crenicichla iguassuensis, Perciformes