Autor(es):
Milhomem, Susana Suely Rodrigues ; Souza, Augusto César Paes de ; Nascimento, Aline Lira do ; Carvalho, Jaime Ribeiro ; Feldberg, Eliana ; Pieczarka, Júlio César ; Nagamachi, Cleusa Yoshiko
Data: 2020
Origem: Oasisbr
Assunto(s): Brasil; Centromere; Chromosome Analysis; Chromosome Arm; Chromosome Banding Pattern; Chromosome Inversion; Chromosome Nor; Chromosome Pairing; Chromosome Structure; Constitutive Heterochromatin; Controlled Study; Cytotaxonomy; Female; Fish; Fish Genetics; Gc Rich Sequence; Hassar; Hassar Orestis; Karyotyping; Male; Evolution, Molecular; Nonhuman; Opsodoras; Opsodoras Ternetzi; Platydoras; Platydoras Costatus; River; Siluriformes; Species Comparison; Doradidae; Hassar (catfish); Hassar Orestis; Opsodoras; Opsodoras Ternetzi; Pisces; Platydoras; Platydoras Costatus; Siluriformes
Descrição
We studied the karyotypes of Hassar cf. orestis and an undescribed Hassar species from the Jarí River and Opsodoras ternetzi, H. orestis and Platydoras cf. costatus from the Xingú River, all with 2n = 58. Constitutive heterochromatin is located in the centromere in most metacentric pairs; in some chromosomes this banding is not present, or it is located on the whole chromosome arm or in the distal regions. The NOR is located on a single biarmed pair at a distal region of the short arm in H. cf. orestis, H. orestis and P. cf. costatus at a distal region of the long arm in O. ternetzi and at a proximal region of the long arm in the Hassar species. In all species (except for Hassar sp.) the CMA3 analysis revealed a rich G-C region coincident with the NOR. Probably inversions occurred in the NOR chromosome during the chromosomal differentiation of the Doradidae species here described. Copyright © 2008, Sociedade Brasileira de Genética.
