2025-06-052025-06-052023-12-14BARROS, Nayza Silva. Mapeamento de sequências repetitivas no cariótipo de Gymnotus carapo (Gymnotiformes, Teleostei) da Área de Proteção Ambiental (APA) da Ilha do Combú, Belém, Pará. Orientadora: Cleusa Yoshiko Nagamachi. 2023. 36 f. Trabalho de Curso (Licenciatura em Ciências Biológicas) – Faculdade de Ciências Biológicas, Universidade Federal do Pará, Belém, 2025. Disponível em: https://bdm.ufpa.br/handle/prefix/8286. Acesso em:.https://bdm.ufpa.br/handle/prefix/8286Gymnotus (Gymnotiformes) is a genus of electric fish that use low-intensity discharges for communication and predation. This group has a great karyotypic diversity with a diploid number (2n) ranging from 34 to 54 chromosomes. Repetitive sequences are important markers that can help in understanding the karyotypic evolution of species, especially cryptic ones, such as Gymnotus carapo. Aiming to understand the karyotypic structure and evolution of the group, cytogenetic studies were carried out using FISH with U2 snRNA probes, telomeric sequences, 5S rDNA and 18S rDNA on Gymnotus samples collected in the APA of Ilha do Combú, Belém, Pará, Brazil. The results show that Gymnotus carapo “Combú” has 2n = 42 and a karyotypic formula of 32 m/sm and 10 st/a. Constitutive heterochromatin occurs in the centromeric region of chromosomes, with small interstitial bands on some chromosomes. The 18S rDNA is found in a single metacentric pair in the proximal region of the long arm. The 5S rDNA is also found in a single metacentric pair in the proximal region of the long arm. The U2 snRNA was evidenced in the centromeric region of a metacentric pair. Telomeric sequences occur in the distal region of all chromosomes, with interstitial sequences being found in a metacentric pair and an acrocentric pair. These results show that the species is in a process of diversification, evidenced by the various rearrangements that have occurred, the diversity in 2n and the marking of signals that occurs in the group.Acesso AbertoGymnotusPeixe elétricoCariótipoCitogenéticaEnguia elétricaAnálise citogenéticaDNA ribossomicoDNA repetitivoEspécie crípticaElectric eelCNPQ::CIENCIAS BIOLOGICAS::GENETICA::GENETICA ANIMALTrabalho de Curso - Graduação - MonografiaAttribution-NonCommercial-NoDerivs 3.0 Brazil