Chromosome analysis in Saccodon wagneri (Characiformes) and insights into the karyotype evolution of Parodontidae

Autor(es)

Mauro Nirchio ; Maria Cecilia Masache ^[2] ; Fabilene Gomes Paim ^[3] ; Marcelo de Bello Cioffi ^[4] ; Orlando Moreira Filho ^[5] ; Ramiro Barriga ^[6] ; Claudio Oliveira ^[7] ; Anna Rita Rossi ^[8]

• Tipo de documento: Artigo Científico
• Fonte: Neotropical Ichthyology; v. 19, n. 1 2021-02-22.

Resumo

ABSTRACT Parodontidae is a relatively small group of Neotropical characiform fishes consisting of three genera (Apareiodon, Parodon, and Saccodon) with 32 valid species. A vast cytogenetic literature is available on Apareiodon and Parodon, but to date, there is no cytogenetic data about Saccodon, a genus that contains only three species with a trans-Andean distribution. In the present study the karyotype of S. wagneri was described, based on both conventional (Giemsa staining, Ag-NOR, C-bands) and molecular (repetitive DNA mapping by fluorescent in situ hybridization) methods. A diploid chromosome number of 2n = 54 was observed in both sexes, and the presence of heteromorphic sex chromosomes of the ZZ/ZW type was detected. The W chromosome has a terminal heterochromatin band that occupies approximately half of the long arm, being this band approximately half the size of the Z chromosome. The FISH assay showed a synteny of the 18S-rDNA and 5S-rDNA genes in the chromosome pair 14, and the absence of interstitial telomeric sites. Our data reinforce the hypothesis of a conservative karyotype structure in Parodontidae and suggest an ancient origin of the sex chromosomes in the fishes of this family. (AU)

• Processo FAPESP: 14/26508-3 - Filogenia da hiperdiversa ordem Characiformes (Teleostei: Ostariophysi) utilizando elementos ultraconservados
• Beneficiário: Claudio de Oliveira
• Modalidade de apoio: Auxílio à Pesquisa - Temático
• Processo FAPESP: 18/20610-1 - Estudo da biogeografia da costa do Brasil utilizando dados da genética de populações de bagres marinhos dos gêneros Cathorops e Genidens
• Beneficiário: Claudio de Oliveira
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 16/09204-6 - Biodiversidade e Biogeografia em peixes marinho-estuarinos (Teleostei) do Brasil
• Beneficiário: Claudio de Oliveira
• Modalidade de apoio: Auxílio à Pesquisa - Regular