Cytogenetic studies in Hasemania crenuchoides (Characiformes: Characidae) and molecular investigations into kinship relationships of the genus

ABSTRACT

The genus Hasemania is considered incertae sedis from the family Characidae which possesses nine fish species. Hasemania crenuchoides is endemic to the Federal District of Brazil and is under threat of extinction. The objective of this work was to characterize the Hasemania crenuchoides karyotype and investigate phylogenetic relationships using the 5ʹ region of the COI gene. Our results showed a chromosome number of 2n = 50, with a fundamental number equal to 82 and a karyotype formula of 32m/sm+ 18st/a. C banding evidenced that constitutive heterochromatin is not only present in pericentromeric regions, but also in telomeric and interstitial regions. Ag-NOR marking occurred in the short arm of pair 6. DAPI staining revealed that few bands were rich in A/T. The diploid number observed is in accordance with previous findings in Characidae, including the presence of a long metacentric pair, and is considered a plesiomorphic character. Based on the literature, together with cytogenetic and molecular data, it is suggested that Hasemania is possibly not monophyletic, composed of two groups: (1) a basal group with H. hanseni and H. nana; and (2) a derived group with H. crenuchoides, H. kalunga, and H. uberaba. Therefore, the molecular and cytogenetic data presented may contribute to understanding phylogenetic relationships within the family.

KEYWORDS:

• Cytogenetics
• cytochrome oxidase
• C-banding
• DAPI
• Ag-NOR

Acknowledgments

The authors thank Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) from the Pro-Amazonia Project number 3284/2013 for financial support. We thank Edgar Guimarães Bione, a teacher from the University of Brasília-Ceilândia, for help in collection of Hasemania. We thank the Instituto Chico Mendes de Conservação da Biodiversidade (ICMBio) for the collection permits n° 42573-1 and 36170-1/2014.

Disclosure statement

No potential conflict of interest was reported by the authors.

Supplementary material

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Additional information

Funding

This work was supported by the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior [3284/2013].