Karyotypic diversification of the Doradinae
Posted: 30 Nov 2021, 18:07
Takagui, F.H., Viana, P., Baumgärtner, L., Bitencourt, J.A., Margarido, V.P., Lui, R.L., Feldberg, E., Birindelli, J.L.O., Almeida, F.S. & Giuliano-Caetano, L. (2021). Reconstruction of the Doradinae (Siluriformes-Doradidae) ancestral diploid number and NOR pattern reveals new insights about the karyotypic diversification of the Neotropical thorny catfishes. Genetics and Molecular Biology, 44. e20200068
https://doi.org/10.1590/1678-4685-GMB-2020-0068
https://www.scielo.br/j/gmb/a/QdcLGvd9tFd6TBPFxfwt6qJ/
https://doi.org/10.1590/1678-4685-GMB-2020-0068
https://www.scielo.br/j/gmb/a/QdcLGvd9tFd6TBPFxfwt6qJ/
Abstract
Doradinae (Siluriformes: Doradidae) is the most species-rich subfamily among thorny catfishes, encompassing over 77 valid species, found mainly in Amazon and Platina hydrographic basins. Here, we analyzed seven Doradinae species using combined methods (e.g., cytogenetic tools and Mesquite ancestral reconstruction software) in order to scrutinize the processes that mediated the karyotype diversification in this subfamily. Our ancestral reconstruction recovered that 2n=58 chromosomes and simple nucleolar organizer regions (NOR) are ancestral features only for Wertheimerinae and the most clades of Doradinae. Some exceptions were found in (2n=56), (2n=60), (2n=66) and whose karyotypes showed a multiple NOR system. The large thorny catfishes, such as , and share several karyotype features, with subtle variations only regarding their heterochromatin distribution. On the other hand, a remarkable karyotypic variability has been reported in the fimbriate barbells thorny catfishes. These two contrasting karyoevolution trajectories emerged from a complex interaction between chromosome rearrangements (e.g., inversions and Robertsonian translocations) and mechanisms of heterochromatin dispersion. Moreover, we believe that biological features, such as microhabitats preferences, populational size, low vagility and migratory behavior played a key role during the origin and maintenance of chromosome diversity in Doradinae subfamily.
- Keywords: Karyotypic diversification; Cytotaxonomy; 5S rDNA; 18S rDNA; Heterochromatin