Open AccessKaryotype Evolution of Talking Thorny Catfishes Anadoras (Doradidae, Astrodoradinae): A Process Mediated by Structural Rearrangements and Intense Reorganization of Repetitive DNAs
Author(s) -
Fábio Hiroshi Takagui,
Lucas Baumgärtner,
Patrik Ferreira Viana,
Moema Cristina Costa de Lima,
Jamille de Araújo Bitencourt,
Paulo César Vênere,
Roberto Laridondo Lui,
Orlando MoreiraFilho,
Eliana Feldberg,
Fernanda Simões de Almeida,
José Luís Olivan Birindelli,
Lúcia Giuliano-Caetano
Publication year - 2022
Publication title -
cytogenetic and genome research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.571
H-Index - 88
ISSN - 1424-8581
DOI - 10.1159/000523747
Subject(s) - biology , karyotype , subfamily , evolutionary biology , phylogenetic tree , phylogenetics , heterochromatin , zoology , genetics , chromosome , gene
Anadoras is a thorny catfish genus widespread through the Amazon and Paraguay river basins. It includes 2 nominal species, A. grypus and A. weddellii, plus Anadoras sp. "araguaia," an undescribed species only recognized morphologically. Since Anadoras occupies a basal position within the Astrodoradinae phylogeny, it is crucial to identify its cytogenetic features to comprehend the mechanisms involved in the chromosomal diversification of this subfamily. Therefore, we performed a comparative cytogenetic analysis including all species of Anadoras. Furthermore, we applied a species delimitation analysis based on 600 bp of the mitochondrial cytochrome oxidase subunit 1 (CO1) gene to investigate the taxonomic status of the species. Cytogenetic markers revealed a high degree of similarity among Anadoras weddellii and Anadoras sp. "araguaia," both have 2n = 56 chromosomes (24m + 10sm + 22st/a), single NOR sites on acrocentric pair 28, and 5S rDNA sites on submetacentric pair 15. A. grypus has the most divergent chromosomal characteristics because, even though it also has 2n = 56 chromosomes, it exhibits several differences in the chromosome formula, heterochromatin distribution, and number/position of the rDNA sites. In sum, we believe that the chromosome diversification of Anadoras is due to 4 mechanisms: centric fusion, pericentric/paracentric inversions, nonreciprocal translocations, and activity of transposable elements. Additionally, our phylogenetic tree revealed well-supported clades and, by barcode species delimitation analysis, confirmed the existence of 3 molecular operational taxonomic units, including the putative new species Anadoras sp. "araguaia."