Genomic Organization of Repetitive DNA Elements and Extensive Karyotype Diversity of Silurid Catfishes (Teleostei: Siluriformes): A Comparative Cytogenetic Approach

• Published in: International journal of molecular sciences 2019-07, Vol.20 (14), p.3545
• Main Authors: Ditcharoen, Sukhonthip, Antonio Carlos Bertollo, Luiz, Ráb, Petr, Hnátková, Eva, Franco Molina, Wagner, Liehr, Thomas, Tanomtong, Alongklod, Triantaphyllidis, Costas, Ozouf-Costaz, Catherine, Tongnunui, Sampan, Pengseng, Puan, Supiwong, Weerayuth, Aroutiounian, Rouben, de Bello Cioffi, Marcelo
• Format: Article
• Language: English
• Subjects: Animals; Biochemistry, Molecular Biology; Biological evolution; Catfishes - classification; Catfishes - genetics; Chromosome Banding; Chromosome number; Chromosomes; Comparative Genomic Hybridization; Cytogenetic Analysis; Cytogenetics; Deoxyribonucleic acid; DNA; Experiments; Fish; Genetic Variation; Genome; Genomes; Genomics; Genomics - methods; Hybridization; Hypotheses; In Situ Hybridization, Fluorescence; Inversions; Karyotype; Karyotypes; Life Sciences; Nucleotide sequence; Repetitive Sequences, Nucleic Acid
• ISSN: 1422-0067; 1661-6596; 1422-0067
• DOI: 10.3390/ijms20143545

The catfish family Siluridae contains 107 described species distributed in Asia, but with some distributed in Europe. In this study, karyotypes and other chromosomal characteristics of 15 species from eight genera were examined using conventional and molecular cytogenetic protocols. Our results showed the diploid number (2 ) to be highly divergent among species, ranging from 2 = 40 to 92, with the modal frequency comprising 56 to 64 chromosomes. Accordingly, the ratio of uni- and bi-armed chromosomes is also highly variable, thus suggesting extensive chromosomal rearrangements. Only one chromosome pair bearing major rDNA sites occurs in most species, except for , , and with two; and with five such pairs. In contrast, chromosomes bearing 5S rDNA sites range from one to as high as nine pairs among the species. Comparative genomic hybridization (CGH) experiments evidenced large genomic divergence, even between congeneric species. As a whole, we conclude that karyotype features and chromosomal diversity of the silurid catfishes are unusually extensive, but parallel some other catfish lineages and primary freshwater fish groups, thus making silurids an important model for investigating the evolutionary dynamics of fish chromosomes.