| Autor: |
Ditcharoen S; Toxic Substances in Livestock and Aquatic Animals Research Group, Department of Biology, Faculty of Science, Khon Kaen University, Muang, Khon Kaen 40002, Thailand., Antonio Carlos Bertollo L; Departamento de Genética e Evolução, Universidade Federal de São Carlos (UFSCar), Rodovia Washington Luiz Km. 235, C.P. 676, São Carlos, SP 13565-905, Brazil., Ráb P; Laboratory of Fish Genetics, Institute of Animal Physiology and Genetics, Czech Academy of Sciences, Rumburská 89, Liběchov 277 21, Czech Republic., Hnátková E; Department of Zoology and Fisheries, Faculty of Agrobiology, Food and Natural Resources, Czech University of Life Sciences, Kamýcká 129, Prague 165 00, Czech Republic., Franco Molina W; Departamento de Biologia Celular e Genética, Centro de Biociências, Universidade Federal do Rio Grande do Norte (UFRN), Natal, RN 59078970, Brazil., Liehr T; Institute of Human Genetics, University Hospital Jena, Jena 07747, Germany., Tanomtong A; Toxic Substances in Livestock and Aquatic Animals Research Group, Department of Biology, Faculty of Science, Khon Kaen University, Muang, Khon Kaen 40002, Thailand., Triantaphyllidis C; Department of Genetics, Development and Molecular Biology, Faculty of Sciences, School of Biology, Aristotle University of Thessaloniki, University Campus, Thessaloniki 54124, Greece., Ozouf-Costaz C; Laboratorie Evolution Paris Seine, Institut de Biologie Paris Seine (IBPS), Sorbonne Universités, Case 5, 7 Quai St Bernard, Paris, 75952 Paris CEDEX 05, France., Tongnunui S; Department of Conservation Biology, Mahidol University, Kanchanaburi Campus, Sai Yok, Kanchanaburi Province 71150, Thailand., Pengseng P; School of Agricultural of Technology, Walailak University, Thasala, Nakhon Si Thammarat 80160, Thailand., Supiwong W; Faculty of Applied Science and Engineering, Khon Kaen University, Nong Khai Campus, Muang, Nong Khai 43000, Thailand., Aroutiounian R; Department of Genetics and Cytology, Yerevan State University, Yerevan 0025, Armenia., de Bello Cioffi M; Departamento de Genética e Evolução, Universidade Federal de São Carlos (UFSCar), Rodovia Washington Luiz Km. 235, C.P. 676, São Carlos, SP 13565-905, Brazil. mbcioffi@ufscar.br. |
| Abstrakt: |
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 n ) to be highly divergent among species, ranging from 2 n = 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 Wallago micropogon , Ompok siluroides , and Kryptoterus giminus with two; and Silurichthys phaiosoma 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. |
