Moraes Juliana Nascimento, Viana Patrik Ferreira, Favarato Ramon Marin, Pinheiro-Figliuolo Vanessa Susan, Feldberg Eliana
Instituto Nacional de Pesquisas da Amazônia (INPA), Coordenação de Biodiversidade, Laboratório de Genética Animal, Manaus, AM, Brazil.
Genet Mol Biol. 2022 Jun 27;45(2):e20210125. doi: 10.1590/1678-4685-GMB-2021-0125. eCollection 2022.
Fishes of the Curimatidae family represent one of the most important freshwater ichthyofauna groups of Central and South America, with 117 recognized species distributed in eight genera. In this study, six species - Curimata inornata, Curimatella dorsalis, and Psectrogaster falcata collected from the Lower Araguaia River, Pará, Brazil; Curimata vittata, Curimatella meyeri, and Psectrogaster rutiloides collected from the Catalão Lake, Amazonas, Brazil - were cytogenetically analyzed, investigate the occurrence and distribution of repetitive DNA classes in the karyotypes. All species had 2n=54 metacentric/submetacentric chromosomes. Despite the conservative diploid number, we observed variations in the karyotypic structure among species. Ribosomal DNA (rDNA) 18S and 5S were found in single or multiple sites, with the first report of synteny in Curimatella dorsalis, and the occurrence of several interstitial telomeric sequences (ITSs) in species of the genera Curimatella and Psectrogaster. Interspecific karyotypic diversity both concerning structure and location/position of the nucleolar organizer regions (NOR) and ribosomal DNA, suggesting the occurrence of several non-Robertsonian rearrangements driving the evolution of this family.
曲口鱼科鱼类是中美洲和南美洲最重要的淡水鱼类群之一，有117个已确认物种，分布在8个属中。在本研究中，对6个物种进行了细胞遗传学分析，以研究核型中重复DNA类别的出现和分布情况，这6个物种分别是：从巴西帕拉州下阿拉瓜亚河采集的无饰曲口鱼、背点小曲口鱼和镰状翼口鱼；从巴西亚马孙州卡塔朗湖采集的带纹曲口鱼、迈氏小曲口鱼和红腹翼口鱼。所有物种都有2n = 54条中着丝粒/亚中着丝粒染色体。尽管二倍体数目保守，但我们观察到物种间核型结构存在差异。核糖体DNA（rDNA）的18S和5S位于单个或多个位点，首次报道了背点小曲口鱼的同线性，并且在小曲口鱼属和翼口鱼属的物种中发现了几个间插端粒序列（ITS）。核仁组织区（NOR）和核糖体DNA在结构以及位置/定位方面的种间核型多样性，表明发生了几种非罗伯逊重排推动了该科的进化。
