Sember Alexandr, Bertollo Luiz A C, Ráb Petr, Yano Cassia F, Hatanaka Terumi, de Oliveira Ezequiel A, Cioffi Marcelo de Bello
Laboratory of Fish Genetics, Institute of Animal Physiology and Genetics, Czech Academy of Sciences, Liběchov, Czechia.
Departamento de Genética e Evolução, Universidade Federal de São Carlos, São Carlos, Brazil.
Front Genet. 2018 Mar 5;9:71. doi: 10.3389/fgene.2018.00071. eCollection 2018.
The Erythrinidae family (Teleostei: Characiformes) is a small Neotropical fish group with a wide distribution throughout South America, where corresponds to the most widespread and cytogenetically studied taxon. This species possesses significant genetic variation, as well as huge karyotype diversity among populations, as reflected by its seven major karyotype forms (i.e., karyomorphs A-G) identified up to now. Although morphological differences in their bodies are not outstanding, . karyomorphs are easily identified by differences in 2, morphology and size of chromosomes, as well as by distinct evolutionary steps of sex chromosomes development. Here, we performed comparative genomic hybridization (CGH) to analyse both the intra- and inter-genomic status in terms of repetitive DNA divergence among all but one (E) karyomorphs. Our results indicated that they have close relationships, but with evolutionary divergences among their genomes, yielding a range of non-overlapping karyomorph-specific signals. Besides, male-specific regions were uncovered on the sex chromosomes, confirming their differential evolutionary trajectories. In conclusion, the hypothesis that . karyomorphs are result of speciation events was strengthened.
锯脂鲤科（硬骨鱼纲：脂鲤目）是新热带区一个小型鱼类群体，广泛分布于南美洲，是该地区分布最广且细胞遗传学研究最多的分类单元。该物种具有显著的遗传变异，种群间核型多样性也极为丰富，目前已识别出七种主要核型形式（即核型A - G）。尽管它们身体形态差异并不显著，但这些核型可通过染色体形态和大小的差异以及性染色体发育的不同进化阶段轻易识别。在此，我们进行了比较基因组杂交（CGH），以分析除一种（E）核型外的所有核型在重复DNA差异方面的基因组内和基因组间状态。我们的结果表明，它们关系密切，但基因组间存在进化差异，产生了一系列不重叠的核型特异性信号。此外，在性染色体上发现了雄性特异性区域，证实了它们不同的进化轨迹。总之，核型是物种形成事件结果的假设得到了加强。
