Sex Chromosome Evolution and Genomic Divergence in the Fish Hoplias malabaricus (Characiformes, Erythrinidae)

Frontiers in Genetics

Marcelo de Bello Cioffi¹  Luiz A. C. Bertollo¹  Cassia F. Yano¹  Terumi Hatanaka¹  Alexandr Sember²  Petr Ráb²  Ezequiel A. de Oliveira³ 

[1] Departamento de Genética e Evolução, Universidade Federal de São Carlos, São Carlos, Brazil;Laboratory of Fish Genetics, Institute of Animal Physiology and Genetics, Czech Academy of Sciences, Liběchov, Czechia;Secretaria de Estado de Educação de Mato Grosso (SEDUC-MT), Cuiabá, Brazil;

关键词: fish cytogenetics;    multiple sex chromosomes;    sex-determining region;    sex chromosome turnover;    CGH;    intraspecific variability;   

DOI  :  10.3389/fgene.2018.00071

来源: DOAJ

【 摘 要 】

The Erythrinidae family (Teleostei: Characiformes) is a small Neotropical fish group with a wide distribution throughout South America, where Hoplias malabaricus 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, H. malabaricus karyomorphs are easily identified by differences in 2n, 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) H. malabaricus 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 H. malabaricus karyomorphs are result of speciation events was strengthened.

【 授权许可】

Unknown