De novo genome assembly of the cichlid fish Astatotilapia latifasciata reveals a higher level of genomic polymorphism and genes related to B chromosomes

• Autor(a) principal: Jehangir, Maryam [UNESP]
• Data de Publicação: 2019
• Outros Autores: Ahmad, Syed F. [UNESP], Cardoso, Adauto L. [UNESP], Ramos, Erica [UNESP], Valente, Guilherme T. [UNESP], Martins, Cesar [UNESP]
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Institucional da UNESP
• Texto Completo: http://dx.doi.org/10.1007/s00412-019-00707-7; http://hdl.handle.net/11449/189166
• topic: Chromosome rearrangement; Cichlid fish; Extra chromosome; Genome evolution; Next-generation sequencing; Supernumerary chromosome

Supernumerary B chromosomes (Bs) are accessory elements to the regular chromosome set (As) and have been observed in a huge diversity of eukaryotic species. Although extensively investigated, the biological significance of Bs remains enigmatic. Here, we present de novo genome assemblies for the cichlid fish Astatotilapia latifasciata, a well-known model to study Bs. High coverage data with Illumina sequencing was obtained for males and females with 0B (B−), 1B, and 2B (B+) chromosomes to provide information regarding the diversity among these genomes. The draft assemblies comprised 771 Mb for the B− genome and 781 Mb for the B+ genome. Comparative analysis of the B+ and B− assemblies reveals syntenic discontinuity, duplicated blocks and several insertions, deletions, and inversions indicative of rearrangements in the B+ genome. Hundreds of transposable elements and 1546 protein coding sequences were annotated in the duplicated B+ regions. Our work contributes a list of thousands of genes harbored on the B chromosome, with functions in several biological processes, including the cell cycle.