Landscape of Transposable Elements Focusing on the B Chromosome of the Cichlid Fish Astatotilapia latifasciata

Autor(es)

Coan, Rafael L. B. ^[1] ; Martins, Cesar ^[1]

Afiliação do(s) autor(es)

^[1] Sao Paulo State Univ, UNESP, Dept Morphol, Inst Biosci, BR-18618689 Botucatu, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: GENES; v. 9, n. 6 JUN 2018.
• Citações Web of Science: 8

Resumo

B chromosomes (Bs) are supernumerary elements found in many taxonomic groups. Most B chromosomes are rich in heterochromatin and composed of abundant repetitive sequences, especially transposable elements (TEs). B origin is generally linked to the A-chromosome complement (A). The first report of a B chromosome in African cichlids was in Astatotilapia latifasciata, which can harbor 0, 1, or 2 Bs Classical cytogenetic studies found high a TE content on this B chromosome. In this study, we aimed to understand TE composition and expression in the A. latifasciata genome and its relation to the B chromosome. We used bioinformatics analysis to explore the genomic organization of TEs and their composition on the B chromosome. The bioinformatics findings were validated by fluorescent in situ hybridization (FISH) and real-time PCR (qPCR). A. latifasciata has a TE content similar to that of other cichlid fishes and several expanded elements on its B chromosome. With RNA sequencing data (RNA-seq), we showed that all major TE classes are transcribed in the brain, muscle, and male and female gonads. An evaluation of TE transcription levels between B- and B+ individuals showed that few elements are differentially expressed between these groups and that the expanded B elements are not highly transcribed. Putative silencing mechanisms may act on the B chromosome of A. latifasciata to prevent the adverse consequences of repeat transcription and mobilization in the genome. (AU)

• Processo FAPESP: 14/16763-6 - Análise genômica em larga escala de elementos repetitivos com foco em cromossomos B do ciclídeo Astatotilapia latifasciata
• Beneficiário: Rafael Luiz Buogo Coan
• Linha de fomento: Bolsas no Brasil - Mestrado
• Processo FAPESP: 15/16661-1 - Cromossomos sexuais, cromossomos B e seus enigmas: sistemas modelo para estudos de evolução cromossômica e genômica
• Beneficiário: César Martins
• Linha de fomento: Auxílio à Pesquisa - Temático
• Processo FAPESP: 13/04533-3 - Análise funcional de cromossomos B, utilizando o peixe ciclídeo Astatotilapia latifasciata como modelo
• Beneficiário: César Martins
• Linha de fomento: Auxílio à Pesquisa - Regular