Coan, Rafael L. B. [UNESP]Martins, Cesar [UNESP]2018-12-112018-12-112018-06-01Genes, v. 9, n. 6, 2018.2073-4425http://hdl.handle.net/11449/179914B 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.engCytogeneticsEvolutionExtra chromosomesGenomicsRepetitive elementsRNA-SeqSupernumerary elementsArtigo10.3390/genes9060269Acesso aberto2-s2.0-850479216842-s2.0-85047921684.pdf88588006994253520000-0003-3534-974X