Data from: The evolutionary dynamics of ribosomal genes, histone H3 and transposable Rex elements in the genome of Atlantic snappers

Lutjanidae is a family of primarily marine and carnivorous fishes distributed in the Atlantic, Indian and Pacific oceans, with enormous economic and ecological importance. In order to better clarify the conservative chromosomal evolution of Lutjanidae, we analyzed the evolutionary dynamics of five repetitive DNA classes in five Lutjanus and in one Ocyurus species from Western Atlantic. The ribosomal 18S sites were generally located in a single chromosome pair, except for L. jocu and L. alexandrei where they are found in two pairs. In turn, the 5S rDNA sites are unique, terminal and non-syntenic with the 18S rDNA sites. In three species analyzed, H3 hisDNA genes were found in one chromosomal pair. However, while L. jocu presented two H3 sites, O. chrysurus showed a noteworthy dispersion of this gene in almost all chromosomes of the karyotype. Retrotransposons Rex1 and Rex3, do not exhibit any association with the explosive distribution of H3 sequences in O. chrysurus. The low compartmentalization of Rex elements, in addition to the general non-dynamic distribution of ribosomal and H3 genes, corroborate the karyotype conservatism in Lutjanidae species, also at the microstructural level. However, some “disturbing evolutionary waves” can break down this conservative scenario, as evidenced by the massive random dispersion of H3 hisDNA in the genome of O. chrysurus. The implication of the genomic expansion of H3 histone genes and their functionality remain unknown, although suggesting that they have higher evolutionary dynamics than previously thought.