Structural and Numerical Chromosome Diversification in Marine Perciformes (Priacanthidae and Gerreidae)
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The Perciformes are characterized by a remarkable chromosomal homogeneity, with a small percentage of its representatives bearing diploid numbers higher or lower than their putative basal number (2<i>n</i>=48). Due to the wide diversity of this group, several families from this order lack cytogenetic reports, such as Gerreidae and Priacanthidae. Chromosomal analyses were carried out in the species <i>Diapterus olithostomus</i> (Gerreidae) and <i>Priacanthus arenatus</i> (Priacanthidae), from Brazilian coast. The karyotype of <i>D. olithostomus</i> is composed by 2<i>n</i>=48 (NF=48), while <i>P. arenatus</i> presented 2<i>n</i>=52 (4st+48a; FN=56). C-banding analysis revealed heterochromatic blocks on centromeric and/or interstitial regions in the 2 species. In <i>D. olithostomus</i>, GC-rich blocks were identified at interstitial position and on ribosomal sites. This species shows the typical karyotype pattern of Perciformes, but the presence of GC-rich interstitial heterochromatin, as well as the presence of 2<i>n</i>>48 in <i>P. arenatus</i>, represents possible autopomorphies. The results report both structural and numerical rearrangements within this order.
CYTOLOGIA 71(3), 237-242, 2006-09-25
Japan Mendel Society, International Society of Cytology