Artículos de revistas
Molecular cytogenetics characterization of Rhinoclemmys punctularia (Testudines, Geoemydidae) and description of a Gypsy-H3 association in its genome
Fecha
2020-05-15Registro en:
Gene. Amsterdam: Elsevier, v. 738, 7 p., 2020.
0378-1119
10.1016/j.gene.2020.144477
WOS:000523629200013
8858800699425352
0000-0003-3534-974X
Autor
Univ Fed Para
Universidade Estadual de Ponta Grossa (UEPG)
Univ Fed Rural Amazonia
Universidade Estadual Paulista (Unesp)
Institución
Resumen
The wide variation found in the size of eukaryotic genomes is largely related to the accumulation of repetitive sequences. Studies show that these sequences can go through an evolutionary process (molecular co-optation) and acquire new genomic functions. Cytogenetic studies reveal a wide karyotypic variation between chelonians (order Testudines) (2n = 26-68), attributed mainly to the number of microchromosomes. The study of repetitive DNAs has the potential to provide data on the dynamics of these sequences, and how they influence the organization of the genome. Here, we reveal the first in situ mapping data of 45S rDNA, histone H3 genes, and telomeric sequences, for a species of the genus Rhinoclemmys, R. punctularia. The karyotype described here for R. punctularia is different from previous reports for the diploid complement of this species, with differences probably attributable to centric fissions and pericentric inversions or centromere repositioning. The 45S rDNA are on a single chromosome pair (like in other turtles), telomeric sequences are in terminal position on all the chromosomes, and histone H3 is dispersed in low copy number, with clusters in pericentromeric regions of three chromosome pairs. We report on the presence of a Gypsy retrotransposon insert located within H3 histone of R. punctularia, and the H3 region sequenced contained the open reading frame of the histone sequence. Comparative modeling revealed a functional pattern for the protein, thus suggesting that the Gypsy element might have been recruited for new functions in the genome of this species.