Localization of ribosomal genes in three Pimelodus species (Siluriformes, Pimelodidae) of the São Francisco River: 5S genes as species markers and conservation of the 18S rDNA sites

Genetics and Molecular Biology

Caroline Garcia²  Orlando Moreira Filho¹ 

[1],Universidade de São Paulo Departamento de Genética e Biologia Evolutiva São Paulo SP ,Brazil

关键词: Pimelodus;    paracentric inversion;    5S rDNA;    18S rDNA;    species marker;   

DOI  :  10.1590/S1415-47572008000200018

来源: SciELO

【 摘 要 】

Pimelodidae is one of the most representative of Neotropical catfish families. However, these fish are still poorly studied in terms of cytogenetics, especially regarding the application of more accurate techniques such as the chromosomal localization of ribosomal genes. In the present work, fluorescent in situ hybridization with 5S and 18S rDNA probes was employed for rDNA site mapping in Pimelodus sp., P. fur and P. maculatus from the São Francisco River in the Três Marias municipality - MG. The results from the application of the 18S probe confirmed the previous data obtained by silver nitrate staining, identifying a simple nucleolar organizing region system for these species. However, the labeling results from the 5S rDNA probe demonstrated a difference in the number and localization of these sites between the analyzed species. The obtained data allowed inferences on the possible processes involved in the karyotypic evolution of this genus.

【 授权许可】

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