Chromosomal mapping of 18S-28S and 5S rRNA genes by two-colour fluorescent in situ hybridization in six sturgeon species

The number and distribution of the 18S-28S and 5S rRNA (rDNA) gene sequences were examined on mitotic chromosomes of six sturgeon species by two-colour in situ hybridization. Four of the six species, Huso huso, Acipenser stellatus, Acipenser sturio, and Acipenser ruthenus, with about 120 chromosomes...

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Bibliographic Details
Published in:Genome
Main Authors: FONTANA, Francesco, CHICCA, Milvia, ROSSI, Remigio, LANFREDI M., CONGIU L., LEIS, Marilena
Other Authors: Fontana, Francesco, Lanfredi, M., Congiu, L., Leis, Marilena, Chicca, Milvia, Rossi, Remigio
Format: Article in Journal/Newspaper
Language:English
Published: 2003
Subjects:
Acipenseriforme
FISH
Fish cytogenetic
Ribosomal gene
Acipenser baerii
Online Access:http://hdl.handle.net/11392/516737
https://doi.org/10.1139/g03-007
Description
Summary:The number and distribution of the 18S-28S and 5S rRNA (rDNA) gene sequences were examined on mitotic chromosomes of six sturgeon species by two-colour in situ hybridization. Four of the six species, Huso huso, Acipenser stellatus, Acipenser sturio, and Acipenser ruthenus, with about 120 chromosomes, showed from six to eight 18S-28S rDNA signals, while 5S rDNA signals were on only one chromosome pair. The two species with 250-270 chromosomes, Acipenser baerii and Acipenser transmontanus, showed from 10 to 12 18S-28S sites and two chromosome pairs bearing 5S rDNA signals. In all examined species, the rather intense 5S rDNA signals apparently overlapped those of 18S-28S rDNA. These data support the diploid-tetraploid relationships between the two chromosome groups of sturgeons. The close association between the two rDNA families in species belonging to an ancestral fish order, such as Acipenseriformes, supports the hypothesis that the association represents a primitive condition.

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