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Molecular Cytogenetic Analysis of the European Hake Merluccius merluccius (Merlucciidae, Gadiformes): U1 and U2 snRNA Gene Clusters Map to the Same Location.

García-Souto D, Troncoso T, Pérez M, Pasantes JJ - PLoS ONE (2015)

Bottom Line: Concerning rRNA genes, this species show a single 45S rDNA cluster at an intercalary location on the long arm of subtelocentric chromosome pair 12; the single 5S rDNA cluster is also intercalary to the long arm of chromosome pair 4.While U2 snRNA gene clusters map to a single subcentromeric position on chromosome pair 13, U1 snRNA gene clusters seem to appear on almost all chromosome pairs, but showing bigger clusters on pairs 5, 13, 16, 17 and 19.The brightest signals on pair 13 are coincident with the single U2 snRNA gene cluster signals.

View Article: PubMed Central - PubMed

Affiliation: Departamento de Bioquímica, Xenética e Inmunoloxía, Universidade de Vigo, Vigo, Spain.

ABSTRACT
The European hake (Merluccius merluccius) is a highly valuable and intensely fished species in which a long-term alive stock has been established in captivity for aquaculture purposes. Due to their huge economic importance, genetic studies on hakes were mostly focused on phylogenetic and phylogeographic aspects; however chromosome numbers are still not described for any of the fifteen species in the genus Merluccius. In this work we report a chromosome number of 2n = 42 and a karyotype composed of three meta/submetacentric and 18 subtelo/telocentric chromosome pairs. Telomeric sequences appear exclusively at both ends of every single chromosome. Concerning rRNA genes, this species show a single 45S rDNA cluster at an intercalary location on the long arm of subtelocentric chromosome pair 12; the single 5S rDNA cluster is also intercalary to the long arm of chromosome pair 4. While U2 snRNA gene clusters map to a single subcentromeric position on chromosome pair 13, U1 snRNA gene clusters seem to appear on almost all chromosome pairs, but showing bigger clusters on pairs 5, 13, 16, 17 and 19. The brightest signals on pair 13 are coincident with the single U2 snRNA gene cluster signals. Therefore, the use of these probes allows the unequivocal identification of at least 7 of the chromosome pairs that compose the karyotype of Merluccius merluccius thus opening the way to integrate molecular genetics and cytological data on the study of the genome of this important species.

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Chromosomal mapping of telomeric sequences to chromosomes of Merluccius merluccius.Metaphase plate of Merluccius merluccius stained with DAPI (a) and PI (b). Note that telomeric signals (green) appear only at the ends of the chromosomes. Scale bars, 5 μm.
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pone.0146150.g003: Chromosomal mapping of telomeric sequences to chromosomes of Merluccius merluccius.Metaphase plate of Merluccius merluccius stained with DAPI (a) and PI (b). Note that telomeric signals (green) appear only at the ends of the chromosomes. Scale bars, 5 μm.

Mentions: Telomeric sequences were detected using a vertebrate telomeric (CCCTAA)3 PNA probe. Single distinct terminal signals appear at the ends of both sister chromatids of every mitotic chromosome (Fig 3). No additional interstitial telomeric sequences were observed.


Molecular Cytogenetic Analysis of the European Hake Merluccius merluccius (Merlucciidae, Gadiformes): U1 and U2 snRNA Gene Clusters Map to the Same Location.

García-Souto D, Troncoso T, Pérez M, Pasantes JJ - PLoS ONE (2015)

Chromosomal mapping of telomeric sequences to chromosomes of Merluccius merluccius.Metaphase plate of Merluccius merluccius stained with DAPI (a) and PI (b). Note that telomeric signals (green) appear only at the ends of the chromosomes. Scale bars, 5 μm.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4696792&req=5

pone.0146150.g003: Chromosomal mapping of telomeric sequences to chromosomes of Merluccius merluccius.Metaphase plate of Merluccius merluccius stained with DAPI (a) and PI (b). Note that telomeric signals (green) appear only at the ends of the chromosomes. Scale bars, 5 μm.
Mentions: Telomeric sequences were detected using a vertebrate telomeric (CCCTAA)3 PNA probe. Single distinct terminal signals appear at the ends of both sister chromatids of every mitotic chromosome (Fig 3). No additional interstitial telomeric sequences were observed.

Bottom Line: Concerning rRNA genes, this species show a single 45S rDNA cluster at an intercalary location on the long arm of subtelocentric chromosome pair 12; the single 5S rDNA cluster is also intercalary to the long arm of chromosome pair 4.While U2 snRNA gene clusters map to a single subcentromeric position on chromosome pair 13, U1 snRNA gene clusters seem to appear on almost all chromosome pairs, but showing bigger clusters on pairs 5, 13, 16, 17 and 19.The brightest signals on pair 13 are coincident with the single U2 snRNA gene cluster signals.

View Article: PubMed Central - PubMed

Affiliation: Departamento de Bioquímica, Xenética e Inmunoloxía, Universidade de Vigo, Vigo, Spain.

ABSTRACT
The European hake (Merluccius merluccius) is a highly valuable and intensely fished species in which a long-term alive stock has been established in captivity for aquaculture purposes. Due to their huge economic importance, genetic studies on hakes were mostly focused on phylogenetic and phylogeographic aspects; however chromosome numbers are still not described for any of the fifteen species in the genus Merluccius. In this work we report a chromosome number of 2n = 42 and a karyotype composed of three meta/submetacentric and 18 subtelo/telocentric chromosome pairs. Telomeric sequences appear exclusively at both ends of every single chromosome. Concerning rRNA genes, this species show a single 45S rDNA cluster at an intercalary location on the long arm of subtelocentric chromosome pair 12; the single 5S rDNA cluster is also intercalary to the long arm of chromosome pair 4. While U2 snRNA gene clusters map to a single subcentromeric position on chromosome pair 13, U1 snRNA gene clusters seem to appear on almost all chromosome pairs, but showing bigger clusters on pairs 5, 13, 16, 17 and 19. The brightest signals on pair 13 are coincident with the single U2 snRNA gene cluster signals. Therefore, the use of these probes allows the unequivocal identification of at least 7 of the chromosome pairs that compose the karyotype of Merluccius merluccius thus opening the way to integrate molecular genetics and cytological data on the study of the genome of this important species.

Show MeSH