Limits...
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.

Show MeSH
Chromosomal mapping of rRNA and U2 snRNA genes to chromosomes of Merluccius merluccius.Double-FISH experiments using a 28S rDNA probe (green) and a 5S rDNA probe (red) demonstrate the presence of a single clusters for both 45S and 5S rRNA genes on different chromosome pairs (a). Rehybridization of the same metaphases with an U2 snDNA probe (violet) also give signals at a single location on a different chromosome pair (a). The corresponding karyotype shows these signals on chromosome pairs 12, 4 and 13, respectively (b). Chromosomes are counterstained with DAPI. Scale bars, 5 μm.
© Copyright Policy
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4696792&req=5

pone.0146150.g001: Chromosomal mapping of rRNA and U2 snRNA genes to chromosomes of Merluccius merluccius.Double-FISH experiments using a 28S rDNA probe (green) and a 5S rDNA probe (red) demonstrate the presence of a single clusters for both 45S and 5S rRNA genes on different chromosome pairs (a). Rehybridization of the same metaphases with an U2 snDNA probe (violet) also give signals at a single location on a different chromosome pair (a). The corresponding karyotype shows these signals on chromosome pairs 12, 4 and 13, respectively (b). Chromosomes are counterstained with DAPI. Scale bars, 5 μm.

Mentions: A diploid chromosome number of 2n = 42 was determined for the European hake Merluccius merluccius after analyzing 400 metaphase plates belonging to 20 larvae and 20 adults (10 females and 10 males) (Figs 1 and 2). The karyotype is composed by three meta/submetacentric and 18 subtelo/telocentric chromosome pairs. No differences were detected among karyotypes from males and females neither from larvae and adults nor from individuals collected at different places.


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 rRNA and U2 snRNA genes to chromosomes of Merluccius merluccius.Double-FISH experiments using a 28S rDNA probe (green) and a 5S rDNA probe (red) demonstrate the presence of a single clusters for both 45S and 5S rRNA genes on different chromosome pairs (a). Rehybridization of the same metaphases with an U2 snDNA probe (violet) also give signals at a single location on a different chromosome pair (a). The corresponding karyotype shows these signals on chromosome pairs 12, 4 and 13, respectively (b). Chromosomes are counterstained with DAPI. Scale bars, 5 μm.
© Copyright Policy
Related In: Results  -  Collection

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

pone.0146150.g001: Chromosomal mapping of rRNA and U2 snRNA genes to chromosomes of Merluccius merluccius.Double-FISH experiments using a 28S rDNA probe (green) and a 5S rDNA probe (red) demonstrate the presence of a single clusters for both 45S and 5S rRNA genes on different chromosome pairs (a). Rehybridization of the same metaphases with an U2 snDNA probe (violet) also give signals at a single location on a different chromosome pair (a). The corresponding karyotype shows these signals on chromosome pairs 12, 4 and 13, respectively (b). Chromosomes are counterstained with DAPI. Scale bars, 5 μm.
Mentions: A diploid chromosome number of 2n = 42 was determined for the European hake Merluccius merluccius after analyzing 400 metaphase plates belonging to 20 larvae and 20 adults (10 females and 10 males) (Figs 1 and 2). The karyotype is composed by three meta/submetacentric and 18 subtelo/telocentric chromosome pairs. No differences were detected among karyotypes from males and females neither from larvae and adults nor from individuals collected at different places.

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