Early evolutionary colocalization of the nuclear ribosomal 5S and 45S gene families in seed plants: evidence from the living fossil gymnosperm Ginkgo biloba

In seed plants, the colocalization of the 5S loci within the intergenic spacer (IGS) of the nuclear 45S tandem units is restricted to the phylogenetically derived Asteraceae family. However, fluorescent in situ hybridization (FISH) colocalization of both multigene families has also been observed in...

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Detalhes bibliográficos
Autores: Galián, José, Rosato, Carmen Luisa Marcela, Rosselló, Josep
Formato: artículo
Fecha de publicación:2012
País:España
Recursos:Universidad Complutense de Madrid (UCM)
Repositorio:Docta Complutense
Idioma:inglés
OAI Identifier:oai:docta.ucm.es:20.500.14352/95248
Acesso em linha:https://hdl.handle.net/20.500.14352/95248
Access Level:acceso abierto
Palavra-chave:575.113
rDNA
Intergenic spacer
45S–5S unit
Ribosomal pseudogenes gymnosperm
Phylogenetic relict
Genética
2409 Genética
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spelling Early evolutionary colocalization of the nuclear ribosomal 5S and 45S gene families in seed plants: evidence from the living fossil gymnosperm Ginkgo bilobaGalián, JoséRosato, Carmen Luisa MarcelaRosselló, Josep575.113rDNAIntergenic spacer45S–5S unitRibosomal pseudogenes gymnospermPhylogenetic relictGenética2409 GenéticaIn seed plants, the colocalization of the 5S loci within the intergenic spacer (IGS) of the nuclear 45S tandem units is restricted to the phylogenetically derived Asteraceae family. However, fluorescent in situ hybridization (FISH) colocalization of both multigene families has also been observed in other unrelated seed plant lineages. Previous work has identified colocalization of 45S and 5S loci in Ginkgo biloba using FISH, but these observations have not been confirmed recently by sequencing a 1.8 kb IGS. In this work, we report the presence of the 45S-5S linkage in G. biloba, suggesting that in seed plants the molecular events leading to the restructuring of the ribosomal loci are much older than estimated previously. We obtained a 6.0 kb IGS fragment showing structural features of functional sequences, and a single copy of the 5S gene was inserted in the same direction of transcription as the ribosomal RNA genes. We also obtained a 1.8 kb IGS that was a truncate variant of the 6.0 kb IGS lacking the 5S gene. Several lines of evidence strongly suggest that the 1.8 kb variants are pseudogenes that are present exclusively on the satellite chromosomes bearing the 45S-5S genes. The presence of ribosomal IGS pseudogenes best reconciles contradictory results concerning the presence or absence of the 45S-5S linkage in Ginkgo. Our finding that both ribosomal gene families have been unified to a single 45S-5S unit in Ginkgo indicates that an accurate reassessment of the organization of rDNA genes in basal seed plants is necessary.NatureUniversidad Complutense de Madrid20122012-01-0120122012-01-01journal articlehttp://purl.org/coar/resource_type/c_6501VoRhttp://purl.org/coar/version/c_970fb48d4fbd8a85info:eu-repo/semantics/articleapplication/pdfhttps://hdl.handle.net/20.500.14352/95248reponame:Docta Complutenseinstname:Universidad Complutense de Madrid (UCM)Inglésengopen accesshttp://purl.org/coar/access_right/c_abf2info:eu-repo/semantics/openAccessoai:docta.ucm.es:20.500.14352/952482026-06-02T12:44:21Z
dc.title.none.fl_str_mv Early evolutionary colocalization of the nuclear ribosomal 5S and 45S gene families in seed plants: evidence from the living fossil gymnosperm Ginkgo biloba
title Early evolutionary colocalization of the nuclear ribosomal 5S and 45S gene families in seed plants: evidence from the living fossil gymnosperm Ginkgo biloba
spellingShingle Early evolutionary colocalization of the nuclear ribosomal 5S and 45S gene families in seed plants: evidence from the living fossil gymnosperm Ginkgo biloba
Galián, José
575.113
rDNA
Intergenic spacer
45S–5S unit
Ribosomal pseudogenes gymnosperm
Phylogenetic relict
Genética
2409 Genética
title_short Early evolutionary colocalization of the nuclear ribosomal 5S and 45S gene families in seed plants: evidence from the living fossil gymnosperm Ginkgo biloba
title_full Early evolutionary colocalization of the nuclear ribosomal 5S and 45S gene families in seed plants: evidence from the living fossil gymnosperm Ginkgo biloba
title_fullStr Early evolutionary colocalization of the nuclear ribosomal 5S and 45S gene families in seed plants: evidence from the living fossil gymnosperm Ginkgo biloba
title_full_unstemmed Early evolutionary colocalization of the nuclear ribosomal 5S and 45S gene families in seed plants: evidence from the living fossil gymnosperm Ginkgo biloba
title_sort Early evolutionary colocalization of the nuclear ribosomal 5S and 45S gene families in seed plants: evidence from the living fossil gymnosperm Ginkgo biloba
dc.creator.none.fl_str_mv Galián, José
Rosato, Carmen Luisa Marcela
Rosselló, Josep
author Galián, José
author_facet Galián, José
Rosato, Carmen Luisa Marcela
Rosselló, Josep
author_role author
author2 Rosato, Carmen Luisa Marcela
Rosselló, Josep
author2_role author
author
dc.contributor.none.fl_str_mv Universidad Complutense de Madrid
dc.subject.none.fl_str_mv 575.113
rDNA
Intergenic spacer
45S–5S unit
Ribosomal pseudogenes gymnosperm
Phylogenetic relict
Genética
2409 Genética
topic 575.113
rDNA
Intergenic spacer
45S–5S unit
Ribosomal pseudogenes gymnosperm
Phylogenetic relict
Genética
2409 Genética
description In seed plants, the colocalization of the 5S loci within the intergenic spacer (IGS) of the nuclear 45S tandem units is restricted to the phylogenetically derived Asteraceae family. However, fluorescent in situ hybridization (FISH) colocalization of both multigene families has also been observed in other unrelated seed plant lineages. Previous work has identified colocalization of 45S and 5S loci in Ginkgo biloba using FISH, but these observations have not been confirmed recently by sequencing a 1.8 kb IGS. In this work, we report the presence of the 45S-5S linkage in G. biloba, suggesting that in seed plants the molecular events leading to the restructuring of the ribosomal loci are much older than estimated previously. We obtained a 6.0 kb IGS fragment showing structural features of functional sequences, and a single copy of the 5S gene was inserted in the same direction of transcription as the ribosomal RNA genes. We also obtained a 1.8 kb IGS that was a truncate variant of the 6.0 kb IGS lacking the 5S gene. Several lines of evidence strongly suggest that the 1.8 kb variants are pseudogenes that are present exclusively on the satellite chromosomes bearing the 45S-5S genes. The presence of ribosomal IGS pseudogenes best reconciles contradictory results concerning the presence or absence of the 45S-5S linkage in Ginkgo. Our finding that both ribosomal gene families have been unified to a single 45S-5S unit in Ginkgo indicates that an accurate reassessment of the organization of rDNA genes in basal seed plants is necessary.
publishDate 2012
dc.date.none.fl_str_mv 2012
2012-01-01
2012
2012-01-01
dc.type.none.fl_str_mv journal article
http://purl.org/coar/resource_type/c_6501
VoR
http://purl.org/coar/version/c_970fb48d4fbd8a85
dc.type.openaire.fl_str_mv info:eu-repo/semantics/article
format article
dc.identifier.none.fl_str_mv https://hdl.handle.net/20.500.14352/95248
url https://hdl.handle.net/20.500.14352/95248
dc.language.none.fl_str_mv Inglés
eng
language_invalid_str_mv Inglés
language eng
dc.rights.none.fl_str_mv open access
http://purl.org/coar/access_right/c_abf2
dc.rights.openaire.fl_str_mv info:eu-repo/semantics/openAccess
rights_invalid_str_mv open access
http://purl.org/coar/access_right/c_abf2
eu_rights_str_mv openAccess
dc.format.none.fl_str_mv application/pdf
dc.publisher.none.fl_str_mv Nature
publisher.none.fl_str_mv Nature
dc.source.none.fl_str_mv reponame:Docta Complutense
instname:Universidad Complutense de Madrid (UCM)
instname_str Universidad Complutense de Madrid (UCM)
reponame_str Docta Complutense
collection Docta Complutense
repository.name.fl_str_mv
repository.mail.fl_str_mv
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score 15,812455

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