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Ribosomal RNA gene silencing in interpopulation hybrids of Tigriopus californicus: nucleolar dominance in the absence of intergenic spacer subrepeats.
Flowers JM
,
Burton RS
.
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A common feature of interspecific animal and plant hybrids is the uniparental silencing of ribosomal RNA gene transcription, or nucleolar dominance. A leading explanation for the genetic basis of nucleolar dominance in animal hybrids is the enhancer-imbalance model. The model proposes that limiting transcription factors are titrated by a greater number of enhancer-bearing subrepeat elements in the intergenic spacer (IGS) of the dominant cluster of genes. The importance of subrepeats for nucleolar dominance has repeatedly been supported in competition assays between Xenopus laevis and X. borealis minigene constructs injected into oocytes. However, a more general test of the importance of IGS subrepeats for nuclear dominance in vivo has not been conducted. In this report, rRNA gene expression was examined in interpopulation hybrids of the marine copepod Tigriopus californicus. This species offers a rare opportunity to test the role of IGS subrepeats in nucleolar dominance because the internal subrepeat structure, found in the IGS of virtually all animal and plant species, is absent in T. californicus. Our results clearly establish that nucleolar dominance occurs in F1 and F2 interpopulation hybrids of this species. In the F2 generation, nucleolar dominance appears to break down in some hybrids in a fashion that is inconsistent with a transcription factor titration model. These results are significant because they indicate that nucleolar dominance can be established and maintained without enhancer-bearing repeat elements in the IGS. This challenges the generality of the enhancer-imbalance model for nucleolar dominance and suggests that dominance of rRNA transcription in animals may be determined by epigenetic factors as has been established in plants.
Bernard,
Integrated amplification and detection of the C677T point mutation in the methylenetetrahydrofolate reductase gene by fluorescence resonance energy transfer and probe melting curves.
1998, Pubmed
Bernard,
Integrated amplification and detection of the C677T point mutation in the methylenetetrahydrofolate reductase gene by fluorescence resonance energy transfer and probe melting curves.
1998,
Pubmed
Blackler,
Transmission of sex cells of one species through the body of a second species in the genus Xenopus. II. Interspecific matings.
1972,
Pubmed
,
Xenbase
Burton,
Nuclear and mitochondrial gene genealogies and allozyme polymorphism across a major phylogeographic break in the copepod Tigriopus californicus.
1994,
Pubmed
Burton,
Unusual structure of ribosomal DNA in the copepod Tigriopus californicus: intergenic spacer sequences lack internal subrepeats.
2005,
Pubmed
Burton,
POPULATION GENETICS OF TIGRIOPUS CALIFORNICUS. II. DIFFERENTIATION AMONG NEIGHBORING POPULATIONS.
1981,
Pubmed
Burton,
HYBRID BREAKDOWN IN DEVELOPMENTAL TIME IN THE COPEPOD TIGRIOPUS CALIFORNICUS.
1990,
Pubmed
Busby,
Spacer sequences regulate transcription of ribosomal gene plasmids injected into Xenopus embryos.
1983,
Pubmed
,
Xenbase
Caudy,
Xenopus ribosomal RNA gene intergenic spacer elements conferring transcriptional enhancement and nucleolar dominance-like competition in oocytes.
2002,
Pubmed
,
Xenbase
Chen,
Epigenetic silencing of RNA polymerase I transcription: a role for DNA methylation and histone modification in nucleolar dominance.
1997,
Pubmed
Chen,
Gene dosage and stochastic effects determine the severity and direction of uniparental ribosomal RNA gene silencing (nucleolar dominance) in Arabidopsis allopolyploids.
1998,
Pubmed
Durica,
Studies on the ribosomal RNA cistrons in interspecific Drosophila hybrids. I. Nucleolar dominance.
1977,
Pubmed
Durica,
Studies on the Ribosomal RNA Cistrons in Interspecific Drosophila Hybrids. II. Heterochromatic Regions Mediating Nucleolar Dominance.
1978,
Pubmed
Edmands,
Phylogeography of the intertidal copepod Tigriopus californicus reveals substantially reduced population differentiation at northern latitudes.
2001,
Pubmed
Edmands,
Genetic consequences of many generations of hybridization between divergent copepod populations.
2005,
Pubmed
Edmands,
HETEROSIS AND OUTBREEDING DEPRESSION IN INTERPOPULATION CROSSES SPANNING A WIDE RANGE OF DIVERGENCE.
1999,
Pubmed
Frieman,
RNA polymerase I transcription in a Brassica interspecific hybrid and its progenitors: Tests of transcription factor involvement in nucleolar dominance.
1999,
Pubmed
Goodrich-Young,
Nucleolar dominance and replicative dominance in Drosophila interspecific hybrids.
1989,
Pubmed
Grimaldi,
Multiple repeated units in Drosophila melanogaster ribosomal DNA spacer stimulate rRNA precursor transcription.
1988,
Pubmed
Grummt,
Epigenetic silencing of RNA polymerase I transcription.
2003,
Pubmed
Grummt,
Ribosomal RNA transcription in vitro is species specific.
1982,
Pubmed
Grummt,
Life on a planet of its own: regulation of RNA polymerase I transcription in the nucleolus.
2003,
Pubmed
Honjo,
Preferential transcription of Xenopus laevis ribosomal RNA in interspecies hybrids between Xenopus laevis and Xenopus mulleri.
1973,
Pubmed
,
Xenbase
Kohorn,
Accurate transcription of truncated ribosomal DNA templates in a Drosophila cell-free system.
1982,
Pubmed
Kuhn,
A 140-base-pair repetitive sequence element in the mouse rRNA gene spacer enhances transcription by RNA polymerase I in a cell-free system.
1990,
Pubmed
,
Xenbase
Labhart,
Enhancer-like properties of the 60/81 bp elements in the ribosomal gene spacer of Xenopus laevis.
1984,
Pubmed
,
Xenbase
Lawrence,
A concerted DNA methylation/histone methylation switch regulates rRNA gene dosage control and nucleolar dominance.
2004,
Pubmed
Lewis,
Evidence for nucleolus organizer regions as the units of regulation in nucleolar dominance in Arabidopsis thaliana interecotype hybrids.
2004,
Pubmed
Long,
Repeated genes in eukaryotes.
1980,
Pubmed
,
Xenbase
Lyon,
Quantification of HER2/neu gene amplification by competitive pcr using fluorescent melting curve analysis.
2001,
Pubmed
Miesfeld,
The absence of a human-specific ribosomal DNA transcription factor leads to nucleolar dominance in mouse greater than human hybrid cells.
1984,
Pubmed
Pape,
The Xenopus ribosomal DNA 60- and 81-base-pair repeats are position-dependent enhancers that function at the establishment of the preinitiation complex: analysis in vivo and in an enhancer-responsive in vitro system.
1989,
Pubmed
,
Xenbase
Pikaard,
Nucleolar dominance: uniparental gene silencing on a multi-megabase scale in genetic hybrids.
2000,
Pubmed
Pikaard,
The epigenetics of nucleolar dominance.
2000,
Pubmed
Reeder,
Mechanisms of nucleolar dominance in animals and plants.
1985,
Pubmed
Reeder,
rRNA synthesis in the nucleolus.
1990,
Pubmed
Reeder,
The mechanism of nucleolar dominance in Xenopus hybrids.
1984,
Pubmed
,
Xenbase
Voordouw,
Heritability of sex tendency in a harpacticoid copepod, Tigriopus californicus.
2002,
Pubmed
