Allocycly and nucleolar dominance in Hordeum × Secale amphiploid somatic metaphases
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چکیده
منابع مشابه
Nucleolar dominance and replicative dominance in Drosophila interspecific hybrids.
The replication of the rDNA complement of only one nucleolus organizer region during polytene chromosome formation (replicative dominance) was initially observed in Drosophila melanogaster. Here we demonstrate replicative dominance in Drosophila simulans and D. melanogaster/D. simulans interspecific hybrids. A second nucleolar phenomenon, nucleolar dominance, is observed in the diploid tissue o...
متن کاملNucleolar dominance and ribosomal RNA gene silencing.
Nucleolar dominance is an epigenetic phenomenon that occurs in genetic hybrids and describes the expression of 45S rRNA genes inherited from one progenitor due to the silencing of the other progenitor's rRNA genes. Nucleolar dominance is a manifestation of rRNA gene dosage control, which also occurs in non-hybrids, regulating the number of active rRNA genes according to the cellular demand for ...
متن کاملRestricted chromosomal silencing in nucleolar dominance.
Failure of one parent's chromosomes to organize nucleoli in an interspecific hybrid is an epigenetic phenomenon known as nucleolar dominance. Selective gene silencing on a scale of millions of bp is known to be involved, but the full extent to which nucleolus organizer region (NOR)-bearing chromosomes are inactivated beyond the NORs is unknown. Aided by genome sequence data for Arabidopsis thal...
متن کاملNucleolar dominance and silencing of transcription.
Nucleolar dominance is a phenomenon in plant and animal hybrids whereby one parental set of ribosomal RNA (rRNA) genes is transcribed, but the hundreds of rRNA genes inherited from the other parent are silent. The phenomenon gets it name because only transcriptionally active rRNA genes give rise to a nucleolus, the site of ribosome assembly. Nucleolar dominance provided the first clear example ...
متن کاملMechanisms of nucleolar dominance in animals and plants
In interspecific hybrids, it is often observed that the ribosomal genes of one species are transcriptionally dominant over the ribosomal genes of the other species. This phenomenon has been called "nucleolar dominance" and has been reported in such diverse organisms as frogs (Xenopus), Drosophila, many genera of plants, and mammalian somatic cell hybrids. Recent advances in our knowledge of the...
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ژورنال
عنوان ژورنال: Hereditas
سال: 2008
ISSN: 0018-0661
DOI: 10.1111/j.1601-5223.1989.tb00380.x