Results 271 to 280 of about 338,742 (309)
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The Ribosomal DNA Plasmids of Entamoeba
Parasitology Today, 1998In most organisms, the nuclear ribosomal RNA (rRNA) genes are highly repetitive and arranged as tandem repeats on one or more chromosomes. In Entamoeba, however, these genes are located almost exclusively on extrachromosomal circular DNA molecules with no clear evidence so far of a chromosomal copy.
S, Bhattacharya, I, Som, A, Bhattacharya
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Ribosomal DNA of Caenorhabditis elegans
Journal of Molecular Biology, 1981Abstract We have characterized the organization of the genes coding for 18 S, 5·8 S and 26 S ribosomal RNAs in the nematode Caenorhabditis elegans . These ribosomal genes, present in about 55 copies per haploid genome, alternate in a repeating tandem array.
J G, Files, D, Hirsh
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Journal of Molecular Biology, 1980
Abstract We have analysed the ribosomal DNA of Calliphora erythrocephala, a Dipteran fly of the same sub-order as Drosophila melanogaster, through a series of rDNA † fragments cloned in a plasmid vector. We have mapped the sites for eight restriction enzymes within these plasmids, and positioned the regions coding for the 18 S and 28 S rRNAs within ...
K, Beckingham, R, White
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Abstract We have analysed the ribosomal DNA of Calliphora erythrocephala, a Dipteran fly of the same sub-order as Drosophila melanogaster, through a series of rDNA † fragments cloned in a plasmid vector. We have mapped the sites for eight restriction enzymes within these plasmids, and positioned the regions coding for the 18 S and 28 S rRNAs within ...
K, Beckingham, R, White
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Ribosomal DNA and Neurological Disorders
Current Molecular MedicineRibosomal DNA (rDNA) is important in the nucleolus and nuclear organization of human cells. Defective rDNA repeat maintenance has been reported to be closely associated with neurological disorders, such as Alzheimer’s disease, Huntington’s disease, Parkinson’s disease, amyotrophic lateral sclerosis, frontotemporal dementia, depression, suicide, etc ...
Hong Zhou +6 more
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Synthesis of ribosomal DNA in conjugating Tetrahymena
Experimental Cell Research, 1979Abstract In the ciliate protozoan Tetrahymena thermophila, a single integrated gene coding for ribosomal RNA in the micronucleus is amplified during the sexual cycle to yield many copies of extrachromosomal palindromic rDNA in the macronucleus. Hybridization of newly synthesized DNA with rRNA has shown that extensive rDNA synthesis takes place early ...
R E, Pearlman +3 more
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Natural selection and ribosomal DNA in Drosophila
Genome, 1989Natural populations of Drosophila mercatorum are variable for the number of X-linked 28S ribosomal genes bearing a 5-kilobase insert. A separate polymorphic X-linked gene controls whether 28S repeats bearing the insert are preferentially underreplicated during the formation of polytene tissue.
A R, Templeton +3 more
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The evolution of eukaryotic ribosomal DNA
Biosystems, 1986Mutations occur randomly throughout the ribosomal DNA (rDNA) sequence. Molecular drive (unequal crossing-over, gene conversion, and transposition) spreads these variations through the multiple copies of rDNA. Forces of selection act upon the variants to favor and fix them or disfavor and eliminate them.
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Ribosomal DNA polymorphism in the genus Bifidobacterium
Research in Microbiology, 1996Ribosomal DNA polymorphism was studied in order to demonstrate intra- and interspecies differentiation of 42 Bifidobacterium strains. DNA from these strains was digested with the endonucleases BamHI, EcoRV, HindIII and PvuII and then analysed by Southern blotting. Ribosomal patterns using a part of an rRNA 23S gene as a probe clearly differentiated the
Mangin, Irène +2 more
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Ribosomal DNA instability and genome adaptability
Chromosome Research, 2019Ribosomes are large, multi-subunit ribonucleoprotein complexes, essential for protein synthesis. To meet the high cellular demand for ribosomes, all eukaryotes have numerous copies of ribosomal DNA (rDNA) genes that encode ribosomal RNA (rRNA), usually far in excess of the requirement for ribosome biogenesis.
Devika, Salim, Jennifer L, Gerton
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1988
The nucleolus organizer region (NOR) of maize chromosome 6 is now known to be the location of the 17/5.8/26S rDNA (hereafter termed 17/26S rDNA); this molecular information extends the NOR function to one of synthesizer as well as organizer. The extensive variation in ribosomal DNA (rDNA) multiplicity and the finding that much of the rDNA is in the NOR-
R. L. Phillips +3 more
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The nucleolus organizer region (NOR) of maize chromosome 6 is now known to be the location of the 17/5.8/26S rDNA (hereafter termed 17/26S rDNA); this molecular information extends the NOR function to one of synthesizer as well as organizer. The extensive variation in ribosomal DNA (rDNA) multiplicity and the finding that much of the rDNA is in the NOR-
R. L. Phillips +3 more
openaire +1 more source