Results 221 to 230 of about 317,056 (255)

The ribosomal DNA of Calliphora erythrocephala; an analysis of hybrid plasmids containing ribosomal DNA

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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Synthesis of ribosomal DNA in conjugating Tetrahymena

Experimental Cell Research, 1979
Abstract 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, P, Andersson, J, Engberg, J R, Nilsson   +3 more
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Natural selection and ribosomal DNA in Drosophila

Genome, 1989
Natural 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, H, Hollocher, S, Lawler, J S, Johnston   +3 more
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The evolution of eukaryotic ribosomal DNA

Biosystems, 1986
Mutations 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, 1996
Ribosomal 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, Bourget, Nathalie, Decaris, Bernard   +2 more
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Ribosomal DNA in Maize

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, M. D. McMullen, S. Enomoto, I. Rubenstein   +3 more
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Ribosomal DNA instability and genome adaptability

Chromosome Research, 2019
Ribosomes 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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Ribosomal DNA in spores of Physarum polycephalum

Biochimica et Biophysica Acta (BBA) - Nucleic Acids and Protein Synthesis, 1978
DNA was isolated from plasmodia, spores and newly hatched amoebae of the slime mould Physarum polycephalum. The DNA preparations were fractionated in CsCl gradients and each fraction hybridised to combined 19 S + 26 S rRNA. In all three DNA preparations hybridisation was found to be limited to satellite DNA (rho = 1.714 g/cm3) and at saturation was ...
H U, Affolter, R, Braun
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The replication of ribosomal DNA in the macronucleus of Tetrahymena

Chromosoma, 1977
The replication of extrachromosomal rDNA molecules from the macronucleus of Tetrahymena was studied by electron microscopy. Replication begins in the center of the palindromic molecule and proceeds by means of bidirectional fork movement toward the free ends of the molecule.
M A, Truett, J G, Gall
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Structure of ribosomal DNA in Physarum polycephalum

Journal of Molecular Biology, 1976
Abstract The sequences coding for Physarum ribosomal RNA are localized on idependently replicating, linear DNA molecules of a discrete size, M r = 37 × 10 6 . Restriction endonucleases Eco RI and Hin dIII each cut ribosomal DNA into one large and two small fragments.
V M, Vogt, R, Braun
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