scholarly journals REGULATION OF RIBOSOMAL RNA AND 5s RNA SYNTHESIS IN DROSOPHILA MELANOGASTER: I. BOBBED MUTANTS

Genetics ◽  
1972 ◽  
Vol 72 (2) ◽  
pp. 267-276
Author(s):  
Roberto Weinmann
Keyword(s):  
Drosophila Melanogaster ◽  
Developmental Delay ◽  
Ribosomal Rna ◽  
Gel Electrophoresis ◽  
Rna Synthesis ◽  
Rrna Synthesis ◽  
Wild Type ◽  
5S Rna ◽  
Wild Type Level

ABSTRACT Analysis of the rates and amounts of rRNA and 5s RNA synthesized in Drosophila melanogaster bobbed mutants was done by using acrylamide-gel electrophoresis. The results show that the amounts of rRNA synthesized are constant, although the rates of rRNA synthesis in bb's are reduced to 30% of the wild-type level. The rates of synthesis of 5s RNA were constant. The rate of synthesis of the two kinds of molecules that enter in equimolar amounts into the mature ribosome is non-coordinated.—The rates of rRNA synthesis were shown to be proportional to the length of the scutellar bristles, supporting the notion that in trichogen cells there is no developmental delay, but the size of the bristle depends directly on the rate of rRNA synthesis.

scholarly journals DIFFERENTIATION OF DROSOPHILA CELLS LACKING RIBOSOMAL DNA, IN VITRO

Genetics ◽  
1973 ◽  
Vol 73 (3) ◽  
pp. 429-434
Author(s):  
J James Donady ◽  
R L Seecof ◽  
M A Fox
Keyword(s):  
Drosophila Melanogaster ◽  
Ribosomal Rna ◽  
Ribosomal Dna ◽  
Rna Synthesis ◽  
Wild Type ◽  
Drosophila Cells

ABSTRACT Drosophila melanogaster embryos that lacked ribosomal DNA were obtained from appropriate crosses. Cells were taken from such embryos before overt differentiation took place and were cultured in vitro. These cells differentiated into neurons and myocytes with the same success as did wild-type controls. Therefore, ribosomal RNA synthesis is not necessary for the differentiation of neurons and myocytes in vitro.

REGULATION OF RIBOSOMAL RNA GENE MULTIPLICITY IN DROSOPHILA MELANOGASTER

Genetics ◽  
1973 ◽  
Vol 73 (1) ◽  
pp. 57-71
Author(s):  
Kenneth D Tartof
Keyword(s):  
Drosophila Melanogaster ◽  
Ribosomal Rna ◽  
Homologous Chromosome ◽  
Germ Line ◽  
Rrna Genes ◽  
Rrna Gene ◽  
Wild Type ◽  
Wild Type Level ◽  
New Genotype ◽  
Successive Generations

ABSTRACT The ribosomal RNA (rRNA) genes of Drosophila melanogaster can undergo a disproportionate replication of their number. This occurs when the cluster of rRNA genes (rDNA) of one chromosome is maintained with a homologous chromosome that is completely or partially deficient in its rDNA. Under appropriate genetic conditions, it appears that disproportionate rDNA replication can be generated at the level of both somatic and germ line cells. In the latter case, mutants partially deficient for rDNA can increase their rRNA gene number to the wild type level and transmit this new genotype to successive generations.

scholarly journals GENETIC ANALYSIS OF THE 5S RNA GENES IN DROSOPHILA MELANOGASTER

Genetics ◽  
1975 ◽  
Vol 81 (3) ◽  
pp. 515-523
Author(s):  
James D Procunier ◽  
Kenneth D Tartof
Keyword(s):  
Drosophila Melanogaster ◽  
Ribosomal Rna ◽  
Organizer Region ◽  
Nucleolus Organizer Region ◽  
Ribosomal Rna Genes ◽  
Chromosome 2 ◽  
Wild Type ◽  
5S Rna ◽  
5S Rna Genes ◽  
Rna Genes

ABSTRACT The 5S RNA genes of Drosophila melanogaster in either an isogenic wild-type or a multiply inverted (SM1) chromosome 2 increase their multiplicity when opposite a deficiency for the 5S gene site. This is analogous to the compensation phenomenon previously described for the 18S and 28S ribosomal RNA genes of the X chromosome nucleolus organizer region. Molecular hybridization of 5S RNA to DNA containing various doses of the 56F1-9 region of chromosome 2 demonstrates that most, if not all, of the 5S genes reside in or near this region. Also, a deficiency missing approximately one-half of the wild-type number of 5S genes was isolated and genetically localized. This mutant has a phenotype like that of bobbed, a mutant known to be partially deficient in 18S and 28S ribosomal RNA genes. Finally, we report the existence of a chromosomal rearrangement which splits the second chromosome into two segments, each containing 5S DNA.

scholarly journals GENETIC MODULATION OF RNA METABOLISM IN DROSOPHILA. I. INCREASED RATE OF RIBOSOMAL RNA SYNTHESIS

Genetics ◽  
1977 ◽  
Vol 86 (4) ◽  
pp. 789-800
Author(s):  
Stephen H Clark ◽  
Linda D Strausbaugh ◽  
Barry I Kiefer
Keyword(s):  
Y Chromosome ◽  
Ribosomal Rna ◽  
Development Time ◽  
Rna Synthesis ◽  
Specific Activity ◽  
Rrna Synthesis ◽  
Adult Males ◽  
Wild Type ◽  
Wild Type Phenotype ◽  
Activity Measurements

ABSTRACT It has been suggested that a particular Y chromosome which is rDNA-deficient (YbbSuVar-5) may be associated with an increased utilization of rDNA template in adult testes (Shermoen and Kiefer 1975). To extend the observations on this chromosome, experiments were designed to determine if the chromosome has an effect on rRNA synthesis in bobbed adults and on classic bobbed phenotypes (shortened and thinner scutellar bristles and delayed development). Specific activity measurements were made on rRNA extracted from adult males of the genotypes car bb/Ybb- and car bb/YbbSuVar-5, which are rDNA-deficient to the same extent, and from Samarkand+ isogenic (Sam+ iso), which is a wild-type stock. The resulting data demonstrated that the presence of the YbbSuVar-5 chromosome increases the rate of ribosomal RNA synthesis in adult flies. In addition, it was found that the presence of this particular Y chromosome restores wild-type bristle phenotype and development time. Appropriate genetic crosses indicate that the observed effects (increased rRNA synthesis, restoration of wild-type phenotype) are a function of this particular Y chromosome, and are not due to autosomal factors. The results of these experiments suggest that the rate of rRNA accumulation is under genetic control.

scholarly journals Formation of an active transcription complex in the Drosophila melanogaster 5S RNA gene is dependent on an upstream region.

1987 ◽  
Vol 7 (6) ◽  
pp. 2046-2051 ◽  
Author(s):  
A D Garcia ◽  
A M O'Connell ◽  
S J Sharp
Keyword(s):  
Drosophila Melanogaster ◽  
Transcription Initiation ◽  
Rna Polymerase Iii ◽  
In Vitro Transcription ◽  
Upstream Region ◽  
Nucleotide Position ◽  
Wild Type ◽  
5S Rna ◽  
Cell Extracts

We constructed deletion-substitution and linker-scanning mutations in the 5'-flanking region of the Drosophila melanogaster 5S RNA gene. In vitro transcription of these templates in Drosophila and HeLa cell extracts revealed the presence of an essential control region (-30 region) located between nucleotides -39 and -26 upstream of the transcription initiation site: deletion of sequences upstream of nucleotide position -39 had no detectable effect on the wild-type level of in vitro transcription, whereas mutations extending between positions -39 and 1 resulted in templates with decreased transcriptional levels; specifically, deletion and linker-scanning mutations in the -34 to -26 region (-30 region) resulted in loss of transcription. The -30 region is essential for transcription and therefore forms part of the Drosophila 5S RNA gene transcription promoter. Compared with the activity of the wild-type gene, mutant 5S DNAs exhibited no impairment in the ability to sequester limiting transcription factors in a template exclusion competition assay. While we do not know which transcription factor(s) interacts with the -30 region, the possible involvement of RNA polymerase III at this region is discussed.

A Stable 44S Intermediate in the Autodigestion of 50S Ribosomal Subunits

1971 ◽  
Vol 29 ◽  
pp. 430-431
Author(s):  
John H. Nisbet ◽  
Henry S. Slayter
Keyword(s):  
Escherichia Coli ◽  
Molecular Weight ◽  
Ribosomal Rna ◽  
Gel Electrophoresis ◽  
Type Strain ◽  
Wild Type Strain ◽  
Ribosomal Subunit ◽  
Wild Type ◽  
Ribosomal Subunits ◽  
Type Strains

Wild - type strains of Escherichia coli are known to contain as many as four endogenous nucleases (Ref. 1). These are commonly found associated with the ribosomes after extraction from the cell, but may be removed, with the exception of RNase IV, by washing the ribosomes in NH4Cl (at 0.2 M and higher concentrations). We have examined the effect of these nucleases on the 50S ribosomal subunit of one wild-type strain, K12 (Hfr 3000), by incubating the unwashed particles at 37° in the presence of varying magnesium concentrations.At 10-4 molar magnesium (slower at 10-3 molar), the 50S particle is converted to a species sedimenting at about 44S. About 20% of the total O.D260 is liberated at the same time. Continued incubation leads to the release of more O.D260 material while the RNA remaining in the 44S (Fig. 1) particle is progressively cleaved, eventually to the point where it consists of one principal fragment of molecular weight 0.42 x 106 daltons and several lesser fragments. The ribosomal RNA and proteins have been characterized by acrylamide gel electrophoresis.

Studies On The Structure And Cellular Location Of Various Ribosome And Ribosomal Rna Species In The Green Alga Chlamydomonas Reinhardi

1971 ◽  
Vol 8 (1) ◽  
pp. 153-183 ◽  
Author(s):  
D. P. BOURQUE ◽  
J. E. BOYNTON ◽  
N. W. GILLHAM
Keyword(s):  
Ribosomal Rna ◽  
Gel Electrophoresis ◽  
Sucrose Gradient ◽  
Chlorophyll Synthesis ◽  
Sedimentation Velocity ◽  
Wild Type ◽  
Progressive Reduction ◽  
Lamellar System ◽  
Subunit Dissociation ◽  
Type C

Under ionic conditions effecting little or no subunit dissociation, Chlamydomonas reinhardi contains 2 major classes of ribosomes with generic sedimentation velocities of 83 and 70s and 3 minor classes with sedimentation velocities of 66, 54, and 41s. Ribosomal RNAs with sedimentation velocities of 25, 23, 18, 16 and 5s have been identified. The 70-s ribosomes are in the chloroplast and contain 23-, 16- and 5-s ribosomal RNA whereas the 83-s ribosomes are in the cytoplasm and contain 25-, 18- and 5-s ribosomal RNA. Numbers of chloroplast ribosome particles counted in electron micrographs of wild type C. reinhardi and the ac-20 and y mutants have been compared with relative amounts of 70-s ribosomes determined by sucrose gradient sedimentation and amounts of 23-, 16- and 5-s ribosomal RNA determined by gel electrophoresis. In response to reduced concentrations of magnesium the 70-s ribosomes of wild type are susceptible to a progressive reduction in sedimentation velocity whereas the 66-s ribosomes of the mutant ac-20 are not. Chlorophyll synthesis and the formation of the chloroplast lamellar system do not appear to be correlated with the relative amounts of chloroplast ribosomes.

Formation of an active transcription complex in the Drosophila melanogaster 5S RNA gene is dependent on an upstream region

1987 ◽  
Vol 7 (6) ◽  
pp. 2046-2051
Author(s):  
A D Garcia ◽  
A M O'Connell ◽  
S J Sharp
Keyword(s):  
Drosophila Melanogaster ◽  
Transcription Initiation ◽  
Rna Polymerase Iii ◽  
In Vitro Transcription ◽  
Upstream Region ◽  
Nucleotide Position ◽  
Wild Type ◽  
5S Rna ◽  
Cell Extracts

We constructed deletion-substitution and linker-scanning mutations in the 5'-flanking region of the Drosophila melanogaster 5S RNA gene. In vitro transcription of these templates in Drosophila and HeLa cell extracts revealed the presence of an essential control region (-30 region) located between nucleotides -39 and -26 upstream of the transcription initiation site: deletion of sequences upstream of nucleotide position -39 had no detectable effect on the wild-type level of in vitro transcription, whereas mutations extending between positions -39 and 1 resulted in templates with decreased transcriptional levels; specifically, deletion and linker-scanning mutations in the -34 to -26 region (-30 region) resulted in loss of transcription. The -30 region is essential for transcription and therefore forms part of the Drosophila 5S RNA gene transcription promoter. Compared with the activity of the wild-type gene, mutant 5S DNAs exhibited no impairment in the ability to sequester limiting transcription factors in a template exclusion competition assay. While we do not know which transcription factor(s) interacts with the -30 region, the possible involvement of RNA polymerase III at this region is discussed.

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