Group fractionation and determination of the number of ribosomal subunit proteins from Drosophila melanogaster embryos

Biochemistry ◽  
1980 ◽  
Vol 19 (7) ◽  
pp. 1425-1433 ◽  
Author(s):  
W. Yean Chooi ◽  
Linda M. Sabatini ◽  
Elizabeth Dolliver ◽  
Michael Macklin ◽  
Dean Fraser
2018 ◽  
Vol 13 (4) ◽  
Author(s):  
Sibele Marques Bolson ◽  
Rodrigo Paidano Alves ◽  
Filipe De Carvalho Victoria ◽  
Kaenara Gomes Munhoz ◽  
Jeferson Luis Franco ◽  
...  

1994 ◽  
Vol 63 (2) ◽  
pp. 139-144 ◽  
Author(s):  
Sergey V. Nuzhdin ◽  
Trudy F. C. Mackay

SummaryRates of transposition and excision of the Drosophila melanogaster retrotransposon elements mdg3, 297, Doc, roo and copia were estimated directly, by in situ hybridization analysis of their cytological insertion sites in 31 replicates of a highly inbred line that had accumulated spontaneous mutations for approximately 160generations. Estimated transposition rates of Doc, roo and copia were, respectively, 4·2 × 10−5, 3·1 × 10−3 and 1·3 − 10−3; no transpositions of 297 nor mdg3 were observed. Rates of transposition of copia varied significantly among sublines. Excisions were only observed for roo elements, at a rate of 9·0 × 10−6 per element per generation. Copy number averaged over these element families increased 5·9 %; therefore, in these lines the magnitude of the forces opposing transposable element multiplication were weaker than transposition rates.


1968 ◽  
Vol 23 (4) ◽  
pp. 547-554 ◽  
Author(s):  
Dieter Eichelberg

This paper concerns with the quantitative determination of ommochrome precursors in the Malpighian tubes of Drosophila melanogaster during the individual development. After separation by paper chromatography the amounts of tryptophane, kynurenine and 3-hydroxykynurenine have been estimated by a spectrophotometer. The concentrations of these three substances obtained from wild-type Malpighian tubes have been compared with the quantities of the mutants brown (bw) and red Malpighian tubes (red). During development there are significant variabilities in contents of tryptophane, kynurenine and 3-hydroxykynurenine in the Malpighian tubes. In the larval tubes large quantities of ommochrome precursors are accumulated. With the beginning of metamorphosis there is a distinct decrease in these substances. After hatching the amount increases steadily until reaching a constant level. In the Malpighian tubes there are also sex differences: in females the concentration of kynurenine and 3-hydroxykynurenine is higher than in males. The results obtained from the mutants brown and red Malpighian tubes are on principle the same as those obtained from wild-type. A strong reduction of kynurenine contents is found in the mutant red Malpighian tubes. Perhaps in this mutant the kynurenine-hydroxilase-activity is lower than in wild-type. The amounts of ommochrome precursors, accumulated in the larval Malpighian tubes, do not correspond in all cases to the contents of xanthommatine formed in the eyes of the adults.


1957 ◽  
Vol 66 (4) ◽  
pp. 339-359 ◽  
Author(s):  
James H. Sang

SynopsisDrosophila melanogaster larvæ when cultured aseptically on a synthetic diet require exogenous ribose nucleic acid (RNA) for normal growth even though they can synthesize their own endogenous RNA from simple precursors. The optimum dietary supply lies between 0.4 and 0.7 per cent RNA. Individual bases, nucleosides and nucleotides which make up RNA cannot substitute for the whole polynucleotide, but adenine, adenosine, adenylic acid, guanosine and guanylic acid are used and stimulate growth to varying degrees. The pyrimidines and their nucleosides and nucleotides are not used when fed singly.It is shown that the de novo synthesis of purines may be more difficult than that of pyrimidines, and that if a source of purines is supplied (as adenylic acid), then the nucleosides and nucleotides of both cytosine and uracil are utilized by the larvæ, whereas the free bases are not. Cytidylic and uridylic acids seem to be interchangeable, and together with an adequate supply of adenylic acid give as good growth as RNA. Orotic acid and 2—6-diaminopurine are not used by the larvæ under the conditions described, but hypoxanthine and inosine are: xanthine and xanthosine can also be shown to have an effect on growth.Dose-response curves were determined for adenylic, guanylic, cytidylic and uridylic acids under conditions which allow the determination of the optimal supplies of each. These are found to be about 0.110, 0.080, 0.025 and 0.025 per cent, respectively. The requirement of RNA is therefore primarily a requirement of adenylic acid, since more than enough of the other nucleotides should be available when the supply of RNA is optimal. The optimal supply of adenine corresponds almost exactly with the optimal supply of adenylic acid, though a somewhat delayed larval development may be a result of energy utilization in the base-nucleoside-nucleotide conversion.These results are discussed in the light of our knowledge of purine and pyrimidine utilization in other multicellular organisms, particularly the rat, and possible applications of the findings are considered.


Genetics ◽  
1972 ◽  
Vol 71 (1) ◽  
pp. 139-156
Author(s):  
B H Judd ◽  
M W Shen ◽  
T C Kaufman

ABSTRACT An average size chromomere of the polytene X chromosome of Drosophila melanogaster contains enough DNA in each haploid equivalent strand to code for 30 genes, each 1,000 nucleotides long. We have attempted to learn about the organization of chromosomes by asking how many functional units can be localized within a chromomere. This was done by 1) recovery of mutants representative of every cistron in the 3A2-3C2 region; 2) the characterization of the function of each mutant type and grouping by complementation tests; 3) the determination of the genetic and cytological position of each cistron by recombination and deletion mapping. The data clearly show one functional group per chromomere. It is postulated that a chromomere is one cistron within which much of the DNA is regulatory in function.


2008 ◽  
Vol 36 (4) ◽  
pp. 567-574 ◽  
Author(s):  
V. Ramakrishnan

The determination of the high-resolution structures of ribosomal subunits in the year 2000 and of the entire ribosome a few years later are revolutionizing our understanding of the role of the ribosome in translation. In the present article, I summarize the main contributions from our laboratory to this worldwide effort. These include the determination of the structure of the 30S ribosomal subunit and its complexes with antibiotics, the role of the 30S subunit in decoding, and the high-resolution structure of the entire 70S ribosome complexed with mRNA and tRNA.


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