scholarly journals MASS PREPARATION OF NUCLEI FROM THE LARVAL SALIVARY GLANDS OF DROSOPHILA HYDEI

1968 ◽  
Vol 38 (2) ◽  
pp. 369-376 ◽  
Author(s):  
James B. Boyd ◽  
Hans D. Berendes ◽  
Hudson Boyd
Keyword(s):  
Salivary Glands ◽  
Polytene Chromosomes ◽  
Normal Appearance ◽  
Drosophila Hydei ◽  
Rna And Dna ◽  
Third Instar Larvae

A method has been developed for isolating gram quantities of salivary glands from late third instar larvae of Drosophila hydei. The isolated glands have a normal appearance and incorporate RNA and DNA precursors normally. Nuclei can be isolated from these glands in 90% yield with the use of detergents. These nuclei contain morphologically normal giant polytene chromosomes.

Activation of potential initiation sites of DNA replication and induction of new initiation within the same cycle by puromycin in Drosophila polytene chromosomes

1984 ◽  
Vol 65 (1) ◽  
pp. 95-109
Author(s):  
A.S. Mukherjee ◽  
C. Chatterjee
Keyword(s):  
Dna Replication ◽  
Salivary Glands ◽  
Polytene Chromosomes ◽  
Cell System ◽  
Replication Cycle ◽  
Physiological Conditions ◽  
Protein Factor ◽  
Drosophila Hydei ◽  
Alpha Amanitin ◽  
Potential Initiation

DNA replication in the polytene chromosomes of larval salivary glands of Drosophila hydei has been examined under normal physiological conditions, with or without puromycin, by an autoradiographic procedure using [3H]thymidine. It has been demonstrated that puromycin induces new labelling patterns that can be identified as initiation patterns. Such initiation patterns were found to have been induced during both the initial (interband labelling patterns) and the terminal (discontinuous) phases. Both induced patterns are sensitive to alpha-amanitin. These findings lead us to suggest that (a) the puff-interband-labelled patterns are indeed the initial patterns, and (b) the induction of new initiation, which is normally known to be prevented until the completion of the cycle, can be brought about by puromycin. The results also suggest the probable existence of a pool of protein factor(s) for the initiation of a replication cycle already present in the cell system.

scholarly journals Impacts of dietary exposure to sodium or potassium salts of nitrate and nitrite on the development of Drosophila melanogaster

2017 ◽  
Vol 10 (2) ◽  
pp. 70-78 ◽  
Author(s):  
Ashim Kumar Basak ◽  
Tridip Chatterjee ◽  
Swapan Kumar Ghosh ◽  
Amit Chakravarty
Keyword(s):  
Young Adults ◽  
Food Additives ◽  
Polytene Chromosomes ◽  
Model Organism ◽  
Developmental Outcomes ◽  
Dietary Exposure ◽  
Potassium Nitrate ◽  
Toxicological Studies ◽  
Nitrate And Nitrite ◽  
Third Instar Larvae

AbstractThe effects of four food additives, namely sodium nitrite (NaNO2), sodium nitrate (NaNO3), potassium nitrite (KNO2), and potassium nitrate (KNO3), on animal development were evaluated by using Drosophila melanogster, a model organism. Adult male and female flies were allowed to breed in culture medium, each containing one of 4 concentrations,i.e.10, 20, 30 or 40 mM of the above mentioned salts. The concentration of 40 mM, NaNO2and KNO2 completely arrested the development of the flies. Of the different concentrations of the four salts tested, exposure of flies to 30 mM NaNO2exhibited only significant delays in the initial appearances of third instar larvae, pupae and young adults, along with huge reduction in the number of pupae and young adults compared to controls. Rearrangements like inversions, deletion looping, regional shrinking, as well as highly enlarged puffing,etc.were also observed in the polytene chromosomes of the third instar larvae exposed to 30 mM NaNO2. Developmental outcomes of the flies exposed to varying concentrations of NaNO3and KNO3 did not differ significantly from the controls. Owing to the extensive genetic homology between Drosophila and human and the successful uses of this fly as models in developmental and toxicological studies, we speculate that the experimental results exhibited by this organism in our study strongly advocate for abstaining from the dietary use of NaNO2and KNO2 during human pregnancies to avoid possible negative developmental outcomes.

A comparison of polytene chromosomes in salivary glands and orbital bristle trichogen cells in Ceratitis capitata

Genome ◽  
1991 ◽  
Vol 34 (2) ◽  
pp. 215-219 ◽  
Author(s):  
A. Zacharopoulou ◽  
K. Bourtzis ◽  
Ph. Kerremans
Keyword(s):  
Salivary Gland ◽  
Salivary Glands ◽  
Banding Pattern ◽  
Ceratitis Capitata ◽  
Polytene Chromosomes ◽  
Biological Significance ◽  
Fruit Fly ◽  
Banding Patterns ◽  
Homologous Chromosomes ◽  
Different Tissues

The banding patterns of polytene chromosomes in different tissues of the Mediterranean fruit fly, Ceratitis capitata, vary to such an extent that homologous chromosomes cannot be recognised. However, analyses of autosomal breakpoints in several translocation strains allowed chromosomes from the two tissues to be aligned despite their difference in banding pattern. These results were discussed, considering the different hypotheses of the origin and biological significance of polytene chromosome bands.Key words: polytene chromosomes, salivary gland chromosomes, orbital bristle trichogen cell chromosomes, Ceratitis capitata.

scholarly journals Microwave Processing of Drosophila Tissues for Electron Microscopy

2004 ◽  
Vol 12 (6) ◽  
pp. 42-42 ◽  
Author(s):  
JoAnn Buchanan
Keyword(s):  
Electron Microscopy ◽  
Salivary Glands ◽  
Polytene Chromosomes ◽  
Microwave Processing ◽  
The Body ◽  
Cold Spot ◽  
Large Size ◽  
Body Tissues ◽  
Microwave Effect ◽  
Excellent Preservation

Insect tissue is often difficult to prepare for electron microscopy because of the impenetrable barrier surrounding the body tissues. Drosophila salivary glands have been used for numerous studies because of the large size of the cells and their large polytene chromosomes. Early TEM studies of salivary glands used a protocol that took several days. We were able to achieve excellent preservation and good ultrastructure in Drosophila salivary glands and imaginal discs from Stage L3 larvae using microwave processing in a protocol requiring less than 2 hours.We used a Pelco Laboratory microwave (model #3451) equipped with a Cold Spot, Steadytemp chiller/recirculator run at 15° C, and vacuum chamber (Ted Pella, Mountain Lakes, CA). The heads and attached salivary glands were removed from the animals and placed in PBS. The tissue was transferred to Pelco prep-eze specimen holders (#36157) for ease of handling. Our goal was to use the microwave effect, not the heating effect, to prepare the tissue.

scholarly journals THE EFFECT OF CHANGES IN THE RESPIRATORY METABOLISM UPON GENOME ACTIVITY

1972 ◽  
Vol 55 (2) ◽  
pp. 257-265 ◽  
Author(s):  
Hans J. Leenders ◽  
Pieter J. A. Beckers
Keyword(s):  
Enzyme Activity ◽  
Salivary Glands ◽  
Actinomycin D ◽  
Maximum Size ◽  
Respiratory Metabolism ◽  
Maximum Increase ◽  
Drosophila Hydei ◽  
Nicotinamide Adenine Dinucleotide Dehydrogenase ◽  
Genome Activity

The in vitro regression of experimentally induced chromosome puffs was investigated in explanted salivary gland chromosomes of Drosophila hydei. It was observed that the regression of the puffs 2-32A, 2-36A, 2-48C, and 4-81B is accelerated if substrates for the respiratory metabolism are supplied to the cells. A similar effect can be produced by addition of KCN or oligomycin to medium in which intact salivary glands are incubated. The acceleration of puff regression by these substances occurs not only if the puff-inducing stimulus is removed but as well under conditions in which the stimulus is maintained. Regression of the puffs 2-32A, 2-36A, and 4-81B is inhibited if cycloheximide is present in the incubation medium. Chloramphenicol has no effect on puff regression. Measurements on nicotinamide adenine dinucleotide-dehydrogenase activity in homogenates of salivary glands revealed an increase in enzyme activity of 41 %. Maximum increase is attained at 30 min after the induced puffs have reached their maximum size. The increase in enzyme activity does not occur if the glands are kept in a medium containing either actinomycin D or cycloheximide. Chloramphenicol does not inhibit the increase in enzyme activity. The possible relationship between puff activity and its control as a result of changes in the respiratory metabolism is discussed.

scholarly journals Puffing activity in Drosophila melanogaster Meig. political chromosomes after exposure to microwave radiation

2018 ◽  
Vol 23 ◽  
pp. 393-398
Author(s):  
M. N. Sheyka ◽  
V. Yu. Strashnyuk
Keyword(s):  
Drosophila Melanogaster ◽  
Salivary Glands ◽  
Power Density ◽  
Microwave Radiation ◽  
X Chromosome ◽  
Polytene Chromosomes ◽  
Early Embryogenesis ◽  
Wild Type ◽  
Ocular Micrometer ◽  
Outbred Strain

Aim. The aim of the work was to study the effect of microwave radiation of varying intensity on the polytene chromosomes puffing activity in larvae salivary glands of Drosophila melanogaster. Methods. The wild type outbred strain Oregon-R was used as the material. Microwave radiation with a frequency of 36.64 GHz and a power density of 0.1 and 1 W / m2 was used. Exposure to microwaves was applied in early embryogenesis after 3-hour oviposition. Exposure time was 30 sec. The puff sizes were studied on the squashed preparations of larvae salivary glands stained with acetoorcein. Dimensions of four puffs were investigated^ 2B5-6 (X chromosome); 62E, 71CE and 72CD (chromosome 3L). The measurements were carried out using an ocular-micrometer. Results. There were no significant changes in the size of the puffs in any of the four loci studied, regardless of the applied power density. Conclusions. Microwave radiation in early embryogenesis at a frequency of 36.64 GHz, a power density of 0.1 and 1 W/m2, and an exposure of 30 sec does not have a significant effect on the puff sizes in the Drosophila polytene chromosomes. Keywords: Drosophila melanogaster Meig., giant chromosomes, puff sizes, non-ionizing radiation.

scholarly journals PRODUCTION AND RELEASE OF A LOCUS-SPECIFIC RIBONUCLEOPROTEIN PRODUCT IN POLYTENE NUCLEI OF DROSOPHILA HYDEI

1973 ◽  
Vol 59 (3) ◽  
pp. 661-668 ◽  
Author(s):  
J. Derksen ◽  
H. D. Berendes ◽  
E. Willart
Keyword(s):  
Salivary Gland ◽  
Nuclear Membrane ◽  
Alkaline Hydrolysis ◽  
Chromosome Region ◽  
Polytene Chromosomes ◽  
Central Core ◽  
Ribonucleoprotein Complex ◽  
Drosophila Hydei ◽  
Rnase Digestion ◽  
Polytene Nuclei

A specific, 0.1–0.3-µm large ribonucleoprotein complex consisting of a central core with stalklike extensions on top of which 280–320-Å ribonucleoprotein particles are situated is found in an experimentally activated chromosome region, 2–48C, of the polytene chromosomes of Drosophila hydei. Alkaline hydrolysis, RNAse digestion, and uranyl-EDTA-lead staining indicated the ribonucleoprotein character of the 280–320-Å particles, whereas the central core seems to be devoid of RNA. The characteristic complexes are present in the nucleoplasm and at the nuclear membrane, but absent from the cytoplasm. It is suggested that the large RNP complexes are the specific products of the puff at 2–48C. Complexes similar to the ones described have not been observed in any other region of the polytene salivary gland chromosomes of this species.

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