scholarly journals Differential distribution of RNA polymerase B and nonhistone chromosomal proteins in polytene chromosomes of Drosophila melanogaster.

1983 ◽  
Vol 2 (3) ◽  
pp. 395-402 ◽  
Author(s):  
R. Kabisch ◽  
E.K. Bautz
Keyword(s):  
Drosophila Melanogaster ◽  
Rna Polymerase ◽  
Polytene Chromosomes ◽  
Differential Distribution ◽  
Chromosomal Proteins

scholarly journals A cytological approach to the ordering of events in gene activation using the Sgs-4 locus of Drosophila melanogaster.

1984 ◽  
Vol 99 (1) ◽  
pp. 233-238 ◽  
Author(s):  
E K Steiner ◽  
J C Eissenberg ◽  
S C Elgin
Keyword(s):  
Rna Polymerase ◽  
Rna Polymerase Ii ◽  
Topoisomerase I ◽  
Gene Activation ◽  
Polytene Chromosomes ◽  
Null Alleles ◽  
Major Salivary Gland ◽  
Wild Type ◽  
Fluorescent Band ◽  
Chromosomal Proteins

The polytene chromosomes of Drosophila strains that differ in the synthesis of the major salivary gland glue protein sgs-4 were examined by indirect immunofluorescence using antisera to several nonhistone chromosomal proteins. The Oregon-R X chromosome, which produces sgs-4 messenger RNA, showed a strong fluorescent band at locus 3C11-12 when stained with anti-RNA polymerase II, whereas the null mutant Berkeley 1 failed to exhibit fluorescence at that locus. The presence of another antigen (Band 2), normally associated with developmentally active loci, was clearly evident at locus 3C11-12 of both transcriptionally competent and null strains, indicating that the association of Band 2 antigen with the chromatin is an event independent of RNA polymerase II binding. Antibodies directed against Drosophila topoisomerase I stained 3C11-12 in the Sgs-4+ (wild-type) strain brightly, but gave significantly less staining in the null strain. This indicates that the high concentrations of topoisomerase I seen at active loci are closely associated with the transcriptional event. In some of these analyses, we have made use of flies heterozygous for the wild-type and null alleles in order to make internally controlled comparisons. The results suggest that this type of analysis will enable conclusions to be drawn concerning the interdependence and order of action of chromosomal proteins involved in developmental gene activation.

scholarly journals dCHD3, a Novel ATP-Dependent Chromatin Remodeler Associated with Sites of Active Transcription

2008 ◽  
Vol 28 (8) ◽  
pp. 2745-2757 ◽  
Author(s):  
Magdalena Murawska ◽  
Natascha Kunert ◽  
Joke van Vugt ◽  
Gernot Längst ◽  
Elisabeth Kremmer ◽  
...  
Keyword(s):  
Drosophila Melanogaster ◽  
Rna Polymerase ◽  
Rna Polymerase Ii ◽  
Nuclear Protein ◽  
Polytene Chromosomes ◽  
Dependent Manner ◽  
Chromatin Remodelers ◽  
Active Transcription ◽  
Nucleosome Binding

ABSTRACT ATP-dependent chromatin remodelers of the CHD family play important roles during differentiation and development. Three CHD proteins, dMi-2, dChd1, and Kismet, have been described for Drosophila melanogaster. Here, we study dCHD3, a novel member of the CHD family. dCHD3 is related in sequence to dMi-2 but lacks several domains implicated in dMi-2 function. We demonstrate that dCHD3 is a nuclear protein and that expression is tightly regulated during fly development. Recombinant dCHD3 remodels mono- and polynucleosomes in an ATP-dependent manner in vitro. Its chromodomains are critical for nucleosome binding and remodeling. Unlike dMi-2, dCHD3 exists as a monomer. Nevertheless, both proteins colocalize with RNA polymerase II to actively transcribed regions on polytene chromosomes, suggesting that both remodelers participate in the process of transcription.

scholarly journals Chromosomal Distribution of Transposable Elements in Drosophila melanogaster Test of the Ectopic Recombination Model for Maintenance of Insertion Site Number

Genetics ◽  
1996 ◽  
Vol 144 (1) ◽  
pp. 197-204
Author(s):  
Christine Hoogland ◽  
Christian Biémont
Keyword(s):  
Drosophila Melanogaster ◽  
Transposable Elements ◽  
Dna Content ◽  
Recombination Rate ◽  
Alternative Hypothesis ◽  
Insertion Site ◽  
Polytene Chromosomes ◽  
Negative Relationship ◽  
Site Occupancy ◽  
Site Number

Abstract Data of insertion site localization and site occupancy frequency of P, hobo, I, copia, mdg1, mdg3, 412, 297, and roo transposable elements (TEs) on the polytene chromosomes of Drosophila melanogaster were extracted from the literature. We show that TE insertion site number per chromosomal division was significantly correlated with the amount of DNA. The insertion site number weighted by DNA content was not correlated with recombination rate for all TEs except hobo, for which a positive correlation was detected. No global tendency emerged in the relationship between TE site occupancy frequency, weighted by DNA content, and recombination rate; a strong negative correlation was, however, found for the 3L arm. A possible dominant deleterious effect of chromosomal rearrangements due to recombination between TE insertions is thus not the main factor explaining the dynamics of TEs, since this hypothesis implies a negative relationship between recombination rate and both TE insertion site number and site occupancy frequency. The alternative hypothesis of selection against deleterious effects of insertional mutations is discussed.

Microdissection and cloning of DNA from a specific region of Drosophila melanogaster polytene chromosomes

Chromosoma ◽  
1981 ◽  
Vol 82 (2) ◽  
pp. 205-216 ◽  
Author(s):  
F. Scalenghe ◽  
E. Turco ◽  
J. E. Edström ◽  
V. Pirrotta ◽  
M. Melli
Keyword(s):  
Drosophila Melanogaster ◽  
Polytene Chromosomes ◽  
Specific Region

Ultrastructure of polytene chromosomes of Drosophila isolated by microdissection

1980 ◽  
Vol 45 (1) ◽  
pp. 15-30
Author(s):  
M.R. Mott ◽  
E.J. Burnett ◽  
R.J. Hill
Keyword(s):  
Electron Microscope ◽  
Polytene Chromosomes ◽  
Ultrastructural Level ◽  
Chromosomal Proteins ◽  
Linear Arrays ◽  
Ribonucleoprotein Particles ◽  
Acid Protein

Drosophila polytene chromosomes prepared by a new micromanipulative procedure, which avoids acid squashing, have been examined at the ultrastructural level in the electron microscope. Puffs at 2B, 68C, 74EF, 75B and 85EF, have been examined in some detail, along with the chromocentre and various interbands. The ultrastructure of these chromosomes, which have never been exposed to acid protein denaturants, compares favourably with that of classical acid-fixed specimens. Ribonucleoprotein particles in puffs are seen to be organized in linear arrays and evidence is adduced for looped transcription units. Particles with characteristic sizes and morphologies are observed near the chromocentre, in puffs and in interbands. In interbands RNP particles and ‘superbead’-like chromatin particles may be distinguished. Drosophila polytene chromosomes isolated by micro-manipulation should prove useful for the localization of native chromosomal proteins at an ultrastructural level.

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