Balbiani Rings

2001 ◽  
pp. 190-191
Author(s):  
J.C.J. Eeken
Keyword(s):  
Balbiani Rings

Heat-shock induced puffing changes in Balbiani rings

Chromosoma ◽  
1971 ◽  
Vol 32 (2) ◽  
Author(s):  
Hiroshi Yamamoto
Keyword(s):  
Heat Shock ◽  
Balbiani Rings

FINE STRUCTURE OF NUCLEOLI AND RNA-CONTAINING CHROMOSOME REGIONS OF SALIVARY GLAND CHROMOSOMES OF CHIRONOMIDS AND THEIR INTERRELATIONSHIP

1964 ◽  
Vol 42 (6) ◽  
pp. 1147-1155 ◽  
Author(s):  
V. I. Kalnins ◽  
H. F. Stich ◽  
S. A. Bencosme
Keyword(s):  
Fine Structure ◽  
Salivary Gland ◽  
Electron Microscope ◽  
Light Microscopy ◽  
Messenger Rna ◽  
Balbiani Ring ◽  
Electron Microscopic ◽  
Chironomid Species ◽  
Balbiani Rings ◽  
Chromosome Regions

Electron microscope studies of salivary gland nuclei of four chironomid species have shown that the RNA-containing chromosome regions and associated structures, which by light microscopy exhibit a great variety of structures such as bands, granules, micronucleoli, nucleoli, puffs, and Balbiani rings, consist of only few basic units: pars amorpha, nucleolonema, and Balbiani ring granules. The fine structure of the nucleoli and spherical micronucleoli located at various chromosome regions appears to be identical, consisting of pars amorpha, which contains fibers of varying diameters, and strands of nucleolonema composed of fibers and ribosome-like granules. The arrangement of pars amorpha and nucleolonema of nucleoli and spherical micronucleoli follows a consistent pattern. Chromosome fibers are closely associated with pars amorpha, whereas strands of nucleolonema border only the surfaces of pars amorpha. Balbiani ring granules, which have a diameter of 300 Å to 500 Å and are characterized by a particular structure, accumulate in Balbiani rings, in many chromosome regions, and in nuclear sap. In the Balbiani ring these granules seem to be attached to 100 Å chromosome fibers. They are absent in nucleoli and micronucleoli. The possible correlation between our electron microscopic observations and the present-day concept of ribosomal and messenger RNA production is discussed.

scholarly journals Balbiani ring hnRNP substructure visualized by selective staining and electron spectroscopic imaging.

1992 ◽  
Vol 117 (3) ◽  
pp. 483-491 ◽  
Author(s):  
A L Olins ◽  
D E Olins ◽  
D P Bazett-Jones
Keyword(s):  
Nucleic Acid ◽  
Polytene Chromosomes ◽  
Particle Diameter ◽  
Balbiani Ring ◽  
Electron Spectroscopic Imaging ◽  
Selective Staining ◽  
Elemental Imaging ◽  
Mature Transcript ◽  
Balbiani Rings ◽  
Relationship Of

The Balbiani Rings (BR) in the polytene chromosomes of Chironomus salivary glands are intense sites of transcription. The nascent RNPs fold during transcription into 40-50-nm granules, containing in the mature transcript approximately 37-kb RNA. Using a new nucleic acid specific stain, osmium ammine B on Lowicryl sections, in combination with electron energy filtered imaging of sections containing BR granules, we demonstrate a RNA-rich particulate substructure (10-nm particle diameter; 10-12 particles per BR granule). Elemental imaging supports that these particles are enriched in phosphorus. The possible relationship of these RNA-rich particles to ribonucleosomes is discussed, as well as models for their arrangement in the mature BR granules.

Effect of galactose treatment in the puffing pattern of Chironomus thummi Balbiani rings

Chromosoma ◽  
1978 ◽  
Vol 69 (1) ◽  
pp. 93-100 ◽  
Author(s):  
M. C. Santa-Cruz ◽  
A. Villanueva ◽  
J. L. D�ez
Keyword(s):  
Balbiani Rings ◽  
Chironomus Thummi

Balbiani rings and puffs of the polytene chromosomes of Drosophila auraria

Chromosoma ◽  
1984 ◽  
Vol 89 (2) ◽  
pp. 96-106 ◽  
Author(s):  
Zacharias G. Scouras ◽  
Costas D. Kastritsis
Keyword(s):  
Polytene Chromosomes ◽  
Balbiani Rings

Cytotaxonomic differentiation of the Afrotropical Drosophila montium subgroup: D. diplacantha and D. seguyi. The major role of reverse tandem duplications

Genome ◽  
1994 ◽  
Vol 37 (6) ◽  
pp. 935-944 ◽  
Author(s):  
P. Mavragani-Tsipidou ◽  
A. Zambetaki ◽  
K. Kleanthous ◽  
E. Pangou ◽  
Z. G. Scouras
Keyword(s):  
Polytene Chromosomes ◽  
Balbiani Ring ◽  
Developmental Profile ◽  
Intraspecific Polymorphism ◽  
Balbiani Rings ◽  
Chromosome Maps ◽  
Temporal And Spatial ◽  
Montium Subgroup ◽  
Tandem Duplications

Aiming to establish phylogenetic relationships among species of the montium subgroup, detailed polytene chromosome maps are given showing intraspecific polymorphism and ecdysone induced larval puffing pattern profiles of two Afrotropical members of this subgroup, Drosophila diplacantha and D. seguyi. Both species exhibit two unique characteristics that define the montium subgroup, namely, a large number of reverse tandem duplications and a progressive darkening of anterior spiracles of the late third instar larvae, which is accompanied by a definite temporal and spatial puffing pattern of the salivary gland chromosomes. In contrast with the well-formed Balbiani ring 1 (BR1) observed in Oriental and Indian montium species, BR1 exhibits a different developmental profile in D. diplacantha, while it is obscured in D. seguyi. Although phyletic comparisons of five species from five different complexes within the subgroup show some conservation in banding and puffing pattern homologies, an analysis to assign map sections by sequential rearrangements remains unresolved at this time. The evolution of the subgroup is discussed in relation with the sharing of reverse tandem duplications, especially those including the montium BRs.Key words: Drosophila montium, polytene chromosomes, Balbiani rings, puffs, duplications, inversions.

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