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

Temperature-induced Balbiani rings in Chironomus thummi

Chromosoma ◽  
1981 ◽  
Vol 83 (3) ◽  
pp. 341-352 ◽  
Author(s):  
G. Morcillo ◽  
M. C. Santa-Cruz ◽  
J. L. D�ez
Keyword(s):  
Balbiani Rings ◽  
Chironomus Thummi

The transcripts of Balbiani rings from Chironomus thummi

Chromosoma ◽  
1976 ◽  
Vol 57 (3) ◽  
pp. 271-283 ◽  
Author(s):  
Edgar Serfling
Keyword(s):  
Balbiani Rings ◽  
Chironomus Thummi

Selective stimulation of puffing activity in vitro with a juvenile hormone analogue by polytene chromosomes in the salivary glands of Chironomus thummi (Diptera)

1989 ◽  
Vol 67 (10) ◽  
pp. 2528-2532
Author(s):  
X. Vafopoulou ◽  
C. G. H. Steel ◽  
H. Laufer
Keyword(s):  
Juvenile Hormone ◽  
Salivary Glands ◽  
Polytene Chromosomes ◽  
Hormone Analogue ◽  
Juvenile Hormone Analogue ◽  
Balbiani Rings ◽  
Chironomus Thummi ◽  
Stimulation Of

Salivary glands of Chironomus thummi prepupae were treated in vitro with various concentrations of the juvenile hormone analogue (JHA) methoprene and the puffing activities of Balbiani rings (BR) b and c were scored in cytological preparations of polytene chromosomes. In control cultures, both BRb and BRc regress rapidly. JHA treatment in vitro prevented regression at both these sites. In addition, BRb was found to expand within 60 min to a size two to three times larger than in control contralateral glands. The most effective concentration for stimulation of BRb and BRc in vitro was 10−7 M. In vivo treatment of prepupae with 10−7 M JHA also induced puffing activity in BRb and BRc to a degree similar to that observed following in vitro treatment. It is concluded that BRb, and perhaps also BRc, are juvenile hormone (JH) inducible chromosomal sites in Chironomus thummi salivary glands. This is the first report of chromosomal sites that are stimulated by JH in vitro in the absence of exogenous ecdysteroids. These findings support the view that JH may act at the gene level at separate loci from ecdysone.

scholarly journals RNA TRANSPORT FROM NUCLEUS TO CYTOPLASM IN CHIRONOMUS SALIVARY GLANDS

1966 ◽  
Vol 31 (1) ◽  
pp. 55-77 ◽  
Author(s):  
Barbara J. Stevens ◽  
Hewson Swift
Keyword(s):  
Nuclear Envelope ◽  
Messenger Rna ◽  
Rna Transport ◽  
Central Channel ◽  
Balbiani Ring ◽  
Apparent Effect ◽  
Nuclear Pores ◽  
Balbiani Rings ◽  
Rna Puffs ◽  
Chironomus Thummi

The fine structure and cytochemistry of the extremely large RNA puffs, or Balbiani rings, in salivary gland nuclei of midge, Chironomus thummi, larvae have been investigated. The Balbiani rings are composed of a diffuse mass of electron-opaque 400 to 500 A granules, short threads about 180 to 220 A in diameter and associated fine chromatin fibrils. These components appear to be organized into brushlike elements which form the ring. Electron microscope cytochemistry has shown that the granules and short threads contain RNA. After ribonuclease digestion, only 50 to 100 A chromatin fibrils were apparent in the Balbiani ring, and the granules were no longer demonstrable. Deoxyribonuclease digestion had no apparent effect on these structures. Observations indicate that the granules are formed from the short threads and released into the nucleoplasm in which they are evenly distributed. At the nuclear envelope, many granules have been observed partially or completely within the nuclear pores. These granules become elongated and are shown to penetrate the center of the pore in a rodlike form, about 200 A in diameter. The Balbiani ring granules are not normally visible within the cytoplasm adjacent to the nuclear envelope, but have been rarely found in this region. It is suggested that the granules represent the product of the Balbiani ring, possibly a messenger RNA bound to protein, and that they regularly pass into the cytoplasm through a narrow central channel in the pores of the nuclear envelope.

Non-reciprocal gonadal dysgenesis in hybrids of the chironomid midge Chironomus thummi

Chromosoma ◽  
1987 ◽  
Vol 96 (1) ◽  
pp. 50-54 ◽  
Author(s):  
K. H�gele ◽  
B. Oschmann
Keyword(s):  
Gonadal Dysgenesis ◽  
Chironomus Thummi

MEC: A transposable element from Chironomus thummi (Diptera)

1991 ◽  
Vol 229 (1) ◽  
pp. 152-154 ◽  
Author(s):  
A. G. Blinov ◽  
Y. V. Sobanov ◽  
E. K. Gaidamakova ◽  
S. S. Bogachev ◽  
N. N. Kolesnikov ◽  
...  
Keyword(s):  
Transposable Element ◽  
Chironomus Thummi
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