Osmium tetroxide/p-phenylenediamine staining of nucleoli and balbiani rings in Chironomus salivary glands

1977 ◽  
Vol 53 (1) ◽  
pp. 43-56 ◽  
Author(s):  
Juan C. Stockert
Keyword(s):  
Salivary Glands ◽  
Osmium Tetroxide ◽  
Balbiani Rings

PERCHLORIC ACID EXTRACTION OF DEOXYRIBONUCLEIC ACID FROM THIN SECTIONS OF EPON-ARALDITE-EMBEDDED MATERIAL

1970 ◽  
Vol 18 (7) ◽  
pp. 510-514 ◽  
Author(s):  
WILLIAM H. J. DOUGLAS
Keyword(s):  
Epoxy Resin ◽  
Salivary Glands ◽  
Perchloric Acid ◽  
Ribonucleic Acid ◽  
Osmium Tetroxide ◽  
Deoxyribonucleic Acid ◽  
Polytene Chromosomes ◽  
Acid Extraction ◽  
Thin Sections ◽  
Chromosome Bands

A method is presented for the extraction of deoxyribonucleic acid from thin sections of tissue fixed in glutaraldehyde and osmium tetroxide and embedded in water-insoluble epoxy resin. Incubation of thin sections in 20% perchloric acid at 60°C for 8 hr produced electron-transparent bands in the polytene chromosomes from Drosophila salivary glands. Chromosome bands were also rendered electron-transparent when hydroxypropylmethacrylate-embedded thin sections were digested with deoxyribonuclease or extracted with perchloric acid. Nucleolar ribonucleic acid was unaffected by the perchloric acid extraction.

scholarly journals Cytogenetic comparison of chironomid midge Glyptotendipes glaucus (Meigen, 1818) (Diptera, Chironomidae) populations from Northwest Russia and Ukraine (Chernobyl zone)

2012 ◽  
Vol 10 (2) ◽  
pp. 9-16 ◽  
Author(s):  
◽  
Sergey V Zhirov
Keyword(s):  
Salivary Glands ◽  
Chromosomal Rearrangements ◽  
Radioactive Pollution ◽  
Functional Changes ◽  
Balbiani Rings ◽  
Polythene Chromosomes ◽  
Glyptotendipes Glaucus ◽  
Chernobyl Zone

Functional characters of polythene chromosomes and chromosomal rearrangements in salivary glands of 177 larvae of Glyptotendipes glaucus (Diptera, Chironomidae) from reservoirs of Russia and Ukraine (Chernobyl) have been analysed. Similarity of the populations studied based on a pool of chromosomal reorganizations has been established. The general types of inversions in chromosomal arms A, B, D and E have been detected. Influence of radioactive pollution (Chernobyl) on functional changes of a nucleus, Balbiani rings, puffs, morphology of disks and interdisks is revealed. 

scholarly journals Aquatic silk proteins in Chironomus: A review

2018 ◽  
Author(s):  
Leena J. Thorat ◽  
Bimalendu B. Nath
Keyword(s):  
Environmental Factors ◽  
Salivary Glands ◽  
Significant Role ◽  
Balbiani Ring ◽  
Silk Proteins ◽  
Pilot Studies ◽  
Chironomid Midges ◽  
Balbiani Rings ◽  
Literature Database

Silk proteins secreted by salivary glands in the dipteran insect, Chironomus play a significant role as proteinaceous adhesives for construction of underwater housing nests by larvae. To date, only three Chironomus species, C. tentans Fabricius, C. pallidivittatus Malloch and C. riparius Meigen have been explored for characterization of their aquatic silk protein. Genes coding for silk proteins are located on specific chromosomal ‘puffs’ called Balbiani rings as well as non-Balbiani ring regions.  Expression of these genes is closely regulated by developmental and hormonal alterations and environmental factors. Furthermore, pilot studies have postulated that silk proteins probably occur in diverse size classes grouped into large (~1000 kDa), intermediate (100-200 kDa) and small (≤100 kDa). Barring few preliminary reports that date back to the 1990s, the physical and bioproperties of silk from chironomid midges remain largely unknown, leading to paucity of updated information. This review was therefore aimed to compile existing literature database and to highlight the wide possibilities for commercialization of midge larval silk as a novel biopolymer.

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 Large-sized polysomes in Chironomus tentans salivary glands and their relation to Balbiani ring 75S RNA.

1977 ◽  
Vol 73 (1) ◽  
pp. 149-160 ◽  
Author(s):  
B Daneholt ◽  
K Anderson ◽  
M Fagerlind
Keyword(s):  
Salivary Glands ◽  
Messenger Rna ◽  
High Yield ◽  
Chironomus Tentans ◽  
Balbiani Ring ◽  
Rna Molecules ◽  
Large Size ◽  
Present Information ◽  
Balbiani Rings ◽  
Available Information

Polysomes from the salivary glands of Chironomus tentans were investigated to determine whether Balbiani ring 75S RNA is incorporated into polysomal structures, and thus probably acts as messenger RNA. A new extraction technique for obtaining ribonucleoproteins was applied that gives a high yield of polysomes with only moderate degradation of the cytoplasmic, high molecular weight RNA. The polysomes sedimented in a broad region (200-2,000S) with a peak value of about 700S, which suggested that they were partly of very large sizes. This was confirmed by visualization of the polysomes in the electron microscope: 400S polysomes contained mainly 11-16 ribosomes, and 1,500S polysomes about 60 ribosomes per polysome. However, polysomes containing 100 or more ribosomes were also observed. It was further established that most of the cytoplasmic 75S RNA was located in polysomes, preferentially in the most rapidly sedimenting ones. From the available information on Balbiani ring RNA in cytoplasm and the present demonstration of 75S RNA molecules in polysomes, it was concluded that at least some Balbiani ring RNA, generated as 75S RNA within the Balbiani rings, eventually enters polysomes without being measurably changed in size. The present information on the potential amino acid coding sequences in 75S RNA is discussed in relation to the large size of the polysomes observed.

Cellular Contacts Within the Interhemal Membrane of the Rat Placenta at Term

1974 ◽  
Vol 32 ◽  
pp. 146-147
Author(s):  
William P. Jollie
Keyword(s):  
Osmium Tetroxide ◽  
Uranyl Acetate ◽  
Capillary Endothelium ◽  
En Bloc ◽  
Aldehyde Fixation ◽  
Chorioallantoic Placenta

By routine EM preparative techniques, the tissues which, collectively, separate maternal and fetal bloods in the fully formed chorioallantoic placenta of the rat have been shown to consist of three chorionic layers, or trophoblast, and a layer of allantoic capillary endothelium [Fig. 1]. Relationships between these layers are best demonstrated by special techniques, viz., cacodylate-buffered aldehyde fixation, collidine-buffered osmium tetroxide postfixation, and en bloc staining with uranyl acetate. By using this method on placentas at term, the cells of the outermost chorionic layer (Trophoblast 1) appear to be attached to each other by means of maculae adherentes which sometimes occur in clusters [Fig. 2].

Ultrastructural Analysis of the Salivary Glands of Gromphadorhina Portentosa (Schaum)

1977 ◽  
Vol 35 ◽  
pp. 638-639
Author(s):  
P.J. Dailey
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Salivary Glands ◽  
Secretory Vesicles ◽  
The Past ◽  
Transmission Electron ◽  
Means Of Transmission ◽  
Gromphadorhina Portentosa ◽  
Scanning Electron ◽  
Topographical Relief

The structure of insect salivary glands has been extensively investigated during the past decade; however, none have attempted scanning electron microscopy (SEM) in ultrastructural examinations of these secretory organs. This study correlates fine structure by means of SEM cryofractography with that of thin-sectioned epoxy embedded material observed by means of transmission electron microscopy (TEM).Salivary glands of Gromphadorhina portentosa were excised and immediately submerged in cold (4°C) paraformaldehyde-glutaraldehyde fixative1 for 2 hr, washed and post-fixed in 1 per cent 0s04 in phosphosphate buffer (4°C for 2 hr). After ethanolic dehydration half of the samples were embedded in Epon 812 for TEM and half cryofractured and subsequently critical point dried for SEM. Dried specimens were mounted on aluminum stubs and coated with approximately 150 Å of gold in a cold sputtering apparatus.Figure 1 shows a cryofractured plane through a salivary acinus revealing topographical relief of secretory vesicles.

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