POLYTENE CHROMOSOMES OF GLYPTOTENDIPES GLAUCUS MG. (DIPTERA, CHIRONOMIDAE) AS TEST – OBJEKT TO STUDY TOXIC EFFECTS OF LEAD IONS

Author(s):  
N. A. Durnova ◽  
Y. V. Klimovа ◽  
M. Y. Voronin

Results of the analysis of cytogenetic effects of lead ions on polytene chromosomes of Glyptotendipes glaucus Mg are reported. The functional state of polytene chromosomes was determined via computation: chromosome compactness index (CR); coefficient of genetic activity of the nucleolar organizer (NOR) and coefficient of genetic activity of the Balbiani ring (BR). With increase of the lead nitrate solution concentration, the compactness index increases, that is, the chromosomes compactness decreases: medians of CR values (when measuring shoulder E) in the control are 6.05, for the maximum concentration studied they are 7.3. As a result of the of lead ions action, the activity of the nucleolar organizer genes decreases: medians of the NOR values decrease from 2.3 in the control to 2.0 for the highest concentrations used in the experiment. The activity of the Balbiani ring genes increases with the growing concentration of the lead nitrate solution: medians of the BR values in the control are 1.45, for the maximum studied concentration they are 1.95. The G. glaucus genome responds ambiguously to the change in the lead ions concentration in the medium: the coefficient of the nucleolar organizer’s genetic activity decreases, while the genetic activity of the Balbiani ring, on the contrary, increases.

2019 ◽  
Vol 17 (2) ◽  
pp. 55-62
Author(s):  
Yulia V. Belonogova ◽  
Natalia A. Durnova ◽  
Anna S. Sheremetyeva

Background. Experimental conditions allow to determine the structural and functional changes of polytene chromosomes under the influence of free ions of an individual metal. Materials and methods. C. plumosus (L.) and G. glaucus (Mg) larvae were placed in solutions of lead nitrate: 0.01, 0.02, 0.1 and 0.5 mg/l. Exposure 12 h. Analysis of preparations of polytene chromosomes was carried out using the Carl Zeiss PrimoStar microscope. The functional activity factor of the nucleolus organizer (NOR), the coefficient of genetic activity of the Balbiani ring (BRR) was calculated. Results. Equations of the dependence of the change in the coefficients: NOR = 5,1870,01 lnC for C. plumosus and NOR = 2,110,03 lnC for G. glaucus; BRR = 1,5040,04 lnC for C. plumosus and BRR = 2,018 + 0,03 lnC for G. glaucus. Conclusion. With an increase in the concentration of lead in both C. plumosus and G. glaucus decreases NOR, which implies a decrease in the intensity of protein biosynthesis processes. BRR decreases in C. plumosus and increases in G. glaucus. The different genome reactions of the two species indicate the existence of different mechanisms of adaptation to lead ions


1978 ◽  
Vol 26 (10) ◽  
pp. 772-781 ◽  
Author(s):  
W D Klohs ◽  
C W Goff ◽  
R J Bernacki

As the initial step toward the cytochemical localization of glycosyl-transferases in situ, biochemical determinations of these enzyme activities from onion root tips and L1210 cells were performed before and after fixation as well as in the presence of lead ions. Glycosyltransferase activity from roots fixed in buffered formaldehyde or glutaraldehyde before homogenization decreased as the concentration of the fixative or fixation time was increased. Formaldehyde fixation was less inhibitory than glutaraldehyde; 35% of the glycosyltransferase activity was retained after 30 min fixation in 2% formaldehyde while 25% of the enzyme activity remained after a similar fixation in glutaraldehyde. Substantially higher levels of L1210 cell glycosyltransferase activity were retained after a 30 min 2% formaldehyde fixation (60% sialyltransferase; 82% galactosyltransferase), but inhibition by glutaraldehyde was similar to that observed for onion root galactosyltransferase. Glycosyltransferase from formaldehyde-fixed roots was inhbited 35% by lead nitrate, but sialytransferase from formaldehyde-fixed L1210 cells was unaffected by lead ions. These findings are encouraging for further studies aimed at the development of cytochemical technique to localize glycosyltransferase in plant and animal tissues.


2019 ◽  
Vol 55 (5) ◽  
pp. 364-369
Author(s):  
Yingwu Yao ◽  
Chunjiao Huang ◽  
Haishu Dong ◽  
Feng Wei ◽  
Xin Chen

1974 ◽  
Vol 62 (1) ◽  
pp. 132-144 ◽  
Author(s):  
Wu-Nan Wen ◽  
Pedro E. León ◽  
Donald R. Hague

Ribosomal RNAs (28 + 18S and 5S) and 4S RNA extracted from the chironomid Glyptotendipes barbipes were iodinated in vitro with 125I and hybridized to the salivary gland chromosomes of G. barbipes and Drosophila melanogaster. Iodinated 18 + 28 S RNA labeled three puffed sites with associated nucleoli on chromosomes IR, IIL, and IIIL of G. barbipes and the nucleolar organizer of Drosophila. Labeled 5S RNA hybridized to three sites on chromosome IIIR, two sites on chromosome IIR and one site in a Balbiani ring on chromosome IV of Glyptotendipes. Most of the label produced by this RNA was localized seven bands away from the centromere on the right arm of chromosome III, and we consider this to be the main site complementary to 5S RNA in the chironomid. This same RNA preparation specifically labeled the 56 EF region of chromosome IIR of Drosophila which has been shown previously to be the only site labeled when hybridized with homologous 5S RNA. Hybridization of G. barbipes chromosomes with iodinated 4S RNA produced no clearly localized labeled sites over the exposure periods studied.


Zootaxa ◽  
2008 ◽  
Vol 1676 (1) ◽  
pp. 57 ◽  
Author(s):  
NEUSA HAMADA ◽  
ELENY DA SILVA PEREIRA ◽  
PETER H. ADLER

Last-instar larvae of Simulium (Psaroniocompsa) daltanhani Hamada and Adler from a stream in Central Amazonia were analyzed cytologically by mapping their polytene chromosomes. Simulium daltanhani has the nucleolar organizer in the short arm of chromosome I, heterogametic females, and an absence of autosomal polymorphisms. The chromosomes carry multiple rearrangements relative to other analyzed members of the S. quadrifidum species group in the subgenus Psaroniocompsa. One-third of the chromosomal complement is rearranged relative to the sequence of S. ulyssesi, the species with the most similar banding pattern among studied members of the S. quadrifidum group.


1963 ◽  
Vol 17 (3) ◽  
pp. 571-586 ◽  
Author(s):  
Bertalan Csillik

Cross-striated muscles of frogs and rats were fixed in 3.3 per cent lead nitrate solution. Frozen sections 30 micra thick were mounted in different media and observed by polarization microscopy. The subneural apparatus of myoneural junctions exhibits a strong birefringence in these sections. Birefringence is exerted by a highly organized lipoprotein framework (postsynaptic material) which builds up the "organites" (junctional folds) of the postsynaptic membrane. Synaptic cholinesterase is closely associated with this material. Freezing and/or formalin fixation results in a destruction of the molecular organization of the postsynaptic material, but does not influence the synaptic enzyme activity. It is hypothesized from this study that the junctional folds (postsynaptic "organites") consist of regularly arranged, sheet-like lamellar micellae in the frog and of less regular, mainly radially arranged submicroscopic units in the rat. The micellar organization as revealed by polarization analysis is in good agreement with the electron microscopic findings reported in the literature. Intramicellar protein molecules of the resting postsynaptic membrane are arranged longitudinally, lipids transversely. Supramaximal stimulation or treatment with acetylcholine + eserine results in a disorganization of proteins and a rearrangement of lipids. Denervation results in a rearrangement of lipids without any significant alterations of proteins. All these functional stresses influence only the molecular and not the micellar structure of the membrane. The function of the organized lipoprotein framework as an acetylcholine receptor is suggested.


Genome ◽  
1992 ◽  
Vol 35 (1) ◽  
pp. 64-67 ◽  
Author(s):  
P. Mavragani-Tsipidou ◽  
Z. G. Scouras ◽  
A. Natsiou-Voziki

A study of the BR1 and of the most prominent puffs during larval development and after in vitro ecdysterone treatment, as well as of the banding pattern and inverted tandem chromosomal duplications of the salivary gland chromosomes of Drosophila bicornuta, is presented in this report. These data are compared and discussed with those of D. auraria and D. serrata, two other montium species.Key words: Drosophila, Balbiani ring, duplications, ecdysterone.


1992 ◽  
Vol 117 (3) ◽  
pp. 483-491 ◽  
Author(s):  
A L Olins ◽  
D E Olins ◽  
D P Bazett-Jones

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.


2019 ◽  
Vol 50 (Special) ◽  
Author(s):  
Al-Hassoon & et al.

This study investigate the effect of concentration of lead ions (Pb2+) at 0,1, 2, 3, 4, 5, 10,20,30, 40,50 and 100 mg L-1, concentrations of the quantity of the adsorbed Pb on surface of calcium carbonate at a temperature of 298° Kelvin with all other variables remained constant, was carried out and this experiment was conducted in a single batch and using lead nitrate solution . The results showed that quantity of the adsorbed lead increased from 2.6 to 1924 mg kg-1 Calcium carbonate, and when single and two surface  Langmuir, Freundlich, Temkin, Dubinin and Polani equations were applied, they were able to describe lead adsorption on the surface of calcium carbonate at the used concentrations. The two surface Langmuir equation was  most efficient in used mathematical description of  lead adsorption, and the bonding energy (K) with the first and second surfaces were  4.02 and 1613.42 L mg-1 respectively. The adsorption capacity (Xm) values with the first and second surfaces were 0.25 and 0.89 mg    kg -1 respectively , and this clearly indicated to high capacity of the second surface (carbonate surface) to adsorb lead.


Sign in / Sign up

Export Citation Format

Share Document