scholarly journals Physicochemical characteristics of the Dombrovska pit lake (Ukraine) formed in an opencast potassium salt mine and the genome response of Chironomus salinarius Kieffer (Chironomidae, Diptera) to these conditions

2020 ◽  
Vol 28 (1) ◽  
pp. 446-458
Author(s):  
Paraskeva Michailova ◽  
Ewa Szarek-Gwiazda ◽  
Andrzej Kownacki

AbstractThis study focuses on the Dombrovska pit lake, near the city of Kalush in Ukraine, which is a former potassium salt mine filled with brine and freshwater. The water level is still increasing and as a result the salinity is decreasing. We analyzed the benthic fauna communities and the genome instability by assessing the rearrangements in the polytene chromosomes of Chironomus salinarius and the physicochemical parameters of the near-bottom water (pH, conductivity, mineralization, major ions, NO3−, NH4+, metals Cd, Pb, Cu, Mn, and Fe) and sediment (pH, organic matter and metals Cd, Pb, Cu, Zn, Mn, and Fe) at four sites. The water mineralization ranged from 17.3 to 26.2 g dm−3 which are classified as mesohaline and polyhaline waters, respectively. The biodiversity of the benthic fauna was low, and the dominant species was C. salinarius. The density of C. salinarius varied spatially and changed from 637 ind./m2 at a depth of 5 m to 8167 ind./m2 at a depth of 2.5 m. The genome instability was analyzed by examining the structural and functional changes in the salivary gland chromosomes of C. salinarius. The exposure of C. salinarius damaged the chromosomes and the activities of key structures, such as the Balbiani ring and nucleolar organizer, were partially or completely suppressed.

2018 ◽  
Vol 37 (3) ◽  
pp. 456-469 ◽  
Author(s):  
Roman Żurek ◽  
Vasyl Diakiv ◽  
Ewa Szarek-Gwiazda ◽  
Joanna Kosiba ◽  
Agata Z. Wojtal
Keyword(s):  

1987 ◽  
Vol 104 (6) ◽  
pp. 1471-1483 ◽  
Author(s):  
M Hochstrasser ◽  
J W Sedat

In the preceding article we compared the general organization of polytene chromosomes in four different Drosophila melanogaster cell types. Here we describe experiments aimed at testing for a potential role of three-dimensional chromosome folding and positioning in modulating gene expression and examining specific chromosome interactions with different nuclear structures. By charting the configurations of salivary gland chromosomes as the cells undergo functional changes, it is shown that loci are not repositioned within the nucleus when the pattern of transcription changes. Heterologous loci show no evidence of specific physical interactions with one another in any of the cell types. However, a specific subset of chromosomal loci is attached to the nuclear envelope, and this subset is extremely similar in at least two tissues. In contrast, no specific interactions between any locus and the nucleolus are found, but the base of the X chromosome, containing the nucleolar organizer, is closely linked to this organelle. These results are used to evaluate models of gene regulation that involve the specific intranuclear positioning of gene sequences. Finally, data are presented on an unusual class of nuclear envelope structures, filled with large, electron-dense particles, that are usually associated with chromosomes.


2020 ◽  
Vol 14 (2) ◽  
pp. 57-68
Author(s):  
A. Haydyn ◽  
◽  
V. Dyakiv ◽  
N. Romanyuk ◽  
V. Kozlovskyy ◽  
...  

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.


2012 ◽  
Vol 31 (0) ◽  
Author(s):  
Paraskeva Vladimirova Michailova ◽  
Gabriella Sella ◽  
Ninel Petrova

2010 ◽  
Vol 56 (4) ◽  
pp. 437-444 ◽  
Author(s):  
Willie Henry ◽  
Subrata Kumar Dey ◽  
Rakesh Varma ◽  
Sachin Thapa ◽  
William S Procunier

Abstract High quality polytene chromosome maps (n=3) of a Himalayan Simuliid Simulium praelargum Datta, 1973 are presented and represent the first cytological description of a taxon found in the feuerborni group, subgenus Nevermannia. Polytene chromosomes one (I) and two (II) are metacentric, chromosome three (III) is submetacentric with the length of each chromosome occupying 37.25 %, 31.36 % and 31.34 % of the total complement length, respectively. Typical simuliid diagnostic intergeneric chromosomal markers are found within the polytene complement of this species. The nucleolar organizer (N.O.) is found at the base of the short arm of chromosome one (IS), the Ring of Balbiani (R.B.), double bubble (D.B.) and triad occur in the short arm of chromosome two (IIS), the Parabalbiani Ring (P.B.) and grey band (gb) occur in the long arm of chromosome two (IIL) and the Blister (BL) and Capsule (Ca) occur in the short arm of chromosome three (IIIS).Terminal bands at the end of IIIS are heterochromatinized and present atypically with respect to other simuliid fauna. Populations studied so far are unique among the Simuliidae in that they exhibit chromosome structural monomorphism. These high resolution polytene chromosome maps will form the basis for future cytological characterization and phylogenetic comparisons amongst members of the feuerborni group.


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


2000 ◽  
Author(s):  
A. Schuck ◽  
J. Kulenkampff ◽  
U. Lindner
Keyword(s):  

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