25 results on '"Julia Ilkova"'
Search Results
2. External Morphology of Larvae of Belgica antarctica Jacobs, 1900 (Diptera, Chironomidae) Obtained from Two Locations in Maritime Antarctica
- Author
-
Paraskeva Michailova, Julia Ilkova, Pavlo A. Kovalenko, Volodymyr A. Gorobchyshyn, Iryna A. Kozeretska, and Peter Convey
- Subjects
antennae ,mouthparts ,clypeus ,pecten epipharyngis ,posterior parapods ,Science - Abstract
The external morphology of the fourth-instar larva of the Antarctic endemic chironomid midge Belgica antarctica is described. Larvae were collected from Jougla Point (Wiencke Island) and an un-named island close to Enterprise Island, off the coast of the western Antarctic Peninsula. Light microscopy was used to examine and document photographically the structures of the mouthparts (mandible, mentum, premandible, labrum), antennae, pecten epipharyngis, clypeus, frontal apotome and posterior parapods. Measurements of the mouthparts are presented. The data obtained are compared with that available in the literature. A number of differences were identified relating to the size of the larvae, the number of teeth on the mandibles, the number of antennal segments and the length of the antennal blade. Malformations of the mandible and mentum are reported for the first time in this species. Features of larvae of taxonomic value that can be used to determine the species in larval stages are presented. These are of utility in using the larvae to reveal relationships with other species. Larvae are also important in ecological and genotoxicological studies, which require accurate species level identification.
- Published
- 2021
- Full Text
- View/download PDF
3. Genome instability in Chironomus annularius sensu Strenzke (Diptera, Chironomidae): A biomarker for assessment of the heavy metal contaminants in Poland
- Author
-
Paraskeva Michailova, Julia Ilkova, Ewa Szarek-Gwiazda, Andrzej Kownacki, and Dariusz Ciszewski
- Subjects
Chironomus annularius ,genotoxicity ,chromosome aberrations ,biomarkers ,heavy metals. ,Geography. Anthropology. Recreation ,Physical geography ,GB3-5030 ,Environmental sciences ,GE1-350 - Abstract
We studied the effect of heavy metal contaminations on genome instability of Chironomus annularius sensu Strenzke from three sampling sites on the River Chechło valley in southern Poland and a control site in Saraya, Bulgaria. The analysis of the heavy metal concentrations in sediments at the three river sites indicated concentrations higher than those in the fossil reference data (Zn 83-160 times, Pb 64-250 times, and Cd 210-793). According to the geoaccumulation index (Igeo), the sediments at all Chechło stations were classified as extremely polluted (Igeo class 6) by Cd, Pb and Zn while they were much less polluted by Cu (classes 1-3). The concentration of Cd, Pb and Zn in the sediments studied exceeded 21-79, 11-44 and 18-34 times the toxic effect threshold (TET) respectively; therefore, the sediments potentially have detrimental effects on the fauna. Genome instability was determined by somatic structural chromosome alterations (mainly heterozygous inversions) in the salivary gland chromosomes of C. annularius. On the basis of the number and frequency of these aberrations the somatic (S) and cytogenetic (C) indices were calculated as these indices allow a better quantification of the impact of heavy metals on organisms living in sediments. In the three Chechło sampling sites somatic aberrations occurred at a frequency significantly higher than in the control site (P
- Published
- 2018
- Full Text
- View/download PDF
4. Long-term retainment of some chromosomal inversions in a local population of Belgica antarctica Jacobs (Diptera, Chironomidae)
- Author
-
Artem Dzhulai, Julia Ilkova, Paraskeva Michailova, Iryna Kozeretska, and Pavlo Kovalenko
- Subjects
Belgica antarctica ,education.field_of_study ,Polytene chromosome ,biology ,Heterochromatin ,fungi ,Population ,Chromosome ,biology.organism_classification ,Chironomidae ,Genome ,Evolutionary biology ,General Earth and Planetary Sciences ,Genetic variability ,General Agricultural and Biological Sciences ,education ,General Environmental Science - Abstract
Genome of antarctic endemic Belgica antarctica Jacobs has been sequenced. However, no set of inversion diagnostic markers has ever been assigned for the species. Using the classical method of polytene chromosome squash preparation, we found three heterozygous inversions located on the second (two heterozygous inversions) and third chromosomes (one heterozygous inversion) in the Belgica antarctica population of a cape o f Wiencke Island, 5 00 m to SW from Port Lockroy. The chromosome set and chromosome variability did not differ from those described in the literature (Atchley and Davis 1979). Every salivary gland chromosome ha d its own markers by which it can be determined. However, we did not find a sex-linked inversion on chromosome III and heterozygous inversion on chromosome I, reported in earlier studies . For the first time , we observed a strong heterochromatin band in chromosome III at the telomere of one arm. Our data show not only the stability of the described inversions in the population but also the usefulness of the squash preparation technique in the studies of genetic variability of Belgica antarctica in present time .
- Published
- 2021
5. Does the subfossil Chironomidae in sediments of small ponds reflect changes in wastewater discharges from a Zn–Pb mine?
- Author
-
Andrzej Kownacki, Julia Ilkova, Agnieszka Pociecha, Dariusz Ciszewski, Ewa Szarek-Gwiazda, and Paraskeva Michailova
- Subjects
chemistry.chemical_classification ,010506 paleontology ,Subfossil ,biology ,Sediment ,Polypedilum ,Tanypodinae ,010502 geochemistry & geophysics ,biology.organism_classification ,01 natural sciences ,Chironomidae ,Mining ,Head capsules ,Nutrient ,Heavy metals ,chemistry ,Orthocladiinae ,Environmental chemistry ,Cores ,Organic matter ,0105 earth and related environmental sciences ,Earth-Surface Processes - Abstract
This study was aimed to show whether subfossil Chironomidae (Diptera) may be useful tool for assessing toxicity of heavy metals in the aquatic environment. Investigations were carried out in subsidence ponds affected by the activity of metal mining: (1) the older ones formed before mining activity and (2) the younger one formed after the mine was closed. Waters of ponds were analyzed for physico-chemical parameters, whereas sediments were studied for metals (Cd, Pb, and Zn), pH, organic matter, nutrients (TOC, N-tot, and P-tot), and subfossil Chironomidae. High concentrations of Cd 6.7–612 μg g−1, Pb 0.1–10.2 mg g−1, and Zn 0.5–23.1 mg g−1 were found in the seven analyzed sediment cores. In total, 374 head capsules of Chironomidae larvae, belonging to four subfamilies Chironominae, Orthocladiinae, Tanypodinae, and Prodiamesinae, were determined. Both the diversity and density of Chironomidae change in particular sediment cores and layers. However, these changes were not related to metal concentrations, as shown in the statistical calculations (dendrogram of similarities, Mann-Whitney test, Spearman correlations). The only exception was the negative correlations between Cd, Pb, and Zn concentrations and the density of head capsules of Polypedilum sp. We found that organic matter and nutrient contents were important factors that control the spatial distribution of subfossil Chironomidae, mainly Orthocladiinae. Other factors which may influence subfossil Chironomidae distribution in sediment cores are discussed. To sum up, despite very high Cd, Pb, and Zn concentrations, the Chironomidae community was not clearly altered, therefore subfossil Chironomidae taxa appeared to be not useful for reconstructing dozen-years scale changes in the toxicity of the aquatic environment.
- Published
- 2020
6. External Morphology of Larvae of Belgica antarctica Jacobs, 1900 (Diptera, Chironomidae) Obtained from Two Locations in Maritime Antarctica
- Author
-
Peter Convey, Paraskeva Michailova, Julia Ilkova, Iryna Kozeretska, Volodymyr A. Gorobchyshyn, and Pavlo Kovalenko
- Subjects
0106 biological sciences ,animal structures ,Clypeus ,Science ,posterior parapods ,Zoology ,Biology ,010603 evolutionary biology ,01 natural sciences ,Chironomidae ,Mentum ,Mandible (arthropod mouthpart) ,parasitic diseases ,clypeus ,14. Life underwater ,Belgica antarctica ,Larva ,Communication ,010604 marine biology & hydrobiology ,fungi ,Mouthparts ,Antennae ,biology.organism_classification ,pecten epipharyngis ,Arthropod mouthparts ,antennae ,Insect Science ,Midge ,mouthparts - Abstract
Simple Summary The chironomid midge Belgica antarctica Jacobs is endemic to the western Antarctic Peninsula and South Shetland Islands. We provide the first detailed photomicrographic images of the fourth-instar larval head capsule and posterior parapods. We assessed variation in the morphology of larvae from two different collection locations off the coast of the western Antarctic Peninsula and compared it with that available in the literature. A number of differences were identified relating to the size of the larvae, the number of teeth on the mandibles, the number of antennal segments and the length of the antennal blade. Malformations of the mandible and mentum are reported for the first time in this species. Abstract The external morphology of the fourth-instar larva of the Antarctic endemic chironomid midge Belgica antarctica is described. Larvae were collected from Jougla Point (Wiencke Island) and an un-named island close to Enterprise Island, off the coast of the western Antarctic Peninsula. Light microscopy was used to examine and document photographically the structures of the mouthparts (mandible, mentum, premandible, labrum), antennae, pecten epipharyngis, clypeus, frontal apotome and posterior parapods. Measurements of the mouthparts are presented. The data obtained are compared with that available in the literature. A number of differences were identified relating to the size of the larvae, the number of teeth on the mandibles, the number of antennal segments and the length of the antennal blade. Malformations of the mandible and mentum are reported for the first time in this species. Features of larvae of taxonomic value that can be used to determine the species in larval stages are presented. These are of utility in using the larvae to reveal relationships with other species. Larvae are also important in ecological and genotoxicological studies, which require accurate species level identification.
- Published
- 2021
7. In Memoriam: Professor Iya Kiknadze (1930–2017)
- Author
-
Ninel Petrova, Snejana Grozeva, Valentina G. Kuznetsova, Julia Ilkova, and Paraskeva Michailova
- Subjects
0106 biological sciences ,lcsh:Genetics ,lcsh:QH426-470 ,In Memoriam ,010604 marine biology & hydrobiology ,Genetics ,Library science ,Animal Science and Zoology ,Plant Science ,Professor Iya Kiknadze ,Biology ,01 natural sciences ,Biotechnology - Abstract
In Memoriam: Professor Iya Kiknadze (1930–2017)
- Published
- 2018
8. Prodiamesa olivacea Meigen and Prodiamesa bureshi Michailova (Diptera, Chironomidae, Prodiamesinae) as a candidate for assessing the genotoxicity of trace metals in fluvial sediments
- Author
-
Ewa Szarek-Gwiazda, Dariusz Ciszewski, Julia Ilkova, Paraskeva Michailova, and Andrzej Kownacki
- Subjects
Geologic Sediments ,010504 meteorology & atmospheric sciences ,Somatic cell ,Zoology ,010501 environmental sciences ,Management, Monitoring, Policy and Law ,medicine.disease_cause ,01 natural sciences ,Chironomidae ,Mentum ,Chromosomes ,Rivers ,Metals, Heavy ,Toxicity Tests ,medicine ,Animals ,Ecotoxicology ,0105 earth and related environmental sciences ,General Environmental Science ,Chromosome Aberrations ,Polytene chromosome ,biology ,Chromosome ,General Medicine ,Prodiamesa olivacea ,biology.organism_classification ,Pollution ,Trace Elements ,Metals ,Larva ,Poland ,Environmental Pollution ,Water Pollutants, Chemical ,Genotoxicity ,DNA Damage ,Environmental Monitoring - Abstract
The genome response, realized by structure chromosome rearrangements in the polytene chromosomes of two sibling species Prodiamesa bureshi Michailova and Prodiamesa olivacea Mg., was studied. The larvae of the species were collected in May and September, 2016, from Biala Przemsza River, a metal-mine-affected site in southern Poland, where Zn, Cd, and Pb concentrations in the sediment exceeded many times the reference data and those from unpolluted sites. The water had high contents of different major ions and nutrients. A high spectrum of somatic chromosome aberrations was detected in the salivary gland chromosomes of both species, which defined a high somatic index (from 1.2 to 7), indicating the sensitivity of both genomes to anthropogenic stress. The cells with somatic rearrangements of both species were significantly higher (P. bureshi: G = 25.636, P
- Published
- 2018
9. Genome instability in Chironomus annularius sensu Strenzke (Diptera, Chironomidae): A biomarker for assessment of the heavy metal contaminants in Poland
- Author
-
Julia Ilkova, Andrzej Kownacki, Dariusz Ciszewski, Paraskeva Michailova, and Ewa Szarek-Gwiazda
- Subjects
Genome instability ,010504 meteorology & atmospheric sciences ,Zoology ,010501 environmental sciences ,Aquatic Science ,01 natural sciences ,Chironomidae ,Sensu ,lcsh:Physical geography ,lcsh:Environmental sciences ,0105 earth and related environmental sciences ,Water Science and Technology ,heavy metals ,lcsh:GE1-350 ,Chironomus annularius ,Ecology ,biology ,genotoxicity ,Metal contaminants ,lcsh:Geography. Anthropology. Recreation ,biomarkers ,biology.organism_classification ,Biomarker ,chromosome aberrations ,lcsh:G ,Environmental science ,lcsh:GB3-5030 - Abstract
We studied the effect of heavy metal contaminations on genome instability of Chironomus annularius sensu Strenzke from three sampling sites on the River Chechło valley in southern Poland and a control site in Saraya, Bulgaria. The analysis of the heavy metal concentrations in sediments at the three river sites indicated concentrations higher than those in the fossil reference data (Zn 83-160 times, Pb 64-250 times, and Cd 210-793). According to the geoaccumulation index (Igeo), the sediments at all Chechło stations were classified as extremely polluted (Igeo class 6) by Cd, Pb and Zn while they were much less polluted by Cu (classes 1-3). The concentration of Cd, Pb and Zn in the sediments studied exceeded 21-79, 11-44 and 18-34 times the toxic effect threshold (TET) respectively; therefore, the sediments potentially have detrimental effects on the fauna. Genome instability was determined by somatic structural chromosome alterations (mainly heterozygous inversions) in the salivary gland chromosomes of C. annularius. On the basis of the number and frequency of these aberrations the somatic (S) and cytogenetic (C) indices were calculated as these indices allow a better quantification of the impact of heavy metals on organisms living in sediments. In the three Chechło sampling sites somatic aberrations occurred at a frequency significantly higher than in the control site (P
- Published
- 2018
10. Implications of Genome Alterations in Chironomus bernensis Klȍtzli (Diptera) for Assessment of Trace Metal Pollution in Two Bulgarian Rivers
- Author
-
Julia Ilkova, Keith N. White, and Paraskeva Michailova
- Subjects
0106 biological sciences ,Pollutant ,Pollution ,geography ,Polytene chromosome ,geography.geographical_feature_category ,Somatic cell ,Ecology ,010604 marine biology & hydrobiology ,media_common.quotation_subject ,Zoology ,Chromosome ,010501 environmental sciences ,Biology ,01 natural sciences ,Genome ,Tributary ,Environmental Chemistry ,Trace metal ,0105 earth and related environmental sciences ,General Environmental Science ,Water Science and Technology ,media_common - Abstract
This study assesses the effect of sediment contaminants as indicated by the measurement of trace metal levels in two large Bulgarian rivers (river Maritsa and a tributary and the river Chaya) on the genome of the abundant chironomid species Chironomus bernensis Klȍtzli. Six trace metals: Cd, Cr, Cu, Mn, Pb and Zn were analysed in the sediments plus the overlying water. The polytene chromosomes of C. bernensis were very sensitive to the pollutants on the basis of numerous somatic chromosome alterations. Two biomarkers based on the degree of somatic structural chromosome alterations—the somatic and cytogenetic indices were applied. Both indices are a sensitive and reproducible approach for assessing the genotoxic effect of contaminants in the sediments. The somatic index from the differentially contaminated sites varied from 1.93 to 2.61, indicating the sensitivity of the C. bernensis genome to anthropogenic stress. The cytogenetic index revealed a high level of pollution in the rivers with a score between 0.27 and 0.37 (
- Published
- 2015
11. Characterization of Heterochromatin in the Salivary Gland Chromosomes of Chironomus riparius Meigen and Chironomus piger Strenzke (Diptera, Chironomidae) by Differential and Fluorochrome Staining
- Author
-
Julia Ilkova, Elżbieta Warchałowska-Śliwa, Anna Maryańska-Nadachowska, and Paraskeva Michailova
- Subjects
Chironomus riparius ,Polytene chromosome ,ved/biology ,Heterochromatin ,ved/biology.organism_classification_rank.species ,Chromosome ,Karyotype ,General Medicine ,Biology ,Molecular biology ,General Biochemistry, Genetics and Molecular Biology ,chemistry.chemical_compound ,chemistry ,Centromere ,Constitutive heterochromatin ,Orcein - Abstract
The constitutive heterochromatin of two homosequential sibling species, Chironomus riparius and Chironomus piger, was studied. The salivary gland chromosomes of both species were analyzed using three staining methods: orcein and C band staining combined with DAPI and CMA3 fluorochrome staining. Both species have the chromosome set 2n = 8, with the same banding pattern and chromosome arm combinations: AB, CD, EF, G, but they differed in number and distribution of heterochromatic bands, AT-rich sequences (DAPI+) and GC-rich sequences (CMA3+). In the polytene chromosomes of C. piger, C-bands were found in centromeres only. They contain two types of repetitive DNA sequences: DAPI+ (very weak) and CMA3+ sequences. However, the polytene chromosomes of C. riparius have many interstitial heterochromatic bands in addition to the centromeric heterochromatin. Some of these bands contain both AT-rich and GC-rich sequences, while others are either AT-rich (DAPI+) or GC-rich (CMA3+). Therefore, these closely related species differ both in the content and localization of constitutive heterochromatin. The species-specific organization of the constitutive heterochromatin can be used as an additional cytogenetic marker for species differentiation.
- Published
- 2015
12. The effect of long-term contamination by heavy metals on community and genome alterations of Chironomidae (Diptera) in a stream with mine drainage water (southern Poland)
- Author
-
Andrzej Kownacki, Urszula Aleksander-Kwaterczak, Julia Ilkova, Pareskeva Michailova, Dariusz Ciszewski, and Ewa Szarek-Gwiazda
- Subjects
Chironomus riparius ,biology ,Ecology ,Somatic cell ,ved/biology ,ved/biology.organism_classification_rank.species ,Chromosome ,Sediment ,Oceanography ,biology.organism_classification ,Chironomidae ,Genome ,Chironomus ,Water quality - Abstract
This paper reports on studies of the effect of heavy metals on the Chironomidae that inhabit the Matylda stream, which has been contaminated for about 100 years by discharge water from a zinc and lead ore mine. Stream sediment was strongly polluted by Cd, Pb, Cu and Zn. These metals did not affect the Chironomidae community but strongly changed the genome system of the Chironomidae species that inhabited the sediment. The salivary gland chromosomes of six species belonging to the two genera Chironomus and Prodiamesa are analyzed. In all species the somatic index is calculated on the basis of somatic chromosome alterations. Chironomus riparius has the highest numbers of somatic alterations and the highest somatic index — 9.67. The smallest chromosome G carries the key structures known as “Balbiani rings”, which play an important role in species development. This chromosome is very sensitive in the genome of the most studied species. The high sensitivity of the C. riparius genome is discussed in light of its DNA organization. The results show a high response of the salivary gland chromosomes to heavy metal pollution, and this makes them a valuable indicator in the assessment of water quality and detection of mutagenic agents in the aquatic environment.
- Published
- 2013
13. Support for the evolutionary speed hypothesis from intraspecific population genetic data in the non-biting midge Chironomus riparius
- Author
-
Julia Ilkova, João Barateiro Diogo, Miklós Bálint, João L.T. Pestana, Ann-Marie Oppold, Markus Pfenninger, and João A.M. Pedrosa
- Subjects
0106 biological sciences ,0301 basic medicine ,Mutation rate ,Climate ,ved/biology.organism_classification_rank.species ,Population ,Biology ,010603 evolutionary biology ,01 natural sciences ,General Biochemistry, Genetics and Molecular Biology ,Intraspecific competition ,Chironomidae ,03 medical and health sciences ,Animals ,education ,Research Articles ,General Environmental Science ,Chironomus riparius ,education.field_of_study ,Genetic diversity ,General Immunology and Microbiology ,ved/biology ,Ecology ,Temperature ,General Medicine ,Biological Evolution ,Europe ,030104 developmental biology ,Haplotypes ,Evolutionary biology ,Ectotherm ,Mutation (genetic algorithm) ,General Agricultural and Biological Sciences ,Neutral theory of molecular evolution ,Animal Distribution - Abstract
The evolutionary speed hypothesis (ESH) proposes a causal mechanism for the latitudinal diversity gradient. The central idea of the ESH is that warmer temperatures lead to shorter generation times and increased mutation rates. On an absolute time scale, both should lead to an acceleration of selection and drift. Based on the ESH, we developed predictions regarding the distribution of intraspecific genetic diversity: populations of ectothermic species with more generations per year owing to warmer ambient temperatures should be more differentiated from each other, accumulate more mutations and show evidence for increased mutation rates compared with populations in colder regions. We used the multivoltine insect speciesChironomus ripariusto test these predictions with cytochrome oxidase I (COI) sequence data and found that populations from warmer regions are indeed significantly more differentiated and have significantly more derived haplotypes than populations from colder regions. We also found a significant correlation of the annual mean temperature with the population mutation parameterθthat serves as a proxy for the per generation mutation rate under certain assumptions. This pattern could be corroborated with two nuclear loci. Overall, our results support the ESH and indicate that the thermal regime experienced may be crucially driving the evolution of ectotherms and may thus ultimately govern their speciation rate.
- Published
- 2016
14. Chromosome variability inChironomus acidophilusKeyl, 1960 from the Afon Goch, UK – a river subject to long-term trace metal pollution
- Author
-
Julia Ilkova, Paraskeva Michailova, Keith N. White, and R. Kerr
- Subjects
Genetics ,Polytene chromosome ,Somatic cell ,Chromosome ,Aquatic animal ,Aquatic Science ,Biology ,medicine.disease_cause ,Telomere ,Insect Science ,medicine ,Trace metal ,Ecology, Evolution, Behavior and Systematics ,Genotoxicity ,Chromosomal inversion - Abstract
The structure and function of the salivary gland polytene chromosomes of the larvae of the chironomid Chironomus acidophilus in a UK river subject to long-term acid (pH
- Published
- 2009
15. Genome instability ofChironomus ripariusMg. andChironomus pigerStrenzke (Diptera, Chironomidae)
- Author
-
Julia Ilkova, Thomas Hankeln, Erwin R. Schmidt, Paraskeva Michailova, Ninel Petrova, Gabriella Sella, and Keith White
- Subjects
Genetics ,Chironomus riparius ,education.field_of_study ,Polytene chromosome ,biology ,ved/biology ,ved/biology.organism_classification_rank.species ,Population ,Retrotransposon ,biology.organism_classification ,Genome ,Minisatellite ,Chironomus ,General Agricultural and Biological Sciences ,Repeated sequence ,education - Abstract
Intra and interspecific variation was evaluated in two Bulgarian populations (Pancharevo and Koka- lijane) of the two sibling and homosequential species Chironomus riparius Mg. and Chironomus piger Strenzke, by analyzing structural and functional alterations in salivary gland polytene chromosomes. In both species genome in- stability was demonstrated, which was expressed by structural and functional somatic chromosomal alterations. In the C. riparius population from Pancharevo, living in sediments containing high concentrations of Cu, Pb and Zn, salivary gland cells containing somatic rearrangements appeared at a significantly higher frequency (51.92%) than in the Kokalijane C. piger population, living in heavy metal-unpolluted sediments (21.3%). In the C. riparius popu- lation, somatic aberrations were distributed at different points along the chromosomes while in the C. piger popula- tion, somatic rearrangements were concentrated in the pericentromeric regions of chromosomes CD, EF and in proximal part of arms D and F. At the cytological level using FISH analysis, both species can be identified also by the different location of tandem-repetitive minisatellite DNA clusters of Alu and Hinf families, and insertion sites of the LINE retrotransposon NLRCTh1. While location of the former is fixed, NLRCth1 appeared to have both fixed and inter-individually variable positions in both species. On average, 19.0 ± 9.5 insertions of NLRCth1 per individ- ual were observed in C. riparius and 5.57 ± 2.09 in C. piger. In both species locations of minisatellite DNA clusters, NLRCth1 retrotransposons and aberration breakpoints concentrated in proximal regions of chromosomes, and the majority of the breakpoints were located in sections containing blocks of repetitive DNA clusters.
- Published
- 2007
16. Characterization of Heterochromatin in the Salivary Gland Chromosomes of Chironomus riparius Meigen and Chironomuspiger Strenzke (Diptera, Chironomidae) by Differential and Fluorochrome Staining
- Author
-
Paraskeva, Michailova, Julia, Ilkova, Anna, Maryańska-Nadachowska, and Elżbieta, Warchałowska-Śliwa
- Subjects
Species Specificity ,Heterochromatin ,Larva ,Cytogenetic Analysis ,Animals ,Chironomidae ,Salivary Glands ,Chromosome Banding - Abstract
The constitutive heterochromatin of two homosequential sibling species, Chironomus riparius and Chironomus piger, was studied. The salivary gland chromosomes of both species were analyzed using three staining methods: orcein and C band staining combined with DAPI and CMA3 fluorochrome staining. Both species have the chromosome set 2n = 8, with the same banding pattern and chromosome arm combinations: AB, CD, EF, G, but they differed in number and distribution of heterochromatic bands, AT-rich sequences (DAPI+) and GC-rich sequences (CMA3+). In the polytene chromosomes of C. piger, C-bands were found in centromeres only. They contain two types of repetitive DNA sequences: DAPI+ (very weak) and CMA3+ sequences. However, the polytene chromosomes of C. riparius have many interstitial heterochromatic bands in addition to the centromeric heterochromatin. Some of these bands contain both AT-rich and GC-rich sequences, while others are either AT-rich (DAPI+) or GC-rich (CMA3+). Therefore, these closely related species differ both in the content and localization of constitutive heterochromatin. The species-specific organization of the constitutive heterochromatin can be used as an additional cytogenetic marker for species differentiation.
- Published
- 2015
17. Functional and structural rearrangements of salivary gland polytene chromosomes of Chironomus riparius Mg. (Diptera,Chironomidae) in response to freshly neutralized aluminium
- Author
-
Julia Ilkova, Keith N. White, and Paraskeva Michailova
- Subjects
Somatic cell ,Health, Toxicology and Mutagenesis ,Centromere ,ved/biology.organism_classification_rank.species ,Toxicology ,medicine.disease_cause ,Chironomidae ,Salivary Glands ,Nucleolus Organizer Region ,medicine ,Animals ,Water Pollutants ,Chromosome Aberrations ,Chironomus riparius ,Genetics ,Polytene chromosome ,biology ,Salivary gland ,ved/biology ,Chromosome ,General Medicine ,biology.organism_classification ,Pollution ,Molecular biology ,medicine.anatomical_structure ,Larva ,Chromosome Inversion ,Environmental Pollutants ,Nucleolus organizer region ,Genotoxicity ,Aluminum - Abstract
Although recent work has shown that environmentally relevant concentrations of freshly neutralized aluminium (AI) are bioavailable and toxic to freshwater invertebrates, the genotoxicity of Al has not been examined. Here we show that freshly neutralized Al affects structure and function of the salivary gland polytene chromosomes of the ubiquitous chironomid larva Chironomus riparius over three generations. Exposure to 500 μg l −1 added Al for 24–25 days resulted in a significantly higher frequency of numerous somatic aberrations, while no structural aberrations were found in F1 controls and few in the second and third generation. Aberrations also included deletions of sections of chromosome G of C. riparius larvae as well as deletions of one or more Balbiani rings. Changes in functional activity included decreased activity of the Balbiani rings (BR), and an increase in the number of decondensed centromeres. The activity of the nucleolar organizer (NOR) significantly decreased in F1 chironomids exposed to Al, while in the F2 and F3 generations the NOR showed normal (high) activity. First generation chironomids were generally more susceptible to Al although no clear evidence of tolerance was apparent over three generations. The possible use of alterations in chironomid polytene chromosomes as biomarkers of trace metal pollution is discussed.
- Published
- 2003
18. Chromosomal Breakpoints and Transposable-elemen tinsertion Sites in Salivary Gland Chromosomes of Chironomus riparius Meigen (Diptera, Chironomidae) from Trace Metal Polluted Stations
- Author
-
Julia, Ilkova, Cervella, Piero, Giampaolo, Zampicinini, Sella, Gabriella, and Paraskeva, Michailova
- Published
- 2013
19. Structural and functional alterations in salivary gland chromosomes and enzyme activity of Chironomus riparius Mg. (Diptera, Chironomidae) from anthropogenically polluted sites in Bulgaria and Turkey
- Author
-
Ridvan Berber, Julia Ilkova, Mustafa Duran, Erdal Karadurmus, Paraskeva Michailova, Alaatin Sen, and [Belirlenecek]
- Subjects
Somatic cell ,ved/biology.organism_classification_rank.species ,Zoology ,Chironomidae ,Genetics ,Metallothionein ,Enzyme activity ,Chironomus riparius ,Pollutant ,Polytene chromosome ,biology ,Ecology ,ved/biology ,Polytene chromosomes ,Cnidoscolus chayamansa ,Diptera ,Balbiani rings ,Chromosome ,Nucleolar organizer ,biology.organism_classification ,Enzyme assay ,Somatic alterations ,biology.protein ,General Agricultural and Biological Sciences - Abstract
The effect of environment contaminants on genome instability and changes in enzyme activity (acetylcholinesterase (AChE), glutathione S-transferase activities (GST), etoxyresorufin O-deethylase (EROD) and metallothionein (MT)) of Chironomus riparius Mg. from Bulgarian and Turkish stations over two years (2009, 2010) as well as laboratory reared larvae were studied. Physicochemical analysis of the sediments from the field stations indicated the presence of heavy metal pollutants (Cr, Cu, Mn, Pb, and Cd) whose concentrations were higher than the reference data. Genome instability was determined by somatic structural and functional alterations of the polytene chromosomes. In the field sites of both countries somatic aberrations occurred at a significantly higher frequency (p < 0.001) compared with control and laboratory material. C. riparius in sediments with higher concentrations of trace metals (Derincay River, Turkey and Chaya River, Bulgaria), was found to possess a high spectrum of somatic chromosome rearrangements with a somatic index of 2.53 and 3.25 respectively. Changes in functional activity included decreased activity of the Balbiani rings (BRs) and nucleolar organizer (NOR). The observed chromosome alterations agree with the high degree of trace metal pollution and high activity of the studied enzymes. However, no correlation between single somatic chromosome rearrangements and concentrations of specific metal ions was defined. The data are discussed in the light of the wide variety of interactions of metals in nature. The results show that the genome response and biochemical markers are sensitive markers of toxicity and provide early warning indicators of contaminants in the environment. Bulgarian Ministry of Education and Sciences [02-259/08]; Bulgarian Academy of Sciences [108Y215]; TUBITAKTurkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) [108Y215] This study was supported by a grant of the Bulgarian Ministry of Education and Sciences to Project DO, 02-259/08 as well as through an exchange Scientific Program between the Bulgarian Academy of Sciences and TUBITAK 108Y215. WOS:000310431900012
- Published
- 2012
20. Genome response of model invertebrates and vertebrates species to stress agents in the environment
- Author
-
Mustafa Duran, E. Karadurmus, Tsenka Chassovnikarova, Julia Ilkova, Nasko Atanasov, Paraskeva Michailova, and Hitit Üniversitesi, Mühendislik Fakültesi, Kimya Mühendisliği Bölümü
- Subjects
ved/biology.organism_classification_rank.species ,Biology ,Genome ,Microtus arvalis ,Chironomidae ,Chromosome rearrangements ,biology.animal ,Microtus ,Chironomus riparius ,Genetics ,Polytene chromosome ,C. Riparius ,Apodemus flavicollis [Small rodents] ,ved/biology ,Chromosome ,Vertebrate ,Microtus Arvalis ,Chromosome Rearrangements ,biology.organism_classification ,Small Rodents ,Apodemus ,C. riparius ,Nucleolus organizer region ,Apodemus Flavicollis ,Biotechnology - Abstract
The genome response of model invertebrate and vertebrate species to stress agent in the environment was studied. The both group of species were collected from contaminated water stations along Marisa (Kemera) and Chaya (Asenovgrad) Rivers and terrestrial areas near Asenovgrad. The structural and functional alterations of the salivary gland chromosomes of Chironomus riparius as well as the aberrations of mitotic chromosomes of Apodemus flavicollis and Microtus arvalis were analyzed. In the polytene chromosomes of C. riparius a high spectrum of somatic aberrations were detected, which appeared in significantly higher frequency in comparison of the control (Kemera: G=37.99, df=1, P
- Published
- 2010
21. Somatic breakpoints, distribution of repetitive DNA and non-LTR retrotransposon insertion sites in the chromosomes of Chironomus riparius Strenkze (Diptera: Chironomidae)
- Author
-
Julia Ilkova, Giampaolo Zampicinini, A. Selvaggi, Erwin R. Schmidt, Paraskeva Michailova, Gabriella Sella, and T. Hankeln
- Subjects
Genetics ,Polytene chromosome ,Retroelements ,Genome, Insect ,Alu element ,Chromosome Breakage ,Retrotransposon ,Locus (genetics) ,Plant Science ,General Medicine ,Biology ,Genome ,Chironomidae ,Minisatellite ,Larva ,Insect Science ,Animals ,Animal Science and Zoology ,Chromosome breakage ,Repeated sequence ,In Situ Hybridization, Fluorescence ,Repetitive Sequences, Nucleic Acid ,Short Interspersed Nucleotide Elements - Abstract
Structural aberrations, their frequency and distribution as well as distribution of the tandem repetitive minisatellite DNA clusters of Alu and Hinf elements and two retroelements, the LINE NLRCth1 and the SINE CTRT1, were analyzed in the genome of the chironomid C. piger Strenzke larvae from a Bulgarian population. A consistent somatic variability in the structure of the polytene chromosomes was detected, showing that the C. piger genome is more actively rearranging than supposed before. Breakpoints were concentrated in proximal parts of chromosomes significantly more often than in distal parts. By FISH analysis we could detect only one locus containing Alu elements and 38 Hinf cluster loci which appear to be dispersed equally all over the chromosomes. The retrotransposons NLRCth1 and CTRT1 are present only in a few loci, but highly variant among different individuals. The mean number of NLRCth1 sites per individual was 18.4 +/- 2.09 and of CTRT1 was 54.8 +/- 8.42. A third of breakpoint locations were close to or coincide with a locus occupied by a retroelement (either NLRCth1 or CTRT1). Nineteen percent of breakpoints coincided with Hinf repetitive DNA elements. Some breakpoints were identical in the two sibling species C. piger and C. riparius Meigen (syn.: C. thummi thummi) and are considered as conserved hot spots of chromosome breakage.
- Published
- 2009
22. Genotoxic effect of copper on salivary gland polytene chromosomes of Chironomus riparius Meigen 1804 (Diptera, Chironomidae)
- Author
-
S. Brunetti, Julia Ilkova, Keith N. White, Ninel Petrova, Paraskeva Michailova, S. Bovero, and Gabriella Sella
- Subjects
Health, Toxicology and Mutagenesis ,ved/biology.organism_classification_rank.species ,Centromere ,Toxicology ,medicine.disease_cause ,Chironomidae ,Salivary Glands ,Toxicity Tests ,medicine ,Animals ,Genetics ,Chironomus riparius ,Chromosome Aberrations ,Polytene chromosome ,biology ,Salivary gland ,ved/biology ,Chromosome ,General Medicine ,Telomere ,biology.organism_classification ,Pollution ,Molecular biology ,medicine.anatomical_structure ,Karyotyping ,Larva ,Toxicity ,Cytogenetic Analysis ,Genotoxicity ,Copper ,Water Pollutants, Chemical - Abstract
The genotoxic action of copper (Cu) on the polytene chromosomes of Chironomus riparius was investigated by analysing structural and functional chromosome aberrations of fourth instars larvae hatched from eggs subject to acute (48 h) exposure with three environmentally relevant concentrations of aqueous Cu (0.005, 0.01, 0.05 mg/l). A dose dependent relationship was observed between Cu concentration and frequency of chromosomal aberrations. A significantly higher frequency of functional alterations, specifically decondensed centromeres and telomeres, and reduction in activity of Balbiani rings, was observed in treated material compared to control. A comparison of breakpoints resulting from treatment with chromium and lead from earlier studies with those Cu-induced identified a series of chromosomal weak points particularly vulnerable to trace metals. We also show that the appearance of structural and functional chromosome aberrations are more sensitive indicators of acute Cu toxicity in chironomid larvae than changes in external morphology.
- Published
- 2006
23. Cytogenetic alterations in Prodiamesinae species (Diptera, Chironomidae) from different polluted regions
- Author
-
Paraskeva V, Michailova, Julia, Ilkova, and Keith, White
- Subjects
Chromosome Aberrations ,Genome ,Transcription, Genetic ,Larva ,Metals, Heavy ,Animals ,Water Pollutants ,Chironomidae ,DNA Damage - Abstract
Changes in the salivary gland chromosomes are described in sibling species Prodiamesa olivacea Mg. and P. bureshi Michailova larvae collected from trace metal polluted and unpolluted areas in Bulgaria and the United Kingdom. Although both species from polluted and unpolluted areas show a high frequency of ectopic conjugations, those between arm B (telomere) and arm F occur at a significantly higher frequency in P. bureshi from unpolluted sites. The reasons for chromosome conjugations and their changes under stress conditions are discussed. Regression of the puffin section 2 of chromosome arm A was significantly higher in P. bureshi from polluted sites, suggesting that trace metal pollution represses transcription at that site. Also, somatic heterozygous inversions and deficiencies occur in chromosomes of both species at the polluted areas. Some deformities ofthe head capsule were observed in both species at the metal-polluted sites. However, our data shows that the genome is a much more sensitive indicator of trace metal pollution than external morphology. The present authors suggest that measuring genotoxic damage at a cellular level provides a subtle and cost-effective indicator of trace metal pollution.
- Published
- 2003
24. Somatic breakpoints, distribution of repetitive DNA and non-LTR retrotransposon insertion sites in the chromosomes of Chironomus piger Strenzke (Diptera, Chironomidae).
- Author
-
Paraskeva Michailova, Julia Ilkova, Tom Hankeln, Erwin Schmidt, Anna Selvaggi, Giampaolo Zampicinini, and Gabriella Sella
- Abstract
Abstract Structural aberrations, their frequency and distribution as well as distribution of the tandem repetitive minisatellite DNA clusters of Alu and Hinf elements and two retroelements, the LINE NLRCth1 and the SINE CTRT1, were analyzed in the genome of the chironomid C. piger Strenzke larvae from a Bulgarian population. A consistent somatic variability in the structure of the polytene chromosomes was detected, showing that the C. piger genome is more actively rearranging than supposed before. Breakpoints were concentrated in proximal parts of chromosomes significantly more often than in distal parts. By FISH analysis we could detect only one locus containing Alu elements and 38 Hinf cluster loci which appear to be dispersed equally all over the chromosomes. The retrotransposons NLRCth1 and CTRT1 are present only in a few loci, but highly variant among different individuals. The mean number of NLRCth1 sites per individual was 18.4 ± 2.09 and of CTRT1 was 54.8 ± 8.42. A third of breakpoint locations were close to or coincide with a locus occupied by a retroelement (either NLRCth1 or CTRT1). Nineteen percent of breakpoints coincided with Hinf repetitive DNA elements. Some breakpoints were identical in the two sibling species C. piger and C. riparius Meigen (syn.: C. thummi thummi) and are considered as conserved hot spots of chromosome breakage. [ABSTRACT FROM AUTHOR]
- Published
- 2009
- Full Text
- View/download PDF
25. Comparative cytogenetic variation of the salivary gland polytene chromosomes in Chironomus riparius Mg., 1804 (Diptera, chironomidae) from two polluted biotopes of Bulgaria and Russia
- Author
-
Julia Ilkova, Paraskeva Michailova, and Ninel Petrova
- Subjects
Chironomus riparius ,Genetics ,Polytene chromosome ,biology ,ved/biology ,Somatic cell ,ved/biology.organism_classification_rank.species ,Breakpoint ,Chromosome ,Chromosomal translocation ,biology.organism_classification ,Chironomidae ,Centromere - Abstract
The structural–functional variation ofChironomus riparius salivary gland polytene chromosomes was studied in two geographically isolated Palearctic regions, Bulgaria (village Pancharevo) and Russia (St. Petersburg). The two biotopes, where larvae were collected, were polluted with various heavy metals from anthropogenic sources. Hereditary paracentric heterozygous inversions were characteristic of the Russian population, whereas somatic paracentric or pericentric heterozygous inversions were more common in the Bulgarian one. All inversions occurred at low frequencies. Other aberrations found in the two populations included somatic deletions resulting in a pompon structure of chromosome IVG, heterozygous translocation between chromosomes IVG and IIIF, enlargement of individual disks, and the appearance of a heterozygous block close to the centromere of chromosome IVG. In addition, changes in functional activity of the nucleolus organizer and Balbiani rings (BRc/BRb) were observed. Several aberration breakpoints proved to coincide with satellites of the Alu and Hinf families.
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.