Paraskeva VL. Michailova

Learn More
C banding in polytene chromosomes of Chironomus riparius from a Santena polluted station of the river Po, Italy was described. A large variation in the appearance of C bands was established. The process involved the transformation of euchromatin into heterochromatin. Activation of all chromosomes at telomeres was found. A structural modification of(More)
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(More)
Two geographically distant populations of Chironomus riparius (syn. C. thummi) from two environmentally polluted sites (Santena, Italy and Varna, Bulgaria) show numerous somatic and inherited chromosomal aberrations (inversions, deletions and deficiencies). Fifty-five percent of the observed breakpoints occurred in at least two larvae from both populations.(More)
Different frequencies of chromosomal alterations in salivary gland polytene chromosomes AB, CD and EF were described in larvae of Chironomus riparius (syn. Chironomus thummi) from the trace metal-polluted station of Santena on the river Banna, near Turin, and from the unpolluted station of Corio (40 Km from Turin) which was taken as a reference area. In a(More)
The karyotype structure and chromosomal polymorphisms were investigated in 6 natural and 2 laboratory populations of Chironomus nuditarsis from Europe and Asia. The pool of rearranged polytene chromosome banding sequences of this species was determined that includes 16 inversion banding sequences and sequences with giant DNA-knobs (ndtG1k, ndtG2k). Obvious(More)
The orthopteran insect Tetrix tenuicornis, collected from polluted and unpolluted areas, was used to study heavy metal accumulation and its impact on stress protein levels and on changes in the number and morphology of chromosomes in mitotic and meiotic cells. During two consecutive years, insects were collected from polluted areas of zinc-lead mine spoils(More)
A population of Chironomus riparius from a Po river station near Moncalieri (a trace-metal polluted station) was studied. In this population was established a great variability of band structure of polytene chromosomes as well as paracentric heterozygous inversions, deletions, deficiencies, partial breaks, diploid chromosome fragments, and changes in(More)
The genotoxicity of trace metals in the sediments from a number of polluted sites on UK and Bulgarian rivers to Chironomus piger was assessed by an examination of genome instability as demonstrated by structural and functional changes to the salivary glands chromosomes. Based on the metal assays, the sediments were characterized to range from 'extremely' to(More)
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(More)
Endochironomus tendens has been studied from different localities and geographically isolated populations. On the basis of the detailed karyotaxonomic analysis the investigated material can be divided into two forms. These forms are distinguished by their karyotype and phenotype. The results of the karologica and hybridization analysis showed that the(More)