SVIBOR - Project code: 1-08-101


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SVIBOR - Collecting Data on Projects in Croatia

Project code: 1-08-101


Main researcher: FRANEKIĆ, JASNA (85870)

Type of research: basic
Duration from: 03/01/91. to 03/01/95.

Papers on project (total): 63
Papers on project quoted in Current Contents: 23
Institution name: Prehrambeno-biotehnološki fakultet, Zagreb (58)
Department/Institute: Department of Biochemical Engineering Laboratory of Biology and Microbial Genetics
Address: Pierottijeva 6
City: 10000 - Zagreb, Croatia
Phone: 385 (01) 417-044
Fax: 385 (01) 411-436
E-mail: jfranek

Summary: The genotoxic effects of different classes of chemicals (model mutagens, non-ionizing radiation, pesticides, drugs and their metabolites) were investigated both in vitro and in vivo. The obtained results support the hypothesis that some carcinogens (ETU) are capable of disturbing the chromosomes segregation through their interaction with non-DNA targets. The aim of this study was to validate the short-term test-system with yeast for the detection of substances capable to induce aneuploidy. Our study has shown that human tumour cells resistant to specific alkylating chemotherapeutic drugs had higher 3-methyladenine DNA glycosilase activity comparing to normal cells. By using shuttle vector methodology and by analyzing mutational spectra induced by potent carcinogen MNU, we investigated the influence of different DNA polymerases involved in the replication process, on the fidelity of replication of DNA strands (in one case leading and in the other lagging one) opposite damage caused by MNU, and therefore, the effects on the mutation frequency and distribution of mutations. The results have shown that different DNA polymerases had no influence on two studied phenomenons. Investigation effects of transcription on UV-induced mutations in mammalian cells showed a clear bias towards the transcribed strand under both basal and induced gpt transcription. The results have shown that in S.typhimurium nucleotide excision repair (NER) is the main DNA repair system operating on cytotoxic and premutagenic DNA lesions induced by monofunctional alkylating agents (MNNG, MMS, ENNG, ENU, PNNG and BNNG). On the chromosomal DNA of S.typhimurium we have not detected nucleotide sequence that could hybridize with alkA gene from E.coli. The aidB gene expression was induced in E.coli (strain MV1161) and in S.typhimurium (strain G46/pMV201) by two studied alkylating agents, MMS and MNNG. The genotoxic effect of pulsed and pulsed color Doppler ultrasound then continuous and pulsed microwave radiation were investigated with microbial test systems for detecting mutation recombination and aneuploidy. Pulsed and pulsed color doppler (intensity 0.59 W/cm2 and frequency 5 MHz) showed the mutagenic activity in strains TA100 and TA98 of bacteria Salmonella typhimurium. Continuous and pulsed microwave radiation power density 16 mW/cm2 and frequency 7.7 GHz caused weak mutagenic effects in strains TA98 and TA1538. Both types of non-ionizing radiation did not induce recombination and aneuploidy during mitosis in yeast Saccharomyces cerevisiae.

Keywords: Salmonella typhimurium, Escherichia coli, Saccharomyces cerevisiae, human cells, alkylating agents, pesticides, drugs, replication, mutation, aneuploidy, nucleotide excision repair, non-ionizing radiation, UV-radiation

Research goals: Biological monitoring consists of detecting, characterizing and evaluating the effects produced in individuals exposed to potential mutagens and/or carcinogens. Pesticides have become a major source of environmental mutagens. Amongst the pesticides tested in vitro and in vivo, many of them as well as their metabolites have been shown mutagenic properties. We have been investigated model chemicals for their ability to induce aneuploidy in yeast Saccharomyces cerevisiae and mound Aspergillus nidulans. We have used a cellular test systems to study the possible correlation between induction of aneuploidy on the onehand and, on the other, inhibition of polymerization mammalian brain tubulin in vitro. Extract of glial cell line (SF-126) which is sensitive to the cytotoxic effect of the haloethylnitrosoureas and cell line (SF-188) which is resistant to these agents have been tested for their ability to release methylated bases from DNA substrate which has been modified with (3H) dimethyl sulphate. In comparatione with the sensitive cell line, extracts from the resistant cell line have 2-3 fold higher enzymatic activity. It is known that one of the sources of mutations may be the replication process itself because of the different fidelity of DNA polymerases conducting the synthesis of leading and lagging strand opposite the damage (in our case an alkylation damage). The use of two "shuttle" vectors with the target gene in opposite orientation relative to the origin of replication give us the opportunity to study the influence of different DNA polymerases on mutation frequency and their distribution. The results have shown that DNA polymerases had no effects on studied phenomenons. According to the program of research we have investigated the low dose effects by monofunctional alkylating agents: MNNG, MNS, ENNG, ENU, PNNG and BNNG. Comparing the S.typhimurium uvrB mutant to nucleotid excision repair-proficient strain it has been noticed that the latter was mutagenized more efficiently at low doses and less efficiently at high doses of methylating and ethylating agents. The starting point of this work was disagreement of scientists about the existence of quantifiable injurious effects of doppler ultrasound and microwave radiation on biological systems. The mutagenic effects of these types of radiation were determined by employing a battery of tests (Ames test) Salmonella typhimurium (strains TA100, TA98, TA97, TA1535, TA1538) and the yeast Saccharomyces cerevisiae (strains D7, D61.M). Plate incorporation assay with S. typhimurium demonstrated direct mutagenicity of pulsed and pulsed color doppler ultrasound 0.59 W/cm2 spatial peak temporal average intensity (SPTA) and frequency 5 MHz. Continous and pulsed microwave radiation power density 16 mW/cm2 and frequency 7. GHz causes a weak mutagenic effect in strains TA98 and TA1538 for detecting frameshift mutations. Pulsed and pulsed collor doppler and continuous and pulsed microwave radiation did not induce aneuploidy (strain D61.M) and recombination (strain D7) during mitosis in yeast S. cerevisiae.


  1. Name of project: EZ/COST 66 Fate of pesticides in the soil and environment
    Name of institution: Commission of the European Communities
    City: Brisel, Belgija


  1. Name of institution: Istituto Superiore di Sanita, Laboratory of Comparative Toxicology and Ecotoxicology
    Type of institution: University/Faculty
    Type of cooperation: Joint publishing of scientific papers
    City: Rim, Italija

  2. Name of institution: Department of Molecular Genetics and Microbiology, University of Massachusetts, Medical School, Worcester,
    Type of institution: Economical/Production
    Type of cooperation: Joint publishing of scientific papers
    City: Massachusetts, USA

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Last update: 10/13/95