Objective The objective of the project is to analyze the relationship between the exposure to genotoxic chemicals and the induction of genetic effects in several genotoxicity assays as they are used under laboratory conditions. A series of model compounds which include methylating and ethylating agents were used to determine the nature and the frequency of different types of deoxyribonucleic acid (DNA) damage caused by the chemicals. To this end several assay systems were first developed to measure DNA adduct frequencies. These include immunological assays, high performance liquid chromatography (HPLC) procedures using an electrochemical detector and an enzymatic assay.Parallel to the measurements of DNA damage the frequency of mutations was determined in different organisms which include cultured mammalian cells, mouse germ cells, Drosophila, yeast, Escherichia coli and Salmonella typhimurium.The results to date include that measurements of DNA adduct frequencies can give information concerning the mutagenic potency of a genotoxic agent, but these determinations should be accompanied by measurements of the effects of DNA repair mechanisms on the persistence of the DNA lesions. The expected nature of the induced genetic changes can be confirmed by molecular analysis of the DNA sequence changes. Such a combined approach will generate a genotoxicity profile of a chemical or a group of related chemicals, which can be used in risk assessment procedures.The project described in this research proposal is focused on the relationship between the exposure to genotoxic chemicals and the induction of genetic effects in several genotoxicity assays as they are used under laboratory conditions for regulatory purposes. The work proposed can be divided into the following two categories: 1. Investigations concerning the correlation between exposure to chemicals and formation of DNA adducts. This will be investigated in organisms and under conditions which are also used in the test assays for genotoxicity, e.g. bacteria, yeast, mammalian cells in culture, Drosophila, mice and rats. This part of the project can be divided into two parts: a. Further development of methodologies for the detection and quantification of DNA adducts in the genome overall, which will involve: (i) The use of radioactively labelled model compounds which allow the quantification of labelled DNA adducts at low frequency. (ii) Development of HPLC separation systems using an electrochemical detector, which would allow the detection of certain unlabelled adducts. (iii) Isolation and characterization of monoclonal antibodies against DNA containing specific DNA adducts or against a purified DNA adduct itself. (iv) Further development of various types of immunological assays using the newly characterized antibodies. (v) Further development of immuno histochemical methods for the detection of DNA adducts in various organs and cell types of mammals. (vi) Development of a sensitive assay for the measurement of apurinic sites in DNA. (vii) Further development of post-labelling methods for other than bulky DNA adducts. b. Development of methodologies for the detection of DNA adducts in specific DNA sequences. There is evidence that the distribution of DNA adducts over the genome immediately after exposure is not random, but that certain DNA sequences are damaged to a higher extent. Furthermore, removal of certain type of DNA damage from actively transcribed genes is likely to be faster than from the genome overall. 2. Correlation between DNA adduct formation and biological effect. Most chemicals induce more than one type of DNA adduct. The mutagenic properties of each of these type of adducts can vary significantly. Moreover most organisms are equipped with DNA repair mechanisms which remove specific DNA adducts from their genome with varying efficiency. This part of the project can be divided in the following parts: a.Determination of DNA adduct frequencies as a function of time in: Different organs of mice, hamsterand rat, including mouse and rat germ cells. In eukaryotic systems with different DNA repair characteristics. In E. coli and Salmonella typhimurium. b.Determination of molecular mutation spectra of base pair changes under normal and repair deficient conditions. This will allow a direct correlation between the fate of certain DNA adducts and the type of base pair changes induced. Especially the determination of DNA adducts in the same gene to be used for mutation analysis will allow a direct correlation between DNA adduct formation and the type of induced mutations. Fields of science natural sciencesbiological sciencesmicrobiologybacteriologynatural sciencesbiological sciencesgeneticsDNAnatural sciencesbiological sciencesgeneticsmutationnatural sciencesbiological scienceszoologymammalogynatural sciencesbiological sciencesgeneticsgenomes Programme(s) FP3-ENV 1C - Specific research and technological development programme (EEC) in the field of the environment, 1990-1994 Topic(s) 02 - Technologies and engineering for the environment Call for proposal Data not available Funding Scheme CSC - Cost-sharing contracts Coordinator Rijksuniversiteit Leiden Address 72,wassenaarseweg 2300 RA Leiden Netherlands See on map EU contribution € 0,00 Participants (15) Sort alphabetically Sort by EU Contribution Expand all Collapse all Centre International de Recherche sur le Cancer France EU contribution € 0,00 Address 150 cours albert thomas 69372 Lyon See on map Centre National de la Recherche Scientifique (CNRS) France EU contribution € 0,00 Address 39-53 rue camille desmoulins 94805 Villejuif See on map GSF-RESEARCH CENTER FOR ENVIRONMENT AND HEALTH Germany EU contribution € 0,00 Address Ingolstaedter landstrasse 1 85764 Neuherberg See on map ISTITUTO SUPERIORE DI SANITA Italy EU contribution € 0,00 Address Viale regina elena 299 00161 Roma See on map Istituto Nazionale per la Ricerca sul Cancro Italy EU contribution € 0,00 Address Viale benedetto xv 10 16132 Genova See on map NATIONAL HELLENIC RESEARCH FOUNDATION Greece EU contribution € 0,00 Address 48,vas. constantinou avenue 48 11635 Athens See on map Nederlands Kanker Instituut Netherlands EU contribution € 0,00 Address 121,plesmanlaan 1066 CX Amsterdam See on map Nederlandse Organisatie voor Toegepast Natuurwetenschappelijk Onderzoek Netherlands EU contribution € 0,00 Address 137-139,lange kleiweg 2280 HV Rijswijk See on map Rijksinstituut voor Volksgezondheid en Milieuhygiëne Netherlands EU contribution € 0,00 Address 9,antonie van leeuwenhoeklaan 3720 BA Bilthoven See on map Rijksuniversiteit Leiden Netherlands EU contribution € 0,00 Address 2333 AA Leiden See on map Stockholms Universitet Sweden EU contribution € 0,00 Address 106 91 Stockholm See on map UNIVERSIDAD DE CORDOBA Spain EU contribution € 0,00 Address S/n,avenida menéndez pidal s/n 14080 Cordoba See on map UNIVERSITY OF WALES SWANSEA United Kingdom EU contribution € 0,00 Address Singleton park SA2 8PP Swansea See on map Universität Gesamthochschule Essen Germany EU contribution € 0,00 Address Hufelandstraße 55 45147 Essen See on map Universität Wien Austria EU contribution € 0,00 Address 8a,borschkegaße 1090 Wien See on map