title: Aspergillus nidulans as a test organism for the detection of chemically-induced mitotic crossing-over and chromosome malsegregation.
abstract: The genetic systems developed in the mould Aspergillus nidulans to study the chemical induction of mitotic genetic segregation were used to investigate the mechanism of aneuploidy induction by the main benzene hydroxy metabolites. Detailed genetic analysis of mitotic segregants produced by individual colonies revealed the simultaneous occurrence of both whole chromosome segregants and mitotic cross-overs, i.e. a pattern not compatible with the induction of numerical abnormalities as the primary event. Confirmatory evidence was obtained in a haploid strain, thus demonstrating the possible secondary origin of aneuploidy following the induction of structural chromosome damages. Furthermore, mutagenic, lethal and growth-arresting properties of a series of chlorinated hydrocarbons were quantitatively estimated and compared to a series of physico-chemical descriptors of the molecules to assess the possible role of unspecific physical interactions in their mechanism of action. The analysis of the interrelationships among these variables highlighted a possible correlation among physico-chemical descriptors and toxic properties and a dissociation of the aneugenic activity with the other chemical and biological descriptors.
authors.forename: R
authors.initials: R
authors.lastname: Crebelli
mesh_terms: D001233:Aspergillus nidulans / Q000187:drug effects / Q000235:genetics*; D002875:Chromosomes / Q000187:drug effects*; D003434:Crossing Over, Genetic / Q000187:drug effects*; D006843:Hydrocarbons, Chlorinated / Q000494:pharmacology; D006846:Hydrocarbons, Halogenated / Q000494:pharmacology*; D066298:In Vitro Techniques; D008938:Mitosis / Q000187:drug effects*; D010636:Phenols / Q000494:pharmacology*
chemical_list: D006843:Hydrocarbons, Chlorinated; D006846:Hydrocarbons, Halogenated; D010636:Phenols