Duplicated genes are probably inactivated during the premeiotic period between fertilization and karyogamy, but reactivation may occur spontaneously or after 5-azacytidine treatment. The aim of the present study was to determine the action of GIS on a single copy gene located near a duplicated segment. Data show that the GIS can act on a closely linked gene outside the duplicated segment, promoting reversible inactivation. Reduction of ascospore numbers and viability were observed in crosses parented by duplication strains. Aspergillus nidulans , gene inactivation, DNA methylation, chromosomal duplication.
Des souches d' A .
Aspergillus nidulans , inactivation des g nes, m thylation de l'ADN, duplication chromosomique.