Effect of 5-Azacytidine on the Induction of Mitotic Recombination in Diploid Cells of Aspergillus nidulans

Abstract

5-Azacytidine is a cytidine analogue whose incorporation into DNA leads to DNA hypomethylation. This 5-azacytidine effect results in alterations in a variety of gene functions including cellular differentiation and gene expression. The aim of this work is to demonstrate the recombinogenic effect of 5-azacytidine. The Aspergillus nidulans master strains UT448 and UT196 were used to produce the UT448//UT196 diploid strain. Conidia of this strain were inoculated in Petri dishes containing selective medium supplemented with 40 or 100 μM 5-azacytidine. The plates were incubated for 5 days at 37°C. Mitotic segregants were isolated from the diploid colonies and phenotypes of the segregants were analyzed. 5-Azacytidine was shown to be positive in inducing somatic crossing-over in diploid cells of A. nidulans. An increase in the mitotic recombination frequencies was observed in several linkage-intervals of chromosomes I and II from UT448//UT196 diploid strain.