Autoregulatory control of CACTA transposon in Arabidopsis thaliana

Abstract

CACTA transposon in Arabidopsis thaliana is silent in wild type background, but it is mobilized by DNA hypomethylation mutation ddm1 (Decrease in DNA Methylation). Once activated by the ddm1 mutation, CACTA remains mobile even after the introduction into wild type background. Interestingly, the transposition frequency of CACTA increased during self-pollination in the ddm1 background. Here we report that the increase was also detectable even after cross to wild type. In addition, DNA methylation level decreased during the activation process of CACTA. Possible molecular mechanisms of this autoregulatory process will be discussed.