Transcriptional gene silencing and heterochromatin spreading in Arabidopsis

• 作 者: ZhizhongGong;
• 机 构: China Agricultural University,Beijing China
• 出 处: 2007年国际多倍体杂种优势及表观遗传学大会
• 发表日期: 2007年期

　　Mutations in the DNA demethylation protein ROS1 cause hypermethylation of the RD29A promoter and transcriptional gene silencing of the RD29A-Luciferase (LUC) transgene.The heterochromatin might spread to cover the linked transgene 35-NPTII and result in its silencing in Arabidopsis thaliana.In order to find out whether the gene silencing mechanisms are same or not between silenced RD29A-LUC and silenced 35S-NPTII,we screened for suppressors of ros1 using the silenced 35S-NPTII and RD29A-LUC as markers and identified several ror mutants (suppressor of ros1).The isolated genes can be divided into three different groups:(1) The mutations only reactivate the silenced35S-NPTII gene but not theRD29A-LUC in the ros1 mutant.(2) The mutations reactivate both the silenced35S-NPTII geneand the RD29A-LUC in the ros1 mutant.(3) The mutations only reactivate the silenced RD29A-LUC but not silenced35S-NPTII gene.