Kumpatla S P, Hall T C
Institute of Developmental and Molecular Biology, and Department of Biology, Texas A&M University, College Station 77843-3155, USA.
Plant Mol Biol. 1998 Dec;38(6):1113-22. doi: 10.1023/a:1006071018039.
Epigenetic silencing of a bialaphos resistance (bar) gene in R1 progeny of a transgenic rice line was found to be meiotically stable since selfed (R2) progeny were also susceptible and the bar locus highly methylated. A high proportion of R2 seedlings germinated in the presence of 5-azacytidine (AzaC) were herbicide-resistant and also contained at least one unmethylated copy of the bar gene, further establishing the relationship between silencing and methylation. Restored bar gene expression was typically maintained for 20-50 days, but eventual methylation and silencing of the bar locus underscores the ability of the recipient genome to recognize and inactivate intrusive DNA.
在一个转基因水稻品系的R1后代中，双丙氨膦抗性（bar）基因的表观遗传沉默被发现具有减数分裂稳定性，因为自交（R2）后代也表现出敏感性，且bar基因座高度甲基化。在5-氮杂胞苷（AzaC）存在的情况下萌发的高比例R2幼苗具有除草剂抗性，并且还含有bar基因的至少一个未甲基化拷贝，这进一步证实了沉默与甲基化之间的关系。恢复的bar基因表达通常维持20至50天，但bar基因座最终的甲基化和沉默突出了受体基因组识别和使侵入性DNA失活的能力。
