Two classes of small antisense RNAs in fungal RNA silencing triggered by non-integrative transgenes
Two classes of small antisense RNAs in fungal RNA silencing triggered by non-integrative transgenes
复制标题
DOI：
10.1093/emboj/cdg384
复制
发表时间：
2003-08-01
期刊：
影响因子：
11.4
通讯作者：
Ruiz-Vázquez, RM
中科院分区：
文献类型：
--
作者：
Nicolás, FE;Torres-Martínez, S;Ruiz-Vázquez, RM
卷枝毛霉转化含有野生型拷贝的胡萝卜素基因carB的自我复制质粒导致沉默的carB功能在3%的转化体。基因组分析揭示了沉默的表型和质粒拷贝数之间的关系。这种表型由carB mRNA的稳态水平降低引起，这种降低不是由于转录水平的差异，表明沉默是转录后的。已发现小的有义和反义RNA与卷枝霉中的基因沉默相关。两个大小类的小反义RNA，差异积累在营养生长的沉默转化体，已被检测到：长25个核苷酸的RNA和短21个核苷酸的RNA。还检测到与初始触发分子下游的内源基因序列对应的次级有义和反义RNA，揭示了RNA靶向在真菌中的扩散的存在。这些发现，再加上触发分子的自我复制性质，使卷枝霉成为研究RNA沉默中一些尚未解决的问题的合适生物体。
Transformation of Mucor circinelloides with self-replicative plasmids containing a wild-type copy of the carotenogenic gene carB causes silencing of the carB function in 3% of transformants. Genomic analyses revealed a relationship between silenced phenotype and number of copies of plasmids. This phenotype results from a reduction of the steady-state levels of carB mRNA, a reduction that is not due to differences in the level of transcription, indicating that silencing is post-transcriptional. Small sense and antisense RNAs have been found to be associated with gene silencing in M.circinelloides. Two size classes of small antisense RNAs, differentially accumulated during the vegetative growth of silenced transformants, have been detected: a long 25-nucleotide RNA and a short 21-nucleotide RNA. Secondary sense and antisense RNAs corresponding to sequences of the endogenous gene downstream of the initial triggering molecule have also been detected, revealing the existence of spreading of RNA targeting in fungi. These findings, together with the self-replicative nature of the triggering molecules, make M.circinelloides a suitable organism for investigating some unresolved questions in RNA silencing.