Ruiz F, Vayssié L, Klotz C, Sperling L, Madeddu L
Centre de Génétique Moléculaire, Centre National de la Recherche Scientifique, 91198 Gif-sur-Yvette, France.
Mol Biol Cell. 1998 Apr;9(4):931-43. doi: 10.1091/mbc.9.4.931.
Microinjection at high copy number of plasmids containing only the coding region of a gene into the Paramecium somatic macronucleus led to a marked reduction in the expression of the corresponding endogenous gene(s). The silencing effect, which is stably maintained throughout vegetative growth, has been observed for all Paramecium genes examined so far: a single-copy gene (ND7), as well as members of multigene families (centrin genes and trichocyst matrix protein genes) in which all closely related paralogous genes appeared to be affected. This phenomenon may be related to posttranscriptional gene silencing in transgenic plants and quelling in Neurospora and allows the efficient creation of specific mutant phenotypes thus providing a potentially powerful tool to study gene function in Paramecium. For the two multigene families that encode proteins that coassemble to build up complex subcellular structures the analysis presented herein provides the first experimental evidence that the members of these gene families are not functionally redundant.
将仅包含某一基因编码区的质粒以高拷贝数显微注射到草履虫的体大核中，会导致相应内源基因的表达显著降低。到目前为止，在所有检测的草履虫基因中都观察到了这种在整个营养生长过程中稳定维持的沉默效应：一个单拷贝基因（ND7），以及多基因家族的成员（中心蛋白基因和刺丝泡基质蛋白基因），其中所有密切相关的旁系同源基因似乎都受到了影响。这种现象可能与转基因植物中的转录后基因沉默以及粗糙脉孢菌中的基因压制有关，并允许高效创建特定的突变表型，从而为研究草履虫中的基因功能提供了一个潜在的强大工具。对于编码共同组装以构建复杂亚细胞结构的蛋白质的两个多基因家族，本文所呈现的分析提供了首个实验证据，表明这些基因家族的成员在功能上并非冗余。
