在9月12日的《美国科学院院刊》上，来自美国加州理工学院和加州大学Veterans Affairs医学中心的研究人员描述了一种新的慢病毒(lentiviral)载体平台pSLIK（用于诱导敲除的单慢病毒载体），这种载体能使研究人员通过对任何细胞系统进行单个的病毒感染，并用四环素调节类microRNA短发夹RNA的表达。
越来越多的证据表明RNAi技术是对哺乳动物基因组功能分析的一种强大的实验工具。研究人员通过寻找能够使内源基因表达调节与外源转入基因的再次协同表达的方法将会揭示出这种技术的全部潜能。
在PNAS上的这篇新文章中，研究人员描述了一个新的慢病毒载体平台pSLIK的研发过程。
在小鼠胚胎纤维原细胞中，pSLIK平台能够被用来选择性地抑制heterotrimeric G蛋白G 12 和/或 G 13的表达，并且证实G 13的转录依赖血清应答成分。
在RAW264.7巨噬细胞中，G 2的调节性敲除与钙离子对C5a的反应下降相一致。在G 2的类microRNA短发夹RNA上游插入GFP（绿色荧光蛋白基因）基因能使一个异源mRNA在利用四环素进行靶向基因敲除时发生再次表达。这种做法明显提高了pSLIK系统的实际操作的可行性。
部分英文原文：
A single lentiviral vector platform for microRNA-based conditional RNA interference and coordinated transgene expression
RNAi is proving to be a powerful experimental tool for the functional annotation of mammalian genomes. The full potential of this technology will be realized through development of approaches permitting regulated manipulation of endogenous gene expression with coordinated reexpression of exogenous transgenes. We describe the development of a lentiviral vector platform, pSLIK (single lentivector for inducible knockdown), which permits tetracycline-regulated expression of microRNA-like short hairpin RNAs from a single viral infection of any naïve cell system. In mouse embryonic fibroblasts, the pSLIK platform was used to conditionally deplete the expression of the heterotrimeric G proteins G12 and G13 both singly and in combination, demonstrating the G13 dependence of serum response element-mediated transcription. In RAW264.7 macrophages, regulated knockdown of G2 correlated with a reduced Ca2+ response to C5a. Insertion of a GFP transgene upstream of the G2 microRNA-like short hairpin RNA allowed concomitant reexpression of a heterologous mRNA during tetracycline-dependent target gene knockdown, significantly enhancing the experimental applicability of the pSLIK system.
