Hybrid cytomegalovirus-U6 promoter-based plasmid vectors improve efficiency of RNA interference in zebrafish.
Short hairpin RNA (shRNA) directed by RNA polymerase III (Pol III) or Pol II promoter was shown to be capable of silencing gene expression, which should permit analyses of gene functions or as a potential therapeutic tool. However, the inhibitory effect of shRNA remains problematic in fish. We demonstrated that silencing efficiency by shRNA produced from the hybrid construct composed of the CMV enhancer or entire CMV promoter placed immediately upstream of a U6 promoter. When tested the exogenous gene, silencing of an enhanced green fluorescent protein (EGFP) target gene was 89.18 +/- 5.06% for CMVE-U6 promoter group and 88.26 +/- 6.46% for CMV-U6 promoter group. To test the hybrid promoters driving shRNA efficiency against an endogenous gene, we used shRNA against no tail (NTL) gene. When vectorized in the zebrafish, the hybrid constructs strongly repressed NTL gene expression. The NTL phenotype occupied 52.09 +/- 3.06% and 51.56 +/- 3.68% for CMVE-U6 promoter and CMV-U6 promoter groups, respectively. The NTL gene expression reduced 82.17 +/- 2.96% for CMVE-U6 promoter group and 83.06 +/- 2.38% for CMV-U6 promoter group. We concluded that the CMV enhancer or entire CMV promoter locating upstream of the U6-promoter could significantly improve inhibitory effect induced by the shRNA for both exogenous and endogenous genes compared with the CMV promoter or U6 promoter alone. In contrast, the two hybrid promoter constructs had similar effects on driving shRNA.
Su
Jianguo
J
State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China.
Zhu
Zuoyan
Z
Xiong
Feng
F
Wang
Yaping
Y
D000818:Animals; D003587:Cytomegalovirus / Q000235:genetics*; D004625:Embryo, Nonmammalian / Q000378:metabolism; D005326:Fetal Proteins; D018507:Gene Expression Regulation, Developmental; D005822:Genetic Vectors / Q000235:genetics*; D010957:Plasmids / Q000235:genetics*; D011401:Promoter Regions, Genetic / Q000235:genetics*; D034622:RNA Interference; D034741:RNA, Small Interfering / Q000235:genetics; D012342:RNA, Small Nuclear / Q000235:genetics*; D020825:T-Box Domain Proteins / Q000235:genetics; D015027:Zebrafish / Q000235:genetics / Q000378:metabolism*; D029961:Zebrafish Proteins / Q000235:genetics; D000098908:Brachyury Protein
D005326:Fetal Proteins; D034741:RNA, Small Interfering; D012342:RNA, Small Nuclear; D020825:T-Box Domain Proteins; D029961:Zebrafish Proteins; D000098908:Brachyury Protein; C405486:U6 small nuclear RNA