id author title date pages extension mime words sentences flesch summary cache txt cord-331916-n744pymd Liu, Jue Inhibition of porcine circovirus type 2 replication in mice by RNA interference 2006-04-10 .txt text/plain 6657 350 52 Specific inhibition of endogenous or pathogen mRNA by RNAi can be triggered by the introduction of 21 -23 nucleotide (nt) duplexes of RNA (siRNA) or by transcription of DNA precursor into short hairpin RNAs (shRNA) homologous to target sequences (Brummelkamp et al., 2002; Elbashir et al., 2001a; Paddison et al., 2002) , opening up possibilities for controlling replicative processes of pathogens. To further examine the ability of ORF1 shRNA to suppress viral gene expression in PCV2-infected PK15 cells, single nucleotide mutations were introduced into pSIR3 sequence as shown in Fig. 4A . As shown in Fig. 4B , a mutant with one nucleotide mutation in the 5V-end of the sense strand (pSIR3-m1) still had an effective reduction in the synthesis of ORF1 and ORF2 proteins, whereas with a nucleotide substitution at the center (pSIR3-m2) or 3V-end (pSIR3-m3) of the sense sequence, the resultant shRNAs failed to significantly suppress expression of PCV2 ORF1 and ORF2 in the transfected cells, further verifying the specificity of RNAi as demonstrated (Amarzguioui et al., 2003; Harborth et al., 2003) . ./cache/cord-331916-n744pymd.txt ./txt/cord-331916-n744pymd.txt