In vitro transcription

The plasmids containing the infectious clone of SINV were purified by the Plasmid Maxi Kit (Qiagen, Hilden, Germany), linearized by digestion with NotI (New England Biolabs, Ipswich, MA, USA), and purified by phenol-chloroform extraction. RNAs were then synthesized in an in vitro transcription system by incubating at 37 °C for 1h containing the linearized DNA template, NTP mix, dithiothreitol, RNaseOUT ribonuclease inhibitor, and SP6 RNA polymerase (Thermo Scientific, Waltham, MA, USA). Following DNase I treatment, LiCl Precipitation Solution (Invitrogen) was added to extract the synthesized RNAs.