An in-vitro transcription assay for development of Rotavirus VP7

Background and Objectives: Human rotavirus (RV) is responsible for most cases of acute gastroenteritis in infants, worldwide. Today, in vitro transcription (IVT) assay is widely used to develop efficient RNA for the biological experiments such as gene function analysis and reverse genetics. The aim of this study was to develop optimal full-length transcripts of the VP7 segment, using in vitro transcription assay. Materials and Methods: Special primers were designed in order to synthesize VP7 sequence of sense RNA in the process of IVT using T7 RNA polymerase. RT-PCR was performed using forward and reverse primers, containing T7 promoter sequence and BstUI restriction enzyme site, respectively. In order to synthesize ssRNA VP7, in accordance with the IVT technique, RV4-VP7 fragment was subcloned into PTZ57 R/T plasmid and digested by BstUI enzyme. Results: The sequencing of the VP7 gene showed 99% identity withVP7 gene of rotavirus RV4 strain (Sequence ID: M64666.1). The analysis of purity of DNA fragment and ssRNA VP7 segment revealed that OD ratio of A260/A280 and quantity of nucleic acids were (1.9, 0.036 μg/μL) and (2.02, 0.98 μg/μL), respectively. Conclusion: In the present study, a modified methodology of RNA synthetase was described by IVT assay, using T7RNA polymerase in order to transcribe the full-length transcripts of human VP7-RV4 strain. This method is applicable for reverse genetic approaches, especially for the production of reassortant RV vaccine.