Generation of Full-length Infectious cDNA Clones of Middle East Respiratory Syndrome Coronavirus.

Lee, Jeong Yoon; Bae, Sojung; Myoung, Jinjong

Middle East respiratory syndrome coronavirus (MERS-CoV) was first identified in Saudi Arabia in 2012 and its infection has been reported over 20 countries. Roughly 10,000 human cases were reported and fatality reaches up to 40%. The majority of cases occurred in Saudi Arabia and mostly sporadic outside the country except the outbreak in South Korea in 2015. The Korean MERS-CoV isolate was isolated from the second Korean patient and its genome was fully sequenced and deposited. To develop virus-specific protective and therapeutic agents against the Korean isolate and to investigate molecular determinants of virus-host interactions, it is of paramount importance to generate its full-length cDNA. Here we report that two full-length cDNA's of a Korean patient-isolated MERS-CoV strain are generated by combination of the conventional cloning techniques and efficient Gibson assembly reactions. The full-length cDNA's were validated by restriction analysis and its sequence was verified by Sanger method. Resulting cDNA was efficiently transcribed in vitro and showing the T7 promoter-driven expression is robust. The resulting reverse genetic system will add to the published list of MERS-CoV cDNA's and facilitate the development of Korean isolate-specific antiviral measures.