Differential usage of RNA templates by the rotavirus "in vitro" replication system

Rotavirus genome synthesis is a two-step process; the synthesis of the eleven viral mRNAs and the production of the complementary strand (minus strand synthesis) yielding the double stranded genomic RNA (dsRNA). Purified rotavirus open cores are a helpful tool to study this replication event. These open cores can use viral dsRNA and mRNAs as template for RNA synthesis. In the present communication it was demonstrated that open cores prefers to use viral mRNA as template instead of the genomic dsRNA. The use by the open cores of both templates can be blocked through two independent strategies. In the presence of ssRNAs molecules, the use of the viral dsRNA template is completely blocked without affecting the minus strand synthesis. Nevertheless, an antisense oligonucleotide strategy previously reported to block the minus strand synthesis of the target gene do not affect the use of the dsRNA template. These results suggest the recognition of different signals in each template by the open core protein complex.