Definition: In this task, you're given a paragraph from the research paper and your task is to generate a suitable title for the research paper based on the given paper. Under 100 words is a good title length.
Input: corona-, toro-and roniviruses are evolutionarily related positive-strand RNA viruses, united in the order Nidovirales. The best studied nidoviruses, the corona-and arteriviruses, employ a unique transcription mechanism, which involves discontinuous RNA synthesis, a process resembling similarityassisted copy-choice RNA recombination. During infection, multiple subgenomic (sg) mRNAs are transcribed from a mirror set of sg negative-strand RNA templates. The sg mRNAs all possess a short 5¢ common leader sequence, derived from the 5¢ end of the genomic RNA. The joining of the non-contiguous leader' and`body' sequences presumably occurs during minus-strand synthesis. To study whether toroviruses use a similar transcription mechanism, we characterized the 5¢ termini of the genome and the four sg mRNAs of Berne virus (BEV). We show that BEV mRNAs 3±5 lack a leader sequence. Surprisingly, however, RNA 2 does contain a leader, identical to the 5¢-terminal 18 residues of the genome. Apparently, BEV combines discontinuous and nondiscontinous RNA synthesis to produce its sg mRNAs. Our ®ndings have important implications for the understanding of the mechanism and evolution of nidovirus transcription.

Discontinuous and non-discontinuous subgenomic RNA transcription in a nidovirus