5933
We have used a full - length cDNA clone of a mouse hepatitis virus strain A59 defective interfering ( DI ) RNA , pMIDI - C , and cassette mutagenesis to study the mechanism of coronavirus subgenomic mRNA synthesis .
 pMIDI - C
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: GENE 
Text: {0} 
Answer:
 pMIDI - C