RNA changes are observed on specific cell RNA residues and play a key role in their maturation and functionality. Of the chemical changes described, nucleotide methylation is the most abundant. In the cell, cytoplasmic sensors recognise unmodified exogenous RNAs and activate the production of type I interferon to establish an antiviral state. Some posttranscriptional changes in viral RNA such as the m6A modification found in viruses such as Hepatitis C and Zika and affect the replication and activation of the antiviral response. During infections with human immunodeficiency viruses, herpes associated with Kaposi sarcoma and flu, these viral RNAs contain m6A changes, affecting viral replication. The impact of posttranscriptional changes in viral genomic RNA (gRNA) during infection and the innate immune response remain unknown to date. The objectives are: (I) map RNA changes of different RNA viruses (flavivirus, alphavirus, rhabdovirus and picornavirus) during the viral cycle; (II) determine changes in gRNA on the biogenesis and maturation of the viral genome in the organelles of the human cell; (III) to study the changes identified on the recognition of viral genomes by RLR sensors and the activation of the type I interferon pathway in the target cell.