Characterising the Transcriptomic Response to Interferon and Infection in European Domestic Ferret Respiratory Tissues Using Long‐Read <scp>RNA</scp> Sequencing

The European domestic ferret ( Mustela putorius furo ) is considered the gold standard small animal model for studying human and avian influenza virus infections. However, experimental characterisation of the transcriptomic response to interferon (IFN) stimulation and/or influenza virus infection has been limited, particularly in defining the induction of interferon-stimulated genes (ISGs), with most being computationally predicted. In this study, we present a comprehensive transcriptome-wide assessment of the ferret transcriptome following IFN-α treatment of a ferret lung (FRL) cell line, as well as in nasal turbinates from influenza A virus (IAV)-infected ferrets using long-read RNA sequencing. We have identified a panel of ferret genes orthologous to human ISGs that are upregulated both in response to IFN-α stimulation in vitro and IAV infection in vivo. We have also identified novel IFN-stimulated genes and transcripts. Furthermore, we observed elongation of the poly(A) tails of genes in the ribosome and Coronavirus Disease-19 pathways in response to IFN-α treatment in vitro, suggesting a relationship between poly(A) elongation and the antiviral responses of the host. These results illuminate the dynamics of the transcriptional innate immune response of the domestic ferret and provide an important resource for better utilising ferrets as a small animal model to study influenza virus infections.