FIG 1.

circMerTK is induced by influenza A virus (IAV) infection in vivo. (A) Ten C57BL/6 mice were divided into two groups and inoculated with phosphate-buffered saline (PBS) or IAV PR8, and lung samples were collected at 2 days postinfection (dpi) for RNA sequencing (RNA-seq) analysis. Differentially expressed circRNAs are shown in the heatmap. (B) The expression of the four selected circRNAs was confirmed by reverse transcription-PCR (RT-PCR) using divergent primers in the lungs and blood samples of IAV PR8- and IAV WSN-challenged mice. (C) Schematic diagram of circMerTK formed by back-splicing from the mouse MerTK gene at chromosome 2. (D) RT-PCR was used to determine circMerTK, MerTK mRNA, and IAV-NP RNA levels in the lungs of mice challenged with IAV PR8 or IAV WSN for the indicated time points. Representative data from three independent experiments are shown. IAV-NP, IAV nucleoprotein; MerTK, myeloid-epithelial-reproductive tyrosine kinase.