Fig 1. AT-rich regions of the ASFV genome induce IFN-β.

(A) Comparison of the total AT-content of the ASFV genome with genomes of HSV-1, EBV and VZV. (B) The content and distribution of AT-rich regions in the genomes of ASFV were compared with those in the genomes of HSV-1 and VZV using the EMBOSS Isochore algorithm. Regions with AT content more than 70% are shown. (C) Effects of knockdown of cGAS or RIG-I on IFNB1 transcription induced by ASFV or HSV-1 infection. PAMs (1×10⁶) were transfected with the indicated siRNA (final concentration, 25 nM each) for 48 hours, and then the cells were infected with ASFV or HSV-1 (MOI = 0.1) for 4 hours. The mRNA levels of IFNB1, cGAS, and RIG-I were analyzed by qPCR. (D) The AT-rich DNA of the ASFV genome activates the IFN-β promoter. HEK293T (1×10⁵) were transfected with the IFN-β promoter luciferase plasmid. Twenty-four hours later, these cells were stimulated with transfected dsDNA as indicated (1 μg/ml) for 10 hours before luciferase assays were performed. ASFV-AT and ASFV-GC are short for ASFV/DNA-AT and ASFV/DNA-GC respectively. (E) qPCR analysis of mRNA levels of the indicated genes stimulated by transfected dsDNA (1 μg/ml) for 6 hours in HEK293T and PK-15 cells.