FIG 1.

Transcriptomic identification of HSP70 as a key player in GCRV infection. (A) Numbers of genes with significant differences in transcriptomic data (NCBI accession number PRJNA759556) in different tissues from GCRV-infected grass carp. TG, total gene number; HN, HSP gene number; NG, downregulated HSP genes or nonsignificant HSP genes; UP, upregulated HSP genes. (B) Heat map analysis of transcriptomic data (NCBI accession number PRJNA759556) for HSP genes in spleen and head kidney tissues from GCRV-infected grass carp. (C) Volcano plot analysis of all genes differentially regulated from transcriptomic data (NCBI accession number PRJNA600033) in spleen tissue from grass carp infected with GCRV on the 5th day. (D) Heat map analysis of transcriptomic data for the vast majority of HSP genes from panel C. (E to H) Healthy grass carp of about 8 to 10 cm were intraperitoneally infected with GCRV. The gill and spleen tissues at 0, 1, 5, 7, and 10 days were harvested by TRIzol to analyze the replication of GCRV (E and F) and the expression of Hsp70 genes (G and H) by RT-PCR. (I to K) CIK cells were infected with GCRV (MOI ≈ 5) at 28°C and harvested by TRIzol at different time points (1, 3, 6, 9, 18, and 24 h) to analyze viral genome replication (I), HSP70 transcription (J), and the protein level of VP7 and HSP70 (K) by RT-PCR or Western blot approaches.