Transcriptional programs of infectious spleen and kidney necrosis virus (ISKNV) in vitro and in vivo.

Infectious spleen and kidney necrosis virus (ISKNV), causing serious infectious diseases to marine and freshwater fishes, is the type species of the genus Megalocytivirus, family Iridoviridae. In this study, the transcriptional programs of ISKNV in vitro (MFF-1 cells) and in vivo (spleens from mandarin fish) were investigated using real-time PCR. Transcription of all the putative open reading frames (ORFs) of ISKNV was verified. The temporal expression patterns of ISKNV ORFs in vitro and in vivo, including peak expression times (PETs) and relative maximal expression levels, were determined and compared. The K-means clustering with Spearman rank correlation was generated in heat maps constructed based on ISKNV ORF expression profiles in vivo and in vitro. The current study may provide a global picture of ISKNV infection at the transcription level and help better understand the molecular pathogenic mechanism of megalocytiviruses.