Genetic diversity of Megalocytivirus from cultured fish in Korea

Since the first outbreak of Megalocytivirus infection in cultured marine fish in the 1990s, the Red sea bream iridovirus (RSIV) subtype II and Turbot reddish body iridovirus (TRBIV) type Megalocytivirus have been prevalent in Korea. Based on the major capsid protein (MCP) genes, the RSIV subtype II, as the predominant genotype, was identified in marine and freshwater fish including thread-sail filefish (Stephanolepis cirrhifer), so-iuy mullet (Planiliza haematocheila), starry flounder (Platichthys stellatus), and golden mandarin fish (Siniperca scherzeri). Recently, a new genetic variant of RSIV type (subtype I and II), SB5-TY originating from sea bass (Lateolabrax japonicas), was identified by their sequence identity with the four ankyrin repeat domains of RSIV (401R, 424R, 534L, and 641L). This result corroborate the evidence that increased genotypic variation in RSIV-type megalocytiviruses has been detected.