title: A new marine megalocytivirus from spotted knifejaw, Oplegnathus punctatus, and its pathogenicity to freshwater mandarinfish, Siniperca chuatsi.
abstract: Megalocytivirus is a newly defined piscine iridovirus and has been shown to be an important causative agent of viral diseases in fish. Here, a new megalocytivirus strain, designated SKIV-ZJ07, was isolated from spotted knifejaw (Oplegnathus punctatus) using a mandarinfish fry cell line (MFF-1). Phylogenetic analysis of the major capsid protein and ATPase genes showed that SKIV-ZJ07 was most similar to the orange-spotted grouper iridovirus (OSGIV) from China and a U1 strain red sea bream iridovirus (RSIV-U1) from Japan. SKIV-ZJ07 was purified and the major viral proteins were identified using one-dimensional gel electrophoresis mass spectrometry (1-DE-MS) analysis. Twenty proteins were found to match proteins derived from rock sea bream iridovirus (RBIV), OSGIV and infectious spleen and kidney necrosis virus (ISKNV). Among these, 19 proteins had not been previously identified as virion-associated proteins in megalocytivirus. Challenge tests showed that SKIV-ZJ07 was highly virulent in mandarinfish. Infected fish displayed typical histopathological symptoms of ISKNV-infected fish and died, indicating that the mandarinfish is an ideal model for further study of megalocytivirus-host interactions, molecular mechanisms of viral infection and pathogenesis. Interestingly, large numbers of regular paracrystalline SKIV-ZJ07 virion arrays were observed in both SKIV-infected MFF-1 cells and mandarinfish tissues by transmission electron microscopy (TEM), which is unusual for megalocytivirus under artificial infection conditions. Taken together, the results presented here provide new insight into the pathology of megalocytivirus infection.
authors.affiliation: State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen (Zhongshan) University, Guangzhou 510275, People's Republic of China.
authors.forename: Chuanfu
authors.initials: C
authors.lastname: Dong
authors.forename: Shaoping
authors.initials: S
authors.lastname: Weng
authors.forename: Yongwen
authors.initials: Y
authors.lastname: Luo
authors.forename: Mingming
authors.initials: M
authors.lastname: Huang
authors.forename: Huashui
authors.initials: H
authors.lastname: Ai
authors.forename: Zhixin
authors.initials: Z
authors.lastname: Yin
authors.forename: Jianguo
authors.initials: J
authors.lastname: He
mesh_terms: D000251:Adenosine Triphosphatases / Q000235:genetics; D000818:Animals; D036022:Capsid Proteins / Q000235:genetics; D002460:Cell Line; D016000:Cluster Analysis; D004266:DNA Virus Infections / Q000662:veterinary* / Q000821:virology; D004279:DNA, Viral / Q000737:chemistry / Q000235:genetics; D004591:Electrophoresis, Polyacrylamide Gel; D007497:Iridoviridae / Q000737:chemistry / Q000145:classification* / Q000302:isolation & purification* / Q000472:pathogenicity; D013058:Mass Spectrometry; D046529:Microscopy, Electron, Transmission; D008969:Molecular Sequence Data; D010473:Perciformes / Q000821:virology*; D010802:Phylogeny; D020543:Proteome / Q000032:analysis; D017422:Sequence Analysis, DNA; D017385:Sequence Homology; D014764:Viral Proteins / Q000032:analysis / Q000235:genetics; D014771:Virion / Q000648:ultrastructure; D014774:Virulence
chemical_list: D036022:Capsid Proteins; D004279:DNA, Viral; D020543:Proteome; D014764:Viral Proteins; D000251:Adenosine Triphosphatases