DAO 48:27-36 (2001)  -  doi:10.3354/dao048027

Characterization of an iridovirus from the cultured pig frog Rana grylio with lethal syndrome

Qi-Ya Zhang1,*, Feng Xiao1, Zhen-Qiu Li1, Jian-Fang Gui1, Jinghe Mao2, V. Gregory Chinchar2

1State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China
2Department of Microbiology, University of Mississippi Medical Center, Jackson, Mississippi 39216, USA

ABSTRACT: Three virus isolates, RGV-9506, RGV-9807 and RGV-9808, were obtained from cultured pig frogs Rana grylio undergoing lethal infections. Previously, the first isolate, RGV-9506, was shown to be an iridovirus based on ultrastructural and morphological studies. In the present study, the original isolate, along with 2 recent ones, were more extensively characterized by experimental infection studies, histopathology, electron microscopy, serological reactivity, gel electrophoresis of viral polypeptides and DNA restriction fragments, PCR amplification, and nucleic acid sequence analysis of the major capsid protein (MCP) gene. The 3 isolates were shown to be identical to each other, and very similar to FV3, the type species of the genus Ranavirus (family Iridoviridae). These results suggest that RGV should be considered a strain of FV3, and indicate that FV3-like iridoviruses are capable of causing widespread, severe disease among cultured frogs.

KEY WORDS: Rana grylio · Iridovirus · FV3 · Ranavirus · Viral disease

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