Premium
Macrobrachium rosenbergii nodavirus infection in M. rosenbergii (de Man) with white tail disease cultured in Taiwan
Author(s) -
Wang C S,
Chang J S,
Wen C M,
Shih H H,
Chen S N
Publication year - 2008
Publication title -
journal of fish diseases
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.819
H-Index - 85
eISSN - 1365-2761
pISSN - 0140-7775
DOI - 10.1111/j.1365-2761.2008.00921.x
Subject(s) - biology , virology , rna , microbiology and biotechnology , amplicon , primer (cosmetics) , virus , macrobrachium rosenbergii , capsid , polymerase chain reaction , complementary dna , gene , genetics , prawn , fishery , chemistry , organic chemistry
White tail disease (WTD) is a serious problem in Macrobrachium rosenbergii hatcheries and nursery ponds in Asia. The causative agents have been identified as M. rosenbergii nodavirus ( Mr NV) and its associated extra small virus. This is the first report demonstrating Mr NV virus in M. rosenbergii displaying WTD signs in Taiwan by reverse transcriptase‐polymerase chain reaction (RT‐PCR). Amplified fragments of 850 and 425 bp for RNA‐1 and RNA‐2 of Mr NV, respectively, were obtained by RT‐PCR. RT‐PCR products of about 850 and 1121 bp for RNA‐1 and RNA‐2 of Mr NV were also obtained using different primer pairs. The amplicons were individually cloned into pGEM‐T vector and sequenced. Using this recombinant plasmid of Mr NV RNA‐2 as DNA template, the non‐radioactive DNA probes were prepared by PCR amplification with DIG–11‐dUTP. The probes were used to successfully detect Mr NV infection in the striated muscle tissues of WTD‐diseased prawns using in situ hybridization. The 1121 bp genomic fragment of RNA‐2 of Mr NV consisted of a unique open reading frame with 1116 nucleotides, and it encoded a structural protein with 371 amino acids. The nucleotide sequence of the partial genome of Mr NV RNA‐2 revealed a 97% identity with an Indian isolate. A phylogenetic tree constructed using the nucleotide sequence of the viral capsid gene from insect and fish nodaviruses revealed that the Mr NV Taiwan isolate could be interpreted as a new genus within the family Nodaviridae . However, its position showed more affinity with Alphanodavirus than with Betanodavirus . The study confirmed the presence of Mr NV infection in freshwater prawns cultured in Taiwan suffering from WTD.