Control of VNN in Striped Jack : Selection of Spawners Based on the Detection of SJNNV Gene by Polymerase Chain Reaction (PCR)

シマアジVNNの予防法 : PCR法を用いたSJNNV遺伝子の検出による産卵親魚の選別

Mushiake Keiichi

Nishizawa Toyohiko

Nakai Toshihiro

Furusawa Iwao

Muroga Kiyokuni

魚病研究

Fish Pathology

PCR法によるシマアジ親魚(生殖巣)からのウイルス性神経壊死症(VNN)原因ウイルス(SJNNV)遺伝子の検出結果と仔魚でのVNN発生との関係を検討した。その結果, VNNはウイルス陰性親魚群からの仔魚には発生せず, ウイルス陽性魚を含む親魚群の仔魚に発生した。また後者の親魚群からウイルス陽性魚を除去して産卵させて得た仔魚にはVNNは発生しなかった。従って, PCR法によるウイルス遺伝子の検出はVNN防除のための親魚選別に有効であると考えられた。

A preventive trial of viral nervous necrosis (VNN) in larval striped jack Pseudocaraux dentex was made by selecting virus-free spawners based on the detection of the causative virus (SJNNV) gene by polymerase chain reaction (PCR) method. PCR detection of SJNNV gene from fish was done by amplifying the target sequence (T4: 426 bp) of the coat protein gene (RNA2). Four spawner groups, each consisting of 12 to 16 fish, were examined for the presence of SJNNV in their gonads just before spawning at one month intervals. Their offsprings (eggs and larvae) were subjected to rearing experiments to observe the occurrence of VNN.

The SJNNV gene was detected from some spawners of these groups at the late spawnings. VNN occurred in larvae from spawner groups including SJNNV gene-positive fish, but not in larvae obtained from spawner groups which consisted of SJNNV gene-negative fish. These results suggest that the selection of striped jack spawners based on the detection of SJNNV gene from gonads by PCR just before spawning is efficacious for the prevention of vertical transmission of SJNNV in seed production.

Fishing industry. Fisheries [ 660 ]

eng

日本魚病学会

[ISSN] 0388-788X

[NCID] AN00063165