自美洲大口鱸分離出病毒之生化及免疫特性

Abstract

摘要 由體表潰爛，肝臟腫大壞死等病徵的美洲大口鱸魚(Micropterus salmoides (Lacpede), Largemouth Bass）所分離出之病毒Pereh virus(PV)，可在多種魚類細胞株中複製增殖，最適生長溫度為18?22℃。此病毒是一不具外套膜的單層蛋白質鞘二十面體顆粒，大小約為55nm。由代謝抑制物FUDR, Actinomycin D試驗，RNase A測驗，顯示此病毒遺傳物質為雙股核醣核酸。此核酸經電泳分析知其為二段的核醣核酸，大小為2.2×106, 2.0×106 daltons。利用放射性標示細胞內病毒蛋白質之合成，可知在早期有4種蛋白質α,β1,γ1，γ2，後期則β1會降解成β2,β3,此和Birnaviridae之IPNV特性相似。PV與IPNV的Ab, SP, VR-299及EVE在核酸及蛋白質圖型上之分析比較，顯示PV近似EVE。PV與Ab, SP, VR-299及EVE之兔子抗血清作中和試驗，其中和指數以及與EVE單株抗體作用之結果，都顯示PV與EVE相近。

Abstract Perch virus (PV) was isolated from diseased Largemouth Bass (Micropterus salmoides (Lacpede)) which showed ulcer lesion over the body and necrosis of the liver. PV can grow in tissue culture in a variety of established fish cell lines at an optimal temperature of 18?22℃. Electronic microscopic observation of purified virus revealed naked icosahedrons and with a diameter approximately 55nm. The studies of FUDR, actinomycin D, and RNase A treatment of PV indicated that the viral genome is double stranded RNA which can be separated into two segments by polyacrylamide gel electrophoresis. They are 2.2×106, 2.0×106 daltons. By labeling UV-irradiated infected cells with 35S-methionine, four virus specific proteins,α,β1,γ1,γ2，synthesized in the early stage of infection. In the late stage, β1 would be cleaved via β2 intermediate to generate β3. These characteristics are very similar to those of Birnaviridae IPNV. By a comparison of the analysis of RNA and protein pattern of different IPNV-like virus, the neutralization test of PV against different IPNV antiserum, and the immunoassay of PV with EVE monoclonal antibodies, PV was found to be very closely related to EVE.