Quasi-immune response of Fenneropenaeus chinensis to WSSV and its verification

Abstract

In order to explore the quasi-immune response of Fenneropenaeus chinensis,healthy shrimps were vac-cinated with inactivated white spot syndrome virus(WSSV).WSSV was inactivated using varying doses of γ-ray irradiation.After 20 days of continuous feeding with inactivated WSSV,the surviving shrimps were exposed to active WSSV to test their survival rates.It was shown that over 216 hours,the survival rates attributable to IE-5 kGy,IE-10 kGy,IE-15 kGy and IE-20 kGy were 45.5%,54.2%,68%,and 65.4%,respectively;the mean WSSV loads of the surviving shrimps were(14.0±11.9),(14.1±4.3),(24.5±15.0) and(15.1±7.8) copies/ng DNA,com-pared with that of dead shrimps of(2.1±2.0)×105,(5.2±4.4)×105,(3.8±4.4)×105 and(6.2±7.7)×105 copies/ng DNA,respectively.Within the positive control group,the survival rate was 20%,and the mean WSSV copies of surviv-ing and dead shrimps were(24.7±7.4) and(5.8±6.9)×105 copies/ng DNA,respectively.It is suggested that the presence of a quasi-immune response system in F.chinensis is possible,and exposure to WSSV inactivated by γ-ray irradiation can improve the anti-virus resistance of the shrimps.These data show that WSSV can be pre-vented by vaccination,thereby providing data references for developing a healthy culture system for F.chinensis.