IMMUNITY RESPONSE OF TRANSGENIC TIGER SHRIMP F1 AGAINST WHITE SPOT SYNDROM VIRUS (WSSV)

Transgenic technology of tiger shrimp Peneus monodon has been applied in order to produce a superior strain of tiger shrimp resistant to white spot syndrome virus (WSSV). Gene antivirus isolated form resistant tiger shrimp (survivor) was successfully transferred to the embryo in producing tiger shrimp founder (F0). In 2015, the breeding of founder (F0) transgenic tiger shrimp has been conducted to produce F1 population resistant WSSV. Gene antivirus insertion has been confirmed to the larvae by PCR technique.  This present study aimed to evaluate the immunity response of transgenic tiger shrimp F1 against WSSV by challenge test.

A challenge test was performed to the transgenic shrimp F1 and non-transgenic shrimp as a control treatment. The virus was collected from infected white spot diseases tiger shrimp, prior to be injected to the shrimp by intra-muscular method in dosage of 100 µL (based on the LC-50). The transgenic and non-transgenic shrimp with size, weight of 7.93±1.49 g and a total length of 9.15±0.58 cm was stocked at 5 shrimp/16 L aquarium, completed with aeration. Each treatment consisted of three replications. Survival rate (SR) was observed at 1, 2, 3, 4, and 5 day after challenge, and immune responses such as total haemocyte count (THC), haemocyte differentiation (HD), pro-phenoloxidace (pro-PO) activity, and RNA concentration were observed at 1, 3, and 5 day after challenge from the shrimp haemolymph. Data of SR was analyzed by t-student test, and immune responses were descriptively explained.

After 5 days of challenged with WSSV, the transgenic shrimp exhibited higher (P<0.05) resistance to the WSSV infection (52.0% survived) as compared to the control shrimp (8.0% survived) or equivalent with RPS (relative percentage survival) of 47.82%. The mortality of non-transgenic shrimp was sharply occurred at day-2 and continued until the end of study (Figure 1). The immune responses (THC, granular cell, pro-PO and RNA concentration) of transgenic shrimp showed higher value than the non-transgenic shrimp (Table 1).