Dynamic Distribution of Shrimp White spot syndrome virus(WSSV)Qingdao Strain in Crawfishes by Dot Hybridization
Abstract: A fragment sized 40Obp ofWhite spot syndrome virus(WSSV,formerly designatedNOSV), recovered from recombinant plasmid pAFD.was labeled with Digoxigenin as a probe to detect dynamic distribution of WSSV within 120h and 72h in crawfishes(Cambarus procla ii)inoculated WSSV by oral taking and injection respectively.Stomach epithelium, intestine epithelium, heart, gill, haemolymph,muscle,hepatopancreas-hypoderm ,connective tNsue and ovary of infected crawfishes were examined for W SSV In both groups.W SSV was first detected in heamolymph at 12h P.i.and then disappeared Again it was detected at 96h P.i.only in oral infection group and maintained till 120h P.i.,but it didn’t appear at 72h P.i.in injection group.WSSV in heart.muscle was detected at 36h P i in oral infection group and 24h P.i in injection group respectively.and then increased generally.In addition,W SSV in intestine epithelium,con ective tissue,ovary of oral infection group and intestine epithelium.hypoderm,ovary of injection group could also be detected.In dead crawfish— es after l20h and 72h P i in two groups.WSSV could be detected in all the examined tissues and it demonstrated that systemic infection occurred in the animales.The tissue containing more amounts of W SSV was hypoderm in oral infection group,while intestine epithelium.gil1.hypoderm,ovary in in· jection infection group It deduced that W SSV first appears in haemolymph and then goes into hean, muscle and other tissues and proliferates in them.Once again,W SSV is released into heamolymph re— sulting in systemic infection till crawfishes’death