Identification of the main target organs of white spot syndromevirus(WSSV)in digest track of Litopenaeus vannamei

White spot syndrome virus(WSSV)isone of the most lethal pathogens inculturedshrimp.In this study,we mimicked the matural infective process of WSSV to Litopenaeus tamnamei by feeding the shimp with the muscleof WSSV infected Procambarus clarkia.The viral loads in the digest organs of imfected shimp were determined byreal-time quantitativePCR.The results showed that from 12 h to 24 h post-infection,viral DNA copies inthe stom-ach increased over 100 times,while therewas only a three-fold increase in esophagus and a fivefold increaseinmidgut.Further investigation with scanning electromie microscopy indicated that WSSV had a much higher affinityto the inner surface of stomach than to esophagus and midgut.Moreover,in contrast to the intact virions,WSSVnuclear capsids could not attach to any of the digestive organ analyzed in this study.Therefore,we conclude thatstomach is the main targetorgan of WSSVin the digest tract of penaeid shrimp,and theenvelop proteins are essen-tial for the interaction between WSSV and the host cells.