Studies on Virogenesis and Cytopathology of Penaeus monodon Baculovirus(MBV) in the Giant Tiger Prawn (Penaeus monodon) and the Red Tail Prawn (Penaeus penicillatus)

The cytopathology and virogenesis of monodon-type baculovirus (MBV) in the hepatopancreatic cells of the cultured shrimps, giant tiger prawn (Penaeus monodon) and red tail prawn (P.penicillatus), were investigated. In the hepatopancreatocytes of infected giant tiger prawns, F, B, R and M cells were found to be susceptible to MBV. Detailed virogenesis of MBV including formation of nucleic acid, capsid substance, envelopment and formation of occlusion bodies in hepatopancreatocytes of the giant tiger prawn was also noted. The main cytopathogenic changes accompanying MBV infection observed on membranes of the hepatopancreatocytes, and nuclear hypertrophy were due to virogenesis and polyhedrin formation.Virus particles and occlusion bodies released from lysed cells entered the intestinal tract via the hepatopancreatic lumen. In addition to the giant tiger prawn, the red tail prawn, P.penicillatus, were also found to be infected by MBV. This is a new reported host for MBV. Average size of the viron and diameter of the nucleocapsid observed in red tail prawn was signilcantly smaller than those present in giant tiger prawn. However, no significant differences were obtained when the length of nucleocapsids and size of the polyhedrin subunits were compared.