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DAO 39:169-176 (2000)

Monodon baculovirus from Australia: ultrastructural observations

J. E. Vickers1,2,*, R. Webb1,3, P. R. Young1,4

1Department of Microbiology, 2Department of Parasitology and 3Centre for Microscopy and Microanalysis, University of Queensland, Brisbane, Queensland 4072, Australia
4Sir Albert Sakzewski Virus Research Centre, Royal Children's Hospital, Herston Rd, Brisbane, Queensland 4006, AustraliaE-mail:

ABSTRACT:    The cytopathology, virogenesis and replication of monodon baculovirus (MBV) in Penaeus monodon from Australia are described. Electron-dense unenveloped nucleocapsids, not previously described for MBV, are shown in the cytoplasm and attached to the nuclear envelope of infected hepatopancreatocytes. These nucleocapsids comprise a missing link in the published literature on the replication cycle of MBV by providing evidence for the means by which the viral genome travels from the plasma membrane of the hepatopancreatocyte to the nucleus. Features similar to those of MBV from other areas, but not previously reported for MBV from Australia include empty capsids attached to the nuclear pore, central filaments in developing capsids, capsids partly filled with nucleic acid, and filaments in subapical envelope expansions. A model for virogenesis and replication is illustrated which takes into account the new observations as well as previously described ultrastructural characteristics of the developing viral particle.

DAO 40:93-99 (2000)

Diagnosis of Penaeus monodon-type baculovirus by PCR and by ELISA of occlusion bodies

Y. L. Hsu1,*, K. H. Wang2, Y. H. Yang1, M. C. Tung3, C. H. Hu2, C. F. Lo4, C. H. Wang5, T. Hsu2,*

1Institute of Zoology, Academia Sinica, Taipei, Taiwan, ROC
2Institute of Biotechnology, National Taiwan Ocean University, Taiwan, ROC
3Department of Veterinary Medicine, National Ping-Tung Polytechnic Institute, T ROC
4Department of Zoology and 5Department of Entomology, National Taiwan University, Taiwan, ROC.  E-mail:

ABSTRACT:     The black tiger prawn Penaeus monodon is a valuable aquaculture product in Taiwan. Two specific diagnostic methods were established for P. monodon-type baculovirus, one using polymerase chain reaction (PCR) technology and the other enzyme-linked immunosorbent assay (ELISA) technology. Monodon-type baculovirus (MBV) was purified by sucrose gradient centrifugation from occlusion bodies of MBV-infected postlarvae of P. monodon. MBV DNA was subsequently purified from the occlusion bodies and its presence was confirmed by PCR using primers of the polyhedrin gene. Based on conserved sequences of the DNA polymerase genes of Autographa californica nuclear polyhedrosis virus (AcMNPV) and Lymantria dispar nuclear polyhedrosis virus (LdMNPV), primers were designed and synthesized to yield a 714 bp PCR fragment from MBV. However, the sequence of this fragment revealed low homology with that of LdMNPV and AcMNPV. From the DNA sequence of this fragment, a second set of primers was designed, and using these primers, a 511 bp DNA fragment was amplified only when MBV DNA was the template. DNA templates from AcMNPV, white spot syndrome diseased shrimp, or PMO cells (a cell line derived from the Oka organ of Penaeus monodon) did not give any amplified DNA fragment. Therefore, this primer pair was specific for the diagnosis of MBV. By using intraspleenic immunization of rabbits with purified MBV occlusion bodies, a polyclonal rabbit antiserum against MBV was obtained. This antiserum could detect nanogram levels of MBV, but did not cross react with white spot syndrome virus (WSSV), homogenates of PMO cells, postlarvae, hepatopancreatic tissue or intestinal tissue of black tiger prawns by competitive ELISA. This sensitive method could detect MBV even in tissue homogenates.