Characterization and partial cloning of the genomic DNA of a baculovirus from Penaeus japonicus (PjNOB = BMNV)

Abstract

Many particles of a non-occluded baculovirus with a membrane 70 × 330 nm in size were observed in the nuclei of the mid-gut glands of larval Kuruma shrimp ( Penaeus japonicus) with mid-gut necrosis using an electron microscope. Nucleotides of the baculovirus were isolated from the diseased larvae in the presence of Triton X-100. The nucleocapsid was a bacilliform virion, approximately 50 nm in width and 260 nm in length. From the purified preparations of nucleocapsids of the virus, two major proteins with molecular weights of 35 and 14 kDa were identified by SDS-polyacrylamide gel electrophoretic analysis. The viral genomic DNA extracted from the nucleocapsids was digested with BamHI and Sau3AI, but not with EcoRI, PstI, XhoI and SalI. The molecular weight of the DNA was estimated to be approximately 85.1 × 10 6 from the agarose gel electrophoretic pattern of the BamHI fragments. A part of the BamHI fragments was cloned, labeled with 32P-CTP and used for Southern blot analysis as a probe. The fragment hybridized to DNA isolated from the diseased larvae, but not to DNA isolated from healthy larvae.