Identification Of Pathogeny Related Early Proteins Of White Spot Syndrome Virus And Functional Research Of The Homologous Repeat Regions Within The Genome

Shrimp White Spot Syndrome Virus (WSSV), which has also deen referred to as White Spot Bacilliform Virus (WSBV), is a major pathogen of cultivated shrimp but its host range includes a large number of crustaceans. This paper is concerned on the possible pathogen related gene, expecially on the viral early gene products and DNA-specific binding proteins, for studying the infection machenism of WSSV on functional proteomics level.In this thesis, three main works are included. (1) Using Anemia franciscana as experimental animals, we briefly expatiate on the host wideness of WSSV. (2) The structure and function of two infection- and pathogen-related proteins of WSSV, an unique viral collagen and a highly conserved viral thymidylate synthase, was identified and characterized. (3) Isolation and identification of DNA-specific binding proteins of WSSV and the modification and regulation of these cofactors in process of viral transcription and translation by using a combination of DNA-affinity chromatography, SDS-PAGE and mass spectrographic analysis.The results we obtained in this thesis showed, D As a member of crustaceans, Artemia fransicana was predicted to be passively non-infectious carrier of WSSV. In Artemia, WSSV was not proliferation and can be transmited from nauplii to adult. WSSV was removed during the hatching of the reproductive cysts and the offspring Artemia was WSSV PCR-negative. D As the largest DNA virus which sequence has been completely sequenced, WSSV-clp and ts gene was transcribed at the early stage of infection. WSSV-CLP was an envelope protein and located between the double-layer membranes of WSSV and can form a network structure under transmission electron microscopy. WSSV-CLP was the first envelope protein that discovered to beglycosylated by using the treatment of N-glycosylationase F. WSSV-te encodes a highly conserved protein, and the recombination TS maintained substrate-specific binding activity. Without obviously polyadenylation signal [poly(A)], result of 3'-RACE indicated that ts was transcribed during infection and the mRNA was found contain a poly A at the 3'terminer. D Through the recombination of improved affinity chromatography, SDS-PAGE and gel mobility shift assay (GMSA), the ///rs-specific binding protein comples were isolated and purified. This protein fraction was thought to be involved in the gene replication of WSSV and interaction with host proteins.The results suggested that WSSV-CLP was a WSSV envelope protein that is N-glycosylated. It may play important roles in infection of WSSV as other glycoproteins found in the envelope of Baculoviridae. Together with a seriers of early genes, WSSV-TS constructed a de novo dTMP synthses system, which plays important roles in viral DNA replication. The hrrs-specific binding protein complex showed us important information on the replication of WSSV DNA. This suggest that when the virus enters the host cells, viral early genes is expressed and form complexes in the immediately early stage of infection with the regulation of host proteins which make it possible to consider this as the main causes for the rapid death of infected shrimp. Results in these investigations lead us directions for the prevention and for the therapy of WSSV.