Cloning, Expression Of Envelope Protein Gene Vp28 Of Shrimp White Spot Syndrome Virus And Commone Carp Growth Hormone Gene GH In Escherichia .Coli

In 1993, a disastrous infection in penaeid shrimp broke out in China, which induced by white spot syndrome virus (WSSV). It causes a high mortality of up to 90-100% in shrimps within 3-7days of infection. Outbreaks also occasionally took place in South America. Europe and Australia. It resulted in heavy economic losses for the world. Despite all the research efforts, up to date no effective measures or medicaments are available to prevent the spreading of WSSV. WSSV has a double-stranded DNA genome with a size of 305, 107bp. The viral particle consists of at least five major proteins with estimated sizes of 28kDa(VP28), 26kDa(VP26), 24kDa(VP24), 19kDa(VP19), and 15 kDa(VP15). VP28 and VP19 are associated with the virion envelope and VP26, VP24, and VP15 with the nucleocapsid.The envelope of virus plays a key role in the process of viral infection and be somehowlinked to be the virulence of the virus itself. WSSV has two important envelopes vp28 and vp19. And vp28 has been proved that it is located in the spikes of the WSSV envelope and this protein may thus be involved in the systemic infection of WSSV in shrimp. At present, the experiments demonstrate that recombinant vp28 in Ecoli has improved immunity ability to WSSV infection.The growth hormone of fish is a kind of single-subunit protein secreted by the pituitary of fish .It can increase the expression of protein, degradation of lipid and serves an important part in growth of fish. The expertments provided the recombinant fish growth hormone can accelerate growth and advance immunity ability of young seashell and Chinese shrimp.Total RNA was isolated from common carp pituitary. The cDNA encoding carp mature growth hormone (GH) peptide was amplified by reverse transcription polymerase chain reaction (RT-PCR) method using isolated total RNA as template. The DNA sequence of vp28 was amplified by PCR using the plasmid with vp28 as template.We constructed high efficient expression of E.coli BL21(DE3)-pET-vp28 and E.coli BL21(DE3)-pET-GH.We expressed the protein of GH and vp28 in Ecoli in order to utilize the expression products' function of improving the immunity ability of shrimp, especially immunity ability to WSSV infection. We hope to apply the expression products to aquatic product breeding .