The genetic engineering research on the expression system of tussah NPV vector began in 1985. After years of efforts, the NPV polyhedral protein gene of Tussah was cloned, and the DNA sequence was analyzed, and the transcription start site of the gene was determined, and the transfer expression vector was constructed. At the same time, the spermary cell line of silkworm chrysalis sensitive to tussah NPV was established. 1992 successfully realized the expression of foreign genes in insect cells and tussah pupa, and initially established the expression system of tussah NPV vector. In the same year, he applied for the national invention patent, and obtained the patent authorization from the State Patent Office on 1997 (patent number 92 103655.8). The researchers analyzed and identified the main components of antibacterial active substances of tussah pupa, including antibacterial peptides A, B, D, lysozyme and coagulin. These protein were isolated and purified and their properties were analyzed. The relationship between antibacterial active substances and tussah varieties was clarified, which provided theoretical basis for tussah disease-resistant breeding.
Jiuru Tianbao oral liquid is made from female silkworm moth, which is used to treat senile prostatic hypertrophy and female climacteric syndrome. The above two products have been successfully transferred to Hainan Xin 'an Bioengineering Pharmaceutical Co., Ltd. and achieved gratifying economic benefits.
After culture and screening, the silkworm testis cell line which can be continuously subcultured has been stably passed to nearly one hundred generations. The experiment of infected cells with ApNPV showed that about 60% of the passaged cells could be infected by ApNPV. Further transfection with ApNPV-DNA was also successful. The establishment of silkworm sperm cell line is the first report at home and abroad. Insect antimicrobial peptides have strong antibacterial, antiviral and immune functions. Commonly used as in vitro bactericide, used in plant transgenic antibacterial breeding. In order to meet this demand, according to the sequence of insect antimicrobial peptide B gene, the insect antimicrobial peptide B gene was synthesized and cloned by artificial chemical synthesis, which laid the foundation for the next research.