Jian-mei Liu

Anti-oxidation and immune responses in mice upon exposure to manganese superoxide dismutase expressed in silkworm larvae, Bombyx mori L.

With manganese superoxide dismutase expressed in silkworm larvae, Bomby mori L, we investigate the effects of silkworm larvae powder containing SOD on the antioxidation and the immune system of mouse. The contents of MDA both in mice plasma or liver organ treated with silkworm larvae powder containing manganese superoxide dismutase were reduced compare to control. The superoxide dismutase (SOD) and glutathione peroxidase (GSH‐Px) activities both in plasma or liver organ of the treated mice were significantly higher than that of both control and bromobenzene treated mice (group‐BM), suggesting the silkworm larvae powder containing SOD play a positive role in anti‐oxidation in mice. This experiment was also designed to investigate the effects of silkworm larvae powder containing SOD on the immune system of mouse, focused on hemolysin response, hemagglutination against SRBC and the activity of natural killer (NK) cells. All treated mice showed significant increase in hemolysin response to SRBC and demonstrated an activation of NK cell function by the SOD‐contained silkworm larvae powder, which suggest a promotion in humoral immunity. The results suggested the SOD expressed in silkworm maybe have potential application in medicine.

Proteomic identification of the silkworm (Bombyx mori L) prothoracic glands during the fifth instar stage.

Although the ecdysteroid of the silkworm had been studied for decades, the proteome of the prothoracic gland, the primary source of ecdysteroid hormones, has not been studied previously. In the present paper, we utilized a proteomic approach to investigate the fifth instar prothoracic gland during the growth and development of the silkworm, Bombyx mori L. The two-dimensional electrophoresis results showed that the majority of proteins were acidic proteins, especially concentrated in the area of 25-65 kDa, with pI values of between 4 and 7, and the difference was not distinct. When compared with Qiufeng (Japanese strain), the interspecific distinction was larger than the intraspecific distinction, and 19 particular spots, excized from the third, fifth and ninth days of p50 (Chinese strain) and Qiufeng were subjected to MALDI-TOF-MS (matrix-assisted laser-desorption ionization-time-of-flight MS) analysis. We sorted them into seven catagories: energetics and/or metabolism, storage proteins, protection, lipid metabolism, signal transduction, cell function and unknown function proteins. Of these proteins, arginine methyltransferase is discussed as playing an important role in regulating the activation of ecdysteroidogenesis via transcription or translation.

Improvement of recombinant baculovirus infection efficiency to express manganese superoxide dismutase in silkworm larvae through dual promoters of Pph and Pp10

The silkworm, Bombyx mori, has been used as an important bioreactor for the production of recombinant proteins through baculovirus expression system (BES). There are several problems which will probably be the bottleneck for practical and industrial utilization of silkworm bioreactor. Traditionally, the recombinant virus should infect the larvae through individual dorsal injection by a syringe. This is a time- and labor-consuming procedure. This drawback has become a bottleneck for practical and industrial utilization of baculovirus expression system in the silkworm bioreactor. In this paper, we constructed a dual expression baculovirus to express the renovated polyhedron and target manganese superoxide dismutase (SOD) gene under P10 and polyhedron promoters, respectively, through oral infection. The results showed that the direct injection of recombinant rBacmid/BmNPV/SOD DNA with cellfectin reagent infected the silkworm larvae partially. When next batches of larvae were fed orally with hemolymph, which was collected from first batch of injected and infected larvae, the obvious symptom of infection was found and high target SOD was expressed. These results imply it is feasible to express target genes through combination of recombinant bacmid DNA injection and oral feeding by a dual expression bacmid baculovirus.

Application of proteomic technology in silkworm research

Abstract From structural genome to functional one, the proteomic research has been an important content in the post-genome times. This paper presents the concept of proteome, and introduces its research technology and status in silkworm research.