• KSBB Journal
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• v.10 no.3
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• pp.317-322
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• 1995

Insect cells were grown and infected with baculovirus for the production of recombinant protein. Later infection gave the lower expression of recombinant protein. This indicates that the expression rate is lower at higher cell concentration. This phenomena provides a well-posed optimization problem with respect to the infection time. The optimal infection time was experimentally shown to exist for the maximum productivity of recombinant protein. Also, the expression increased with the addition of 5% silkworm hemolymph. This is considered to be due to the increase of intracellular viruses and the longevity of viable cells after the infection. The production of ${\beta}$-galaclosidase increased about ten-fold with the addition of yeastolate and silkworm hemolymph for high cell density and high expression, respectively.

• Journal of Sericultural and Entomological Science
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• v.2
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• pp.33-39
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• 1962

The results for the investigation of the various aromatic plants applied diets on silkworm raising from spring to autumn crops are found as followings. 1. There was no difference between the chemical menthol solution (1.0%) enriched diet and the normal diet for silkworm physiology. Neither injury nor advantage was obtained from the investigation. 2. It was found that there was no danger to use the mulberry leaves as silkworm diet by planting Mentha arvensis L. in the vacansy of mulberry farm, and no worse effect was found by rubbing the leaves of Mentha arvensis L. to the surface of mulberry leaves before feeding to silkworm. 3. For the investigation due to Perilla Ocymoides var application in stead of menthol plant ascribed in Paragraph (2) was obtained the same result. 4. As a conclusion of the study, the plantation of the both aromatical plants with mulberry trees is harmless for silkworm growing even though farmers worry about these to plant together with mulberry tree on mulberry farm.

• The Korean Journal of Zoology
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• v.26 no.2
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• pp.83-93
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• 1983

Vitellogenin was purified from the haemolymph of female pupae during egg formation of Bombyx mori using DEAE-cellulose column and its quantitative change in various organs with age ws examined by electrophoresis and immunodiffusion. Vitellogenin is distributed in the haemolymph, fat body, and over the egg maturation and especially maintainsa constant level in the haemolymph until just before emergence, indicating that vitellogenin in released into the haemolymph at the same amount as it is taken up by oocytes during pupal period. Immunologically vitellogenin was confirmed to be in the fat body until 7 days after pupation and to undergo a drastic decline thereafter. Also, the interaction of anti-ovary proteins with haemolymph proteins showed at least 3 homogeneous proteins, indicating that other proteins as well as vitellogenin are involved in egg formation.

• Journal of Sericultural and Entomological Science
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• v.31 no.1
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• pp.37-44
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• 1989

The parasporal crystals of Bacillus thuringinsis subspecies kurstaki, dendrolimus, finitimus, aizawai and israelensis were compared by polyacrylamide electrophoresis, amino acid composition and immunological analysis. In the subspecies of kurstaki, dendrolimus, finitimus and aizawai, the molecular weights of main subusnits of crystal solubilized by alkaline solution were 1.3${\times}$105 and 6.5${\times}$104 while those of subsp. israelensis were 4${\times}$104 and 1,4${\times}$104. The degradation of lepidopteran toxic subspecies crystals by silkworm midgut protease showed 6.0-6.4${\times}$104 molecular weight and the pattern of degradation of subsp. israelensis crystals was similar to that of alkaline solution treatment. In the amino acid composition, aspartic acid in subsp. israelensis and glutiamic acid in the other four subspecies were the most abundant. The immunological characteristics of the crystals revealed that the antibody produced against the alkali-solubilized crystal protein of subsp. israelensis reacted with only its antigen, but the crystal antigens from the other four lepidopteran toxic subspecies did cross-react with each other as well as with their own homologous antisera.

• Journal of Sericultural and Entomological Science
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• v.52 no.1
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• pp.39-44
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• 2014

We isolated highly-expressed genes in the posterior silk glands of silkworm on a previously study, which one of these was identified as RNA binding protein-1 homologue (RBP-1) gene. In this study, we investigated gene expressional characteristics of the RBP-1 depending on silkworm development stages and several tissues of the larvae, respectively. Northern blot hybridization analysis showed that the RBP-1 gene was expressed high in larval and pupal periods, and highly expressed than endogenous internal control gene (BmA3) on all tested larval tissues. In addition, we isolated and analyzed a phage DNA having 1,660 bp-long promoter region of the RBP-1 gene from a genomic DNA library. To study the RBP-1 gene promoter activity, RBP-1 (-740/+ 30) was amplified by PCR and subcloned into a pGL3 basic vector to generate pGL-RBP1. A luciferase report vector carrying RBP-1 gene promoter (770 bp) was tested by luciferase assay in Sf9 cells. In the result, the RBP-1 gene promoter was more efficient than constitutive promoter (BmA3) by approximately ten percent.

• Journal of Sericultural and Entomological Science
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• v.51 no.2
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• pp.191-196
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• 2013

This study was aimed for development of a useful genes that has a transcript expressional specificity in the early embryonic stage of the silkworm, Bombyx mori. We constructed and analyzed a full-length cDNA library from silkworm's eggs which after a lapse of 2 ~ 6 hours post oviposit. A total 960 clones were randomly selected, and the 5' ends of the inserts were sequenced to generate 652 expressed sequence tags(EST). 334 unique ESTs were generated after the assembly of 652 ESTs. The annotation of 334 unique ESTs by BLAST search revealed that 156(47%) of the sequences represented known genes, whereas 178(53%) of the sequences has no matches in the database. Of the 156 known genes, the most abundant genes were heat shock protein hsp20.8 gene(12 times) and ubiqutin-like protein gene(11 times). The functional groups of these ESTs with matches in the database were constructed according to their putative molecular functions. Among thirteen functional categories, the largest groups were protein synthesis(9.6%) and cellular organization( 8.1%). Further defined studies on molecular functions and biological roles of their promoters will give us wellfined information and its application.

• Korean journal of applied entomology
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• v.35 no.1
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• pp.58-65
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• 1996

This experiment was carried out to evaluate the effect of sublethal doses of BPMC, etofenprox, and buprofezin on N. lugens. and its predator C. lividipennis. Buprofezin was found to be the most toxic to N. lugens and the most safe to C. lividipennis among the three insecticides, based on LD50 values. Selective toxicity index calculated by dividing LDSo value of C. lividipennis by that of N. lugens indicated that buprofezin was very safe to C. lividipennis, showing selective toxicity of 2703.3. Longevity and fecundity of N. lugens treated with LDIU and LDm of buprofezin and BPMC were not significantly different with those of untreated brown planthoppers. However, egg hatchability' of N. lugens was greatly reduced when treated with LDm of buprofezin, having the highest inhibition rate of 17.7%. Hatchability of eggs from insects treated with BPMC was similar to that of control. The oviposited peak of treated hoppers appeared late as compared to the untreated which showed the peak at early part of the ovipositional period. The longevity and fecundity of C. lividipennis treated with BPMC were significantly reduced as compared with the untreated. Etofenprox also induced fecundity reduction when treated with LDlo, and LDm. However, C. lividipennis treated with sublethal doses of buprofezin showed no redution in logevity and fecundity. From these results, it may be said that buprofezin can be used to control brown planthopper without disrupting of C. lividipennis population in the rice field.

• Journal of Sericultural and Entomological Science
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• v.41 no.1
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• pp.29-35
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• 1999

This experiment was carried out to investigate the effect of silkworm powder, mulberry leaves and mulberry root bark administered to S.D. rat on gastrointestinal function. Plot containing ten percent sericultural products(silkworm powder, mulberry leaves and mulberry root bark) was supplied with S.D. rat. The food efficiency ratio(FER) of S.D. rat fed with sericultural products were 0.1486~0.1573. The transit time also were 512.5~574.0 minutes, and transit speed were 25.05~29.11 mm/min. The pH of S.D. rat's feces fed with sericultural products were 5.95~6.72. The daily amount of S.D. rat's feces were 4.12~5.42g. As above results, sericultural products was evaluated to improve the function of S.D. rat's gastrointestine.

• Journal of Life Science
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• v.21 no.6
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• pp.907-911
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• 2011

Using silkworm Bombyx mori Bm5 cells, we established a stable cell line expressing the human keratinocyte growth factor (hKGF), named by the Bm5-hKGF cell, in which the protein hKGF is synthesized in the cell and secreted in the cell culture supernatant (CCS) at approximately 15-20 ng/ml. When the Bm5-hKGF cell was co-expressed with B. mori protein disulfide isomerase (bPDI) cDNA, its secretion increased by about two times the original amount. Through wound healing migration assay, it was demonstrated that the secreted hKGF included in the CCS has a very powerful biological activity of keratinocyte proliferation. We expect to produce useful human recombinant proteins from silkworm cultured cells in large quantities at low prices.

• Journal of Life Science
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• v.20 no.11
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• pp.1577-1581
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• 2010

Granulocyte colony stimulating factor (G-CSF) is a hematopoietic cytokine that stimulates bone marrow cells to proliferate and differentiate into granulocytes. G-CSF is approved and used for therapeutic purposes. The endoplasmic reticulum (ER) signal peptide of hG-CSF was replaced with silkworm-specific signal peptides to express and efficiently secrete recombinant hG-CSF by silkworm cells. Plasmids that contain cDNAs for hG-CSF and hG-CSF fused with silkworm- specific signal peptides of prophenoloxidase activating enzyme (PPAE), protein disulfide isomerase (PDI), and bombyxin (BX) were constructed. The G-CSF protein was expressed in insect cell line BM5 and was detected by western blot analysis. The cells transfected with plasmids containing rhG-CSF genes with silkworm-specific signal sequences released mature rhG-CSF protein more efficiently than the cells transfected with pG-CSF, the plasmid containing human G-CSF gene, including its own signal sequence. The production of hG-CSF reached maximal level at four days post-transfection and remained at a high level until 7 days post-transfection. These data demonstrate that the modification of the human G-CSF mimic to insect proteins synthesized in ER greatly improves the production of the protein.