• Journal of Sericultural and Entomological Science
• /
• v.40 no.2
• /
• pp.105-110
• /
• 1998

The baculovirus egt gene encodes an ecdysteroid UDP-glucosyltransferase(EGT) which catalyzes the transfer of glucose from UDP-glucose to the insect moltion hormone ecdysteroid resulting in a functionally inactive ecdysteroid. In baculovirus-infected insect larvae, EGT has been shown block molting and pupation. In this study, we compared the development of 4th and 5th instar silkworm, Bombyx mori, larvae injected with either wild-type bombyx mori nucleopolyhedrovirus (BmNPV) or a mutant BmNPV(BmEGTZ) in which the egt gene was disrupted by the insertion of a lacZ gene cassette. Larvae injected with BmEGTZ died roughly 12 h more rapidly compared to indentical larvae infected with BmNPV. In addition, BmEGTZ- infected larvae prematurely stopped feeding and gain less weight compared to BmNPV-infected larvae. In order to investigate why BmEGTZ-infected larvae died more rapidly than BmNPV-infected larvae, the array of hemolymph proteins in BmEGTZ-or BmNPV-infected larvae were analyzed by SDS-PAGE. The hemolymph of BmEGTZ-infected larvae showed virus-specific proteins, including polyhedrin, about 12 h earlier than the hemolymph of BmNPV-infected larvae

• International Journal of Industrial Entomology and Biomaterials
• /
• v.9 no.2
• /
• pp.225-228
• /
• 2004

Superoxide dismutase (SOD) is an important enzyme which catalyzes superoxide radicals to hydrogen peroxide. A Cu, Zn sod-like gene was found in Bombyx mori nuclear polyhedrosis virus encoding 151 amino acids. To demonstrate its function, a recombinant virus named dsBmNPV with deleted sod gene was constructed. It was discovered that the sod gene was not essential for viral replication. Studies on growth of budded virus in BmN cells and superoxide dismutase and catalase activities in vivo after dsBmNPV infection showed that the titer of dsBmNPV decreased obviously comparing to wild type BmNPV, the sod gene was effective on genomic DNA replication of baculovirus, the peak of SOD activity of silkworm infected with wt-BmNPV appeared between 36 and 48 hrs post infection, and with dsBmNPV, it did not appear. And the changes of CAT activity after infection were similar to SOD activity.

• Proceedings of the Korean Society of Sericultural Science Conference
• /
• 2000.10a
• /
• pp.42-42
• /
• 2000

No Abstract.See Full-text

• International Journal of Industrial Entomology and Biomaterials
• /
• v.31 no.2
• /
• pp.85-89
• /
• 2015

This peptide has antibacterial activity against several Gram-positive and Gram-negative bacteria. Bombyx mori cecropinB1(BmCecB1) is antimicrobial peptides from Bombyx mori and belongs to cecropin family. Antimicrobial peptides are important components of the innate immune systems in all living organism. To produce the BmCecB1 antimicrobial peptide, we constructed transgenic silkworm that expressed BmCecB1 gene under the control BmA3 promoter using piggyBac vector. The use of the 3xP3-driven EGFP cDNA as a marker allowed us to rapidly distinguish transgenic silkworm. Mixtures of the donor vector and helper vector were micro-injected into 600 eggs of bivoltin silkworms, Baegokjam. In total, 49 larvae (G0) were hatched and allowed to develop into moths. The resulting G1 generation consisted of 22 broods, and we selected 2 broods containing at least 1 EGFP-positive embryo. The rate of successful transgenesis for the G1 broods was 9%. We identified 9 EGFP-positive G1 moths and these were backcrossed with wild-type moths. With the aim of identifying a BmCecB1 as antimicrobial peptide, we investigated the Radical diffusion Assay (RDA) and then demonstrated that BmCecB1 possesses high antibacterial activities against Gram-negative bacteria.

• Mycobiology
• /
• v.39 no.3
• /
• pp.158-163
• /
• 2011

This study was conducted to confirm the possible use of female Yangwonjam as a host for synnemata production of Isaria tenuipes in eight local areas in Korea. Silkworm pupation rate, infection rate and synnemata characteristics of I. tenuipes were examined. Normal silkworms had a higher pupation rate than silkworms inoculated with I. tenuipes. The pupae survival percentage of normal silkworm in cocoons was 92.5~97.6%, whereas it ranged from 91.1~95.6% in silkworms sprayed with I. tenuipes. Female Yangwonjam showed the highest survival percentage at 97.6% among the silkworm varieties tested. I. tenuipes infection rate of larvae of 5th instar newly-exuviated silkworms was 89.2~90.7% in the spring rearing season and 98.2~99.3% in the autumn rearing season. Synnemata production of I. tenuipes was excellent in female Yangwonjam with an incidence rate of 98.0% followed by male Yangwonjam (94.1%) and Baegokjam (93.3%) in the spring rearing season. Synnemata living weight ranged from 1.44~0.94 g in the spring rearing season. The female Yangwonjam had the heaviest synnemata weight (1.44 g) in the spring rearing season. The synnemata of I. tenuipes produced on pupae were white or milky-white in color, and were similar in shape and color to wild synnemata collected in Korea.

• Proceedings of the Korean Society of Applied Entomolohy Conference
• /
• 2001.11a
• /
• pp.74-74
• /
• 2001

• Proceedings of the Korean Society of Sericultural Science Conference
• /
• 2001.10a
• /
• pp.75-75
• /
• 2001

no Abstract, See Full Text

• Journal of Sericultural and Entomological Science
• /
• v.6
• /
• pp.18-27
• /
• 1966

This treatise was sat up as a basic study of the artificial diets of silk worm, both nursed and wild, by storing the natural leaves in defarmentizing solution and the results obtained were as followings. 1. Defarmentizer C, a kind of defarmentizer, was developed by the author in order to store any natural diet by soaking them in the solution. 2. The defarmentizer was workable for aerophobic bacteriums, but was not effectable for aerophilic bacteriums or fungus. 3. The defarmentized diet could feed silk worm during winter season. 4. The storing method has found the importance of growthness of the diet leaves and the perfect riped leaves were found as the best condition for the purpose. 5. The perfect riped leaves were softened properly during the soaking to be fed for silk worm. 6. The defarmentizing solution has held almost the same pH value of protein isoelectric point so that the protein extraction be ceased during the soaking process. 7. The utilization of defarmentizer has found an economical value. 5. The analytical results of various wild plant leaves were found to be usable as the artificial diet mixture for general silkworm.

• Microbiology and Biotechnology Letters
• /
• v.24 no.1
• /
• pp.72-76
• /
• 1996

To investigate the expression efficiency of new transfer vector of Bombyx mori nuclear polyhedrosis virus (BmNPV), Escherichia coli lacZ gene was inserted into new transfer vector pBmKSK1, under the control of polyhedrin promoter and expressed in BmN-4 cells and larvae of silkworm, Bombyx mori. The recombinant virus containing lacZ gene was isolated from BmN-4 cells coinfected with transfer vectro pBmKSK1-LacZ and wild type BmNPV genome, and analysed by Southern blotting. The expression of ${\beta}$-galactosidase was characterized by SDS-PAGE, Western blotting and ${\beta}$-galactosidase activity assay. The results showed that the level of expression in silkworm larvae was higher than that of BmN-4 cells.

• International Journal of Industrial Entomology and Biomaterials
• /
• v.4 no.1
• /
• pp.43-49
• /
• 2002

We have cloned cDNAs encoding toxin from the spider, Araneus ventricosus, and constructed a recombinant baculovirus expressing the insecticidal toxin. The cDNAs encoding toxin were cloned from the cDNA library of A. ventricosus. Sequence analysis of the cDNAs encoding the toxin of A. ventricosus revealed that the 240 bp cDNA for AvTox-1 and 192 bp cDNA for AvTox-2 have an open reading frame of 80 and 64 amino acid residues, respectively. The deduced protein sequence of the toxin genes of AvTox-1 and AvTox-2 was aligned to that of the snack Anemonia sulcata and scorpion Centruroides limpidus limpidus, respectively. Northern blot analysis indicated that AvTox-2 toxin gene showed a fat body-spe-cific expression pattern at the transcriptional level. Furthermore, we have explored the possibility of improving baculovirus by incorporating the A. vontricosus toxin gene into Bombyx mori nuclear polyhedrosis virus genome under the control of polyhedrin promoter, The AvTox-2 toxin gene was expressed as approximately 5.8 kDa band in the recombinant baculovirus-injected silkworm larvae. Bioassays with the recombinant virus expressing AvTox-2 on 5th instar silkworm larvae demonstrated a decrease in the time to kill $(LT_{50} days)$ compared to wild-type BmNPV-Kl $(LT_{50} 6.72 days)$ in the injection of 10 viruses. These results indicate that A. ventricosus toxin is a novel member of the spider toxin family, suggesting that the toxin gene can be used in recombinant baculoviruses to reduce insect feeding damage and increase the speed of insect kill.