• International Journal of Industrial Entomology and Biomaterials
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• v.1 no.1
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• pp.73-78
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• 2000

We investigated some biochemical properties of acetylcholinesterase (AChE) in the Bombyx mori larval head. 1% Triton X-100 (v/v) was suitable for extracting AChE from the silkworm larval head but 1 M NaCl was not suitable. PAGE analysis showed a single band of AChE that was detected by histochemical staining using acetylthiocholine as a substrate. AChE was also partially purified with Sepharose 6B and DEAE-cellulose column. Finally, the specific activity of partially purified enzyme solution was 7.6. The study on inhibitor specificity indicated that the enzyme under study was a true cholinesterase (ChE) or AChE. AChE activity was maximum at the substrate concentration of $5{\times}10^{-4}$ M and the excess substrate inhibited the AChE activity. The optimal pH and temperature were pH 7.0-9.0 and 30-35$^{\circ}C$.

• Journal of Sericultural and Entomological Science
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• v.38 no.2
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• pp.130-137
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• 1996

Effect of topical application with 5, 10 and 15${\mu}$g/ml thyroxine on the pre-cocoon, cocoon, postcocoon and silk improvement were studied in bivoltine silkworm NB18 breed of B. mori L. Thyroxine was applied independently on alternate days to silkworm of IV and V instar larvae. The treatment of all different concentrations resulted in a significant increase in commercial characters like larval weight, silkgland weight, cocooning percentage, female cocoon weight and its shell weight and male cocoon shell weight and its ratio, cocoon dimension, length of the filament and its weight and oviposition. However, there was no significant change in larvel weight in 5${\mu}$g/ml treated group and larval duration was significantly decrease. But moth emergence percentage and hatching percentage did not show any significant change when compared with that of carrier control.

• International Journal of Industrial Entomology and Biomaterials
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• v.7 no.1
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• pp.5-10
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• 2003

The nuclear polyhedrosis virus (NPV) resistance of silkworm is controlled by a pair of dominant genes on autosome and micro-effect modificator genes on sex chromosome Z and has the phenomenon of patroclinal inheritance. Based on its hereditary characteristics, methods of preparing near isogenic lines and their $F_2$ populations for screening molecular markers were designed.

• International Journal of Industrial Entomology and Biomaterials
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• v.1 no.2
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• pp.149-153
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• 2000

We have constructed a recombinant baculovirus, Autographa californica nuclear polyhedrosis virus (AcNPV), containing green fluorescent protein (GFP) gene from the jellyfish, Aequorea victoria, and transferred it into the domestic silkworm Bombyx mori larvae for the production of visible transgenic silkworm of living organism. When one day-old fifth instar female larvae were injected with the recombinant AcNPV of 1x10$^{5}$ plaque forming units, the bright glow of GFP was detected in the recombinant AcNPV-infected larvae and in the newly hatched larvae of the next generation. Our findings demonstrate that the viral replication was detected in the silkworm treated with the recombinant ACNPV and the gfp gene was expressed under the transcriptional control of the polyhedrin gene promoter, Furthermore, the gfp gene was transmitted to the next generation, suggesting that this system can be applied for the development of transgenic silkworms.

• Current Research on Agriculture and Life Sciences
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• v.18
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• pp.43-51
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• 2000

Eleven inbred lines of silkworm, Bombyx mori L. were exposed to two main different temperature (23C and 25C) during the larval period in order to elucidate the effect of the temperature differences on their main characters under the, prevailing in Egyptial agro-climactic conditions. The results show that the temperature differences did not affect significantly the pupation ratio and cocoon shell ratio. However, they affected their larval duration to become shorter with the high temperature treatment ($27^{\circ}C$) and their cocoon shell weight and cocoon yield per box of silkworm eggs to be higher in the lower temperature($23^{\circ}C$). It was recommended that some inbred lines should be bred at the 23C throughout the whole larval period, particularly in being reared with high nutritional leaves in order to maximize the hybridization of cocoon yields.

• Journal of Life Science
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• v.23 no.6
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• pp.789-795
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• 2013

Current study was to investigate the potential effects of silkworm, Bombyx mori L. fermented with Bacillus subtilis (BFSP) and Aspergillus kawachii (AFSP) at the 5% (w/w) levels in Sprague-Dawley rats, which was intoxicated with 1% (w/w) orotic acid (OA) for 10 days. The rat group administered silkworm powder showed improvements in fatty liver condition. Consumption of fermented silkworm powder reduced triglyceride concentrations in the liver tissues and serum and increased the serum lipid concentrations to normal levels, thereby aiding in improving fatty liver conditions. These effects were more pronounced in the BFSP than that in SP or AFSP in orotic acid-induced hepatotoxicity and oxidative stress. Based on these results, fermented silkworms are considered to be a material with significant potential for development into a functional health food that can improve fatty liver conditions.

• International Journal of Industrial Entomology and Biomaterials
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• v.8 no.1
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• pp.33-41
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• 2004

The type of trichomes, their density and pattern of distribution on leaves of 16 genotypes of mulberry, belonging to both diploid and polyploid categories, were studied by scanning electron microscope. The present investigation was undertaken to find out the relationship of physical attributes, especially the density and trichome types with higher acceptability and better rearing performance by the silkworm Bombyx-mori L. Two types of trichomes glandular and non-glandular types were observed on both the leaf surfaces of all the mulberry genotypes studied. In general, greater densities of trichomes were observed on the abaxial surface than the adaxial surface of leaves in most of the genotypes. Distribution of glandular trichomes were more in abaxial surface and non-glandular trichomes were more in adaxial surface. Overall, distribution of glandular and non-glandular trichomes per unit area of leaf did not follow any regular pattern. When leaves of those genotypes were fed to silkworms, trichome density was found to be significantly negatively correlated with the survival of larvae i.e., effective rate of rearing, but trichome density did not influence the economic characters of rearing. As the distribution of glandular trichomes (GT) and non-glandular trichomes (NGT) did not follow any definite pattern, no relation could be established between the GT and NGT densities with silkworm rearing performance. However, the ratio of GT and NGT in a particular genotype influenced the rearing parameters, higher the ratios better the rearing performance. High GT and NGT ratio (＞1.00) was found positively significant when correlated with economic parameters viz., larval weight, single cocoon weight and single shell weight. The study is useful in screening different mulberry genotypes for their better acceptability to silk-worm and higher rearing performance at the early stage of selection without actually conducting the rearing.

• International Journal of Industrial Entomology and Biomaterials
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• v.8 no.2
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• pp.151-159
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• 2004

A detailed evaluation of relative toxicity of fluoride to die 5th instar larvae of PM and NB$_4$D$_2$ races of silkworm and the effects of lethal, sublethal and prevailing levels of fluoride in groundwater on the growth, economic characters and fecundity of the silkworm, Bombyx mori (Lepidoptera: Bombycidae) were studied. The feeding of mulberry, Morus alba leaves treated with lethal and sublethal doses of fluoride to PM and NB$_4$D$_2$ races of silkworms from the beginning of the 5th instar to the end of the feeding period resulted in significant reduction in growth, single cocoon weight, single shell weight, silk index, average filament length, and fecundity when compared to controls. These manges were more pronounced on exposure to lethal dose than sublethal dose and in general, the changes induced by fluoride were more striking in NB$_4$D$_2$ than PM, indicating the greater resistance of PM to higher fluoride levels. Groundwater quality in sericulturally important villages of Karnataka and Andhra Pradesh States has been studied with special reference to the presence of fluoride. On exposure to dose of prevailing levels in the waters of sericulturally important areas, die changes observed on growth, economic characters and fecundity were slightly lower when compared to controls and the decrease was found to be insignificant (P$\geq$0.05). It was concluded that, though minute dose (4.0 ppm) of fluoride did not have any toxic impact, it is toxic at higher concentrations to silkworms.

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

• Journal of Sericultural and Entomological Science
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• v.38 no.1
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• pp.7-12
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• 1996

Reproducible the random amplified polymorphic DNAs(RAPDs) patterns were obtained in the two silkworm strains(J111, Galwon) by adjusting concentration optimized of Taq DNA polymerase(one unit), dNTP(200$\mu$M), MgCl2(1.5mM) and template DNA(30ng). In addition, anealing temperature ranging 35$^{\circ}C$ to 42$^{\circ}C$ by the adjusted condition was investigated and fixed at 35$^{\circ}C$ in this study. Variation among individuals and between male and female of Jam 113 strain was not authorized. DNA polymorhpisms among silkworms were authorized by five RAPD markers using OPM04 random primer. Using the primer showing polymorhpims between parents(J111, Galwon) in thirty three individuals, RAPD-PCR for F2 analysis was performed and segregated 3 : 1 in the F2 population. Consequently, RAPDs detected in the parents were obtained as genetic markers, which can be used for construction of genetic map for this industrially particular insect, silkworm Bombyx mori