• International Journal of Industrial Entomology and Biomaterials
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• v.4 no.1
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• pp.37-41
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• 2002

Heterosis studies on rearing performance of 25 Fl Polyvoltine $\times$ bivoltine (sex-limited cocoon colour) hybrids revealed that manifestation of heterosis was highly significant for majority of the economic traits contributing to more silk yield. Five hybrids namely BL24${\times}$ CSR 19 (SL), BL24${\times}$${\times}$${\times}$${\times}$${\times}$

• Korean Journal of Microbiology
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• v.31 no.1
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• pp.17-21
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• 1993

Eight strains of Bacillus thuringiensis were isolated from soil in Korea and characterized. The isolates were named HL-24, HL-25, HL-33, HL-34, HL-35, HL-38, HL-39, HL-40. Strains HL-24 and HL-25 produced irregular parasporal crystals, HL-33 and HL-35 produced bipyramidal crystals, and others were round form in their cells. The biochemical characteristics of the eight isolates were only minor different in specific characteristics to the known serotypes of Bacillus thuringiensis. The HL-25, HL-33 and HL-34 strains showed resistances to cephalothin, colistin and penicillin G, and HL-39 and HL-40 strains were resistant to penicilin G. The strains of HL-24, HL-25, HL-33 and HL-34 were toxic to Bombyx mori lavae and HL-24, HL-25, HL-38, HL-39 and HL-40 strains killed Culex pipiens 3rd instar larvae. The HL-24 and H25 strains showed lethal activity against two kinds of the larvae, however lethality against mosquito larvae was low.

• International Journal of Industrial Entomology and Biomaterials
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• v.2 no.2
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• pp.107-110
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• 2001

Variations in protein and nucleic acid concentrations were observed in 24 hrs old eggs and hatched larvae of Nistari strain, Bombyx mori, exposed to starvation. Three starvation treatments of 24,48 and 60 hrs were given separately from 0 hr old fifth instar larvae. Biochemical variations were studied in the resultant hatched larvae of one time starved parent, while the eggs obtained from parents receiving starvation in two successive generations were considered for the study. In hatched larvae, protein levers in 24 hrs starvation groups remained significantly higher over control (never starved) while the same was found to be lower in 48 and 60 hrs starvation individuals. The RNA concentration remained significantly higher in all the treated lots. However, DNA content was not found to be significantly altered in hatched larvae after exposure to feeding stress. Protein, RNA and DNA concentration of 24 hrs old eggs produced by all the starved groups of Nistari, which had deceived two consecutive starvation during parental generations, showed higher concentrations of these biomolecules over control. Hence, starvation induced alterations in protein and nucleic acids in eggs and hatched Iarvae are indicative of a preparatory phase adopted by the insect to acclimatise itself and its progeny to stress situations.

• Journal of Sericultural and Entomological Science
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• v.32 no.1
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• pp.49-57
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• 1990

To investigate the pathway of Nuclear Polyhedrosis Virus(NPV) of Bombyx mori in early stage infection of 2nd instar larva, the larval tissues were observed under electron microscope at interval of 6, 12, 24, and 48 hours after virus inoculation. The results are as follows. 1. The intact and enveloped nucleocapsids released from the polyhedra protein in the gut lumen apparently entered with the microvilli. 2. Virus progenies were observed in columnar cell nuclei 24 hours after inoculation, but polyhedra was not seen. The enveloped virus was observed in some of the intercellular spaces between mid-gut cells. 3. Many enveloped virus particles appeared in the basement membrane. These enveloped virus particles passed the basement membrane and gathered at blood cells in heomocoeal. 4. The NPV muliplicates in nuclei of the blood cells and the tracheal cells normally.

• International Journal of Industrial Entomology and Biomaterials
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• v.24 no.2
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• pp.49-55
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• 2012

We previously isolated 9 clones that show stronger signal compared to B. mori cytoplasmic actin gene (BmA3) by using a dot blot hybridization. In this study, we focused on one clone among these clones which has high amino acid homology with elongation factor ${\alpha}$ gene of B. mori. This clone, named $bEF1{\alpha}$ (B. mori elongation factor ${\alpha}$) was ubiquitously expressed in all tissues and developmental stage of B. mori. As result of promoter assay using dual luciferase assay system, we found the highest transcription activity region (-702/+38) in the 5'-flanking region of $bEF1{\alpha}$ gene, which has about 20 fold more intensive promoter activity than BmA3 promoter. Moreover, the $bEF1{\alpha}$ promoter was normally regulated in Bm5, Sf9, and S2 cells. Therefore, we suggest that $bEF1{\alpha}$ promoter may be used more powerful and effectively for transgene expression in various insects containing B. mori as a universal promoter.

• Korean Journal of Pharmacognosy
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• v.36 no.2 s.141
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• pp.129-135
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• 2005

Lectins from Allomyrina dichotoma (ADL) and Bombyx mori (BML) were partially purified by physiological saline extraction, ammonium sulfate fractionation, anion exchange column chromatography on DEAE Sephadex A-50 and gel filtration column chromatography on Sephadex G-200. An assay for cytokine expression was carried out by using reverse transcription polymerase chain reaction(RT-PCR). mRNA isolated from PBMC(human peripheral blood mononuclear cells) were stimulated with ADL(O.D.=0.2) and BML(O.D.=0.1) for various times(1,4,8,24,48 and 72 h) and various cytokine mRNA assessed by RT-PCR were shown as follows: The patterns of bands for IL-1 mRNA of BML were very similar with those from ADL and these bands were decreased along the increasing reaction times after showing a strong band at 1 h. However mRNA expressions for IL-2, IL-6, $IFN{\gamma}$ and $TNF{\alpha}$ showed different patterns between ADL and BML. With the effect of ADL, the expression of IL-2 and IL-6 mRNA were continuously detected until 72 h with the strongest band of IL-2 mRNA at 24 h. The strong bands of $IFN{\gamma}$ mRNA were observed from 4 to 8 h but the strongest one of $TNF{\alpha}$ was just observed at 1 h. Meanwhile with BML, the bands for IL-2 and $IFN{\gamma}$ were increased along the increasing reaction times until 72 h. The strongest bands were showed from 4 to 8 h with IL-6 and at 8 h with $TNF[\alpha}$. To verify quantitatively ELISA was used for assay of protein secretions of the cytokine gene with IL-2 and $IFN{\gamma}$ expressed markedly different in RT-PCR. The highest cytokine secretion for IL-2 was demonstrated at 48 h. The production of $IFN{\gamma}$ was markedly increased at 24 h and secreted highest at 72 h. These result suggest that ADL and BML, as inducers of cytokines, can elicit detectable cytokine mRNA from PBMC within the first few hours of stimulation and maintain the production of cytokines for a few days by the methods of RT-PCR and ELISA.

• International Journal of Industrial Entomology and Biomaterials
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• v.12 no.2
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• pp.81-86
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• 2006

Of all factors that govern productivity in sericulture, the role of silkworm egg is of prime importance. The production of silkworm seed involves a long chain of interdependent and highly specialized conditions. Female moths of Bombyx mori L. commence egg deposition immediately when the moths were decoupled. More than 60% of eggs are deposited within 4 hrs after decoupling i.e. 62.33% in CSR-3, 61.67% in CSR-6, 62.50% in CSR-16 and 63.28% in CSR-17. Almost 90% of eggs were laid in the first 12 hrs (93.13% in CSR-3, 90.81% in CSR-6, 89.71% in CSR-16 and 93.17% eggs in CSR-17) after decoupling. Almost 8 to 10% of more eggs were laid when oviposition period was prolonged upto 48 hrs instead of 24 hrs. The present investigation showed that a significant increase of 45 (8.34%), 50 (9.98%), 41 (8.26%) and 45 (8.30%) (P < 0.01) numbers of more eggs were found between 24 to 48 hrs (T6 to T9) in CSR-3, CSR-6, CSR-16 and CSR-17 races respectively. The findings of present investigation is very important for sericulture industry while producing layings to keep for different hibernation schedule especially for autumn/late autumn crop, female may be allowed for prolonged oviposition to get 8 -10% more eggs and farmer may fetch 8 -10 kg. more cocoon yield/l00 dfls with more income.

• International Journal of Industrial Entomology and Biomaterials
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• v.8 no.2
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• pp.129-133
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• 2004

The breeding work was initiated by utilizing two Japanese hybrids namely C135${\times}$N134 and N137${\times}$C146 along with two evolved Indian breeds, J14 and A24. The breed CSR16 which is characterized with marked larvae and white dumbbell cocoons was evolved from the Japanese hybrid C135${\times}$N134 by crossing with J14, while the breed CSR17 which is characterized with plain larvae and white oval cocoons was evolved from the Japanese hybrid N137${\times}$C146 by crossing with A24. The hybrid of these evolved breeds i.e., CSR16${\times}$CSR17 has shown superior over control hybrid $KA{\times}{NB_4}{D_2}$ and on par with the ruling hybrid of CSR2${\times}$CSR4. The hybrid CSR16${\times}$CSR17 was authorized during 1999 by Central Silk Board, Bangalore, Government of India for commercial exploitation during favourable months based on national level race authorization test.

• International Journal of Industrial Entomology and Biomaterials
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• v.11 no.1
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• pp.75-78
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• 2005

Inheritance of cocoon and shell weight characters in silkworm crosses between sex-limited at larva stage lines, including three (NIG$_{1}$ $\times$ TV$_{3/2}$ ,NIG$_{1}$ $\times$ TBV$_{2/24}$ and NIG$_{1}$ $\times$ B$_{2/6}$ ) from Japanese type and three (NIG$_{2}$ $\times$ B$_{2/6}$ ,TV$_{3/2}$ $\times$ NIG$_{1}$ and NIG$_{2}$ $\times$ TBV$_{2/24}$ ) from Chinese type was studied at Regional Centre for Scientific­Applied Service - Vratza during the period of 2000 ­2002. Inheritance of tested characters in F I was deter­mined through genetic parameters, additiveness (a), dominance (d) and their ratio (d/a). Degree and frequency of transgressions in F$_{2}$ were calculated also. Over dominance (d/a(>) 1) with bigger contribution of the parent with higher value was determined at inheritance tested characters. Transgressions obtained at cocoon and shell weight characters were positive and varied in wide limits. The productivity of parent's lines had defined the variability of genetic parameters for degree and frequency of transgressions. Combination of positive transgressions at cocoon and shell weight characters in F2 hybrid populations from sex-limited at larva stage allow us to select individuals with high productive potential for further use in selection programs.

• BMB Reports
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• v.39 no.6
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• pp.737-742
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• 2006

Open reading frame 60 of Bombyx mori nucleopolyhedrovirus (Bm60) is located between 56,673 and 57,479 bp in the BmNPV genome which encodes 268 amino acid residues with predicted molecular weight of 31.0 kDa. Bm60 and its homologues have been identified in 11 completely sequenced lepidopteran NPVs. The transcript of Bm60 was detected by RT-PCR at 18-72 h post-infection (p.i.), while the corresponding protein could be detected at 24-72 h p.i. in BmNPV-infected BmN cells by Western blot analysis using a polyclonal antibody against Bm60. The expression of Bm60 was inhibited in the presence of Ara-c, an inhibitor of viral DNA synthesis. These results together indicated that Bm60 was a late gene. The size of Bm60 product was found to be a 31 kDa in BmNPV-infected BmN cells, consistent with predicted molecular weight. Immuno-fluoresence analysis showed that the Bm60 product was first detected in the cytoplasm at 24 h p.i and also located in nucleus during later infection. In conclusion, the available data suggest that Bm60 is a functional ORF of BmNPV and encodes a 31kDa protein expressed in the later stage of infection cycle.