• Journal of Life Science
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• v.29 no.2
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• pp.272-278
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• 2019

The silkworm performs sexual reproduction for the production of its healthy offsprings from generations to generations. Parthenogenesis in the silkworm, Bombyx mori acquires immense use in the development of outstanding homozygouse lines with higher viability, hybrid vigour, combining ability and less phenotypic variability, and it can serve as a powerful tool in controlling sex of the offsprings as well as a useful tool in selection of breeding schemes. However, naturally occuring parthenogenesis in silkworm could not be found so far. Fortunately, artificial induction of parthenogenesis is possible in silkworm. So, it is very important to find out novel methods for induction of parthenogenesis. We investigated to attempt to get a novel parthenogenetic method. Accordingly, parthenogenetic studies on between unfertilized in vivo ovarian eggs of live silkworm moth(novel) and unfertilized in vitro ovarian eggs(conventional) taken out from live silkworm moth were investigated by hot water ($46^{\circ}C$), hot air ($46^{\circ}C$) and low temperature ($0^{\circ}C$ and $-20^{\circ}C$) treatments. The best ratio of parthenogenetic eggs was obtained with in vivo ovarian eggs of live silkworm moth rather than with in vitro ovarian eggs taken out from live silkworm moth in all the treatments. The optimum exposure time absolutely depended upon the temperatures of treatments and the forms of in vivo or in vitro ovarian eggs. From these results, we expect that in vivo artificial parthenogenetic treatments on live silkworm moth will be useful for the higher induction of parthenogenesis in the silkworm, B. mori.

• Journal of Sericultural and Entomological Science
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• v.4
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• pp.79-83
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• 1965

The silkworm eggs and silkworm larvae were treated with X-Rays, and then the mutations were induced artificially. The results obtained are as follows: 1. The best range of time was from 1 to 1.5 seconds to induce the mutations. 2. The silkworm-eggs treated with X-rays were almost malformes, unmoulting or radiation sick. 3. Silkworm-eggs laid by the moth-fed on penicillin in 1963 were also treated with x-rays. Many useful ones were found from them. 4. There is the possibility of silkworm improvement by inducing mutations with x-rays. Further studies are therefore needed in this field.

• International Journal of Industrial Entomology and Biomaterials
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• v.30 no.2
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• pp.75-80
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• 2015

The wet spinning of silk solution has attracted researchers' attention because of 1) unique properties of silk as a biomedical material and 2) easy control of the structure and properties of the regenerated silk fiber. Recently, studies have reported that different silkworm varieties produce silk with differences in the molecular weight (MW) and other mechanical properties of the regenerated silk fibroin (SF) film. In this study, we look at the effect of different Bombyx mori varieties on the wet spinning of SF. Although five regenerated SFs from different silkworm varieties have different MWs and solution viscosity, the wet spinnability and post drawing performance of regenerated SFs were not different. This result is due to low variability in the MW of the regenerated SF samples from the different silkworm varieties. In addition, unlike regenerated SF films, the mechanical properties of wet spun regenerated SF filament were not affected by silkworm variety. This result suggests that the mechanical properties of wet spun SF filament are less affected by MW than those of SF film are.

• Journal of Life Science
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• v.9 no.4
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• pp.375-381
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• 1999

To evaluate the protective effects of extracts of silkworm on carbon tetrachloride-induced hepatotoxicity, serum glutamic-oxaloacetic transaminase, glutamic-pyruvic transaminase and lactic dehydrogenase activities, malondialdehydes values and glutathione-S-transferase activity were measured in ICR mice. Extracts of silkworm was administered orally at 30min after the administration of CCl4 Mice were sacrificed at 24h after the administration of extracts of silkworm. The activities of serum aminotransferase and the hepatic content of lipid peroxide after carbon tetrachloride treatment were markedly increased than normal control but those levels were decreased by the treatment of butanol soluble fraction of silkworm methanol extract. Glutathione S-transferase activity was decreased by carbontetrachloride than control, but also inhibited by the treatment of butanol soluble fraction of silkworm methanol extract.

• International Journal of Industrial Entomology and Biomaterials
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• v.11 no.1
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• pp.1-12
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• 2005

Feed conversion efficiency contributes directly or indirectly on the cost benefit ratio of silkworm rearing and is considered to be an important physiological criterion for evaluating the superiority of silkworm breeds/hybrids. Food intake, assimilation and conversion of indigenous as well as exotic silkworm races are well studied by many researchers. In this review, an attempt has been made to consolidate works on feed conversion aspects of indigenous and exotic silkworm races. The paper also deals with the effect of various factors viz., nutritional, environmental and feeding on food assimilation and conversion parameters of mulberry silkworm.

• International Journal of Industrial Entomology and Biomaterials
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• v.4 no.1
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• pp.57-62
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• 2002

Cationic liposomes complexed with DNA have been extensively utilized for the delivery of reporter or therapeutic genes both in culture and in vivo. We investigated and determined the optimum conditions of a cationic liposome, composed of dimethyldioctadecy-lammonium bromide (DDAB) and dioleoyl phosphati-dylethanolamine UOPE), mediated a reporter plasmid expressing luciferase into insect cell lines (Sf-21 and Bm-N) and silkworm larvae. Together the data demonstrated that Bombyx mori nuclear polyhedrosis virus (BmNPV) genomic DNA (128 kb) was successfully transfected into Bm-5 cells using this liposome. These results suggest that DDAB/DOPE liposome will be useful as delivery agents for gene transfer to insect cells both in vitro and in vivo.

• International Journal of Industrial Entomology and Biomaterials
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• v.6 no.2
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• pp.145-149
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• 2003

Seeing inadequate disinfection and unhygenic condition in rearing area, use of disease resistant silkworm variety is the best option. In order to this, an attempt has been made to develop the resistance to Bombyx mori densonucleosis virus (BmDNV-2) into a susceptible silkworm breed Zhenon1 by cross breeding with a resistant silkworm breed SU12 and exposing the subsequent generations to BmDNV-2 followed by the selection of individuals from the surviving batches. After seven generation the evolved DNV-2 resistant strain showed the significantly higher resistance to BmDNV-2 than control Zhenon1. The economic characters of both of the breeds were almost on par.

• International Journal of Industrial Entomology and Biomaterials
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• v.10 no.1
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• pp.1-10
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• 2005

Parthenogenesis in mulberry silkworm, Bombyx mori L. acquires immense use in the development of outstanding homozygous lines with higher viability, hybrid vigour, combining ability and less phenotypic variability. It can serve as a powerful tool in controlling sex of the offsprings as well as a useful tool in selection. In fact India is the second largest silk producing country in the world next only to China and all the five types of natural silks viz., mulberry, oak tasar, tropical tasar, muga and eri are produced in India. However, little information is available on the role of artificial parthenogenesis in the development of superior silkworm breeds. This paper overviews some important studies carried out on artificial parthenogenesis, and outline of different types of parthenogenesis, methods of induction of artificial parthenogenesis, factors responsible for successful parthenogenetic development, cytogenetics of artificial parthenogenesis and role of artificial parthenogenesis in silkworm breeding. Besides, an attempt is made to describe briefly about parthenogenetic engineering which includes cloning in silkworm, artificial insemination, chimeras, hybridization, chromosomal substitution and recombinant DNA in silkworm.

• International Journal of Industrial Entomology and Biomaterials
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• v.10 no.1
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• pp.69-72
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• 2005

Bleaching powder solution (1 to $5\%$), slaked lime solution (0.1 to $0.5\%$) and formalin (1 and $2\%$) were tested for their efficacy against cytoplasmic polyhedrosis virus and Nosema mylittansis spores to control virosis and pebrine respectively in tasar silkworm, Antheraea mylitta in indoor rearing condition. All the disinfectants tested were found effective in suppressing the infection of virosis and pebrine significantly. Complete inactivation of Antheraea mylitta cytoplasmic polyhedrosis virus (AmCPV) was recorded when treated with $4\%$ bleaching powder, $0.4\%$ slaked lime for 20 min and $2.0\%$ formalin for 30 min. Similarly treatments of $3.0\%$ bleaching powder solution for 20 min and $2.0\%$ formalin for 30 min were found effective in complete inactivation of N. mylittanis spores.

• International Journal of Industrial Entomology and Biomaterials
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• v.2 no.2
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• pp.119-122
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• 2001

Whether Bombyx mori nuclear polyhedrosis virus (BmNPV) can be transmitted to offspring, has been a noticeable question for a long time. When fifth instar larvae of the silkworm were orally inoculated with BmNPV dot hybridization and PCR amplification analysis demonstrated that BmNPV was not detected in the eggs laid by BmNPV productively infected female moths. The results indicated that BmNPV could not be transovarially transmitted.