• Journal of Sericultural and Entomological Science
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• v.53 no.1
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• pp.6-11
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• 2015

Antheraea yamamai silkworm cocoon is considered as a natural biocompatible materials, but can not be used as medical resources due to its difficult processability. In this study, we examined the general characteristics including cocoon shell weight and structural and thermal properties of Antheraea yamamai silkworm cocoon. The cocoon shell weight and thickness of wild silkworm cocoon was 0.528 g and 0.424 mm, respectively. The cocoon has yellow-green color in outside cocoon but white in inner layer cocoon. Amino acid analysis showed that the main amino acid of Antheraea yamamai cocoon is alanine, glycine, serine, aspartic acid, tyrosine and arginine. X-ray diffractometry showed that strong diffraction peaks at $2{\theta}=16.8^{\circ}$, $20.4^{\circ}$, corresponded to ${\beta}$-sheet structure and sharp diffraction peaks at $2{\theta}=15.0^{\circ}$, $24.3^{\circ}$, $30.0^{\circ}$ due to the presence of calcium oxalate on cocoon surface. Antheraea yamamai cocoon was degraded at $370^{\circ}C$. These results might be used as basic information for development of non-textile materials using Anthereae yamamai silkworm cocoon.

• Journal of Sericultural and Entomological Science
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• v.48 no.1
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• pp.11-15
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• 2006

Antheraea yamamai silk fibroin powder was prepared by treatment with HCl. The prepared A. yamamai fibroin hydrolysate was characterized by gel filtration chromatography, amino acid analysis, X-ray diffractometry, circular dichroism analysis, differential thermal analysis, and thermogravimetry. The average molecular weight of A. yamamai powder was about 430 and the major amino acids composed of the powder were Ala and Ser. According to XRD analysis, A. yamamai silk powder showed sharp diffraction peaks at $2{\theta}=20.34^{\circ}\;and\;31.5^{\circ}$. CD spectrum showed a peak around 220 nm and a should 215 nm, assigned to ${\alpha}-helix\;and\;{\beta}-sheet$ structure, respectively. DSC and TGA showed that the maximum degradation temperature of powder was around $250{\sim}270^{\circ}C$. Moreover, no harmful heavy metal was contained in the A. yamamai silk fibroin hydrolysate.

• Journal of Sericultural and Entomological Science
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• v.31 no.2
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• pp.82-90
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• 1989

Antheraea yamamai vitellin was purified from matured eggs by polyacrylamide gel electrophoresis for characterization of its biochemical properties : molecular weight, sugar and lipid composition, amino acid composition and electron microscopic morphology, etc. 1. A yamamai vitellin was composed of two subunits, large and small, showing different mobility in SDS-polyacrylamide gel electrophoresis. 2. The molecular weight of the vitellin was estimated to be approximately 450,000 dalton and the large and small subunits were 174,000 dalton and 44,000 dalton, respectively. 3. The vitellin seemed to be a glycolipoprotein since it showed a positive reaction to coomassie brilliant blue, sudan black B and PAS staining. Both subunits were similiar in this aspect. 4. Lipid of the witellin reveraled several different types including saturated lipids. 5. When the vitellin was incubated at 7$0^{\circ}C$ for 60 minites its apoprotein still cross-reacted to the specific antiserum to the native vitellin. Its sugar components were also detected by PAS staining, but its lipid portion was not detected by sudan black B staining. 6. Its amino acid composition was similar to that of other insects, but its glycine content was peculiarly very high. 7. The vitellin molecule was spherical in shape with a diameter of 14$\pm$0.8nm by negatively.

• Korean journal of applied entomology
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• v.46 no.2
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• pp.295-302
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• 2007

We investigated starvation of hatching larvae, occasional artificial hatching and incubation method to establish year-round rearing of the wild silkmoth, Antheraea yamamai. In the test of starvation of hatching larvae for brushing at a time, the survival rate of the fourth instar of larvae starved for 1 day after hatching in $25^{\circ}C\;and\;5^{\circ}C$ was 83.3% and 96.0%, respectively. The result represents that the survival rate is high at low temperature during starvation. In the occasional artificial hatching test for multi-times rearing of A. yamamai, the useful hatchability is high at $5^{\circ}C$ in case of preserving eggs for 2 months from incubation time, and at both $2.5^{\circ}C\;and\;0^{\circ}C$ in case of over 6 months. A new incubation method with pre-incubation at $15^{\circ}C$ and 24 D photoperiod showed high hatchability about 80% for only 2 days compared with hatching for 5-6 days in traditional incubation method with the preservation at $25^{\circ}C$.

• Journal of Sericultural and Entomological Science
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• v.31 no.2
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• pp.72-81
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• 1989

Antheraea yamamai vitellin was purified from matured eggs by polyacryamide gel electrophoresis, also stage dependent appearance, immunological comparison and relative content of the protein were investigated. 1. Vitellogenin, the precursor of vitellin, was first detected in the larval hemolymph at the late spinning stage by polyacrylamide gel electrophoresis and immunoelectrophoresis. 2. The electrophoretic mobility of the vitellin was identical with that of Bombyx mori and of Bombyx mandarina. However, the specific antiserum against A. uamamai vitellin did not react with either that of Bombyx mori or Bombyx mandarina in immumo-diffusion test. 3. Relative content of A. yamamai vitellin to the total soluble egg protein was 46.0 percent and did not change till eight days after oviposition. But the content started to decline from ten days after oviposition and was negligible in the five or serventeen month old eggs.

• Journal of Sericultural and Entomological Science
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• v.36 no.2
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• pp.130-137
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• 1994

This experiment was conducted to evaluate the reasonable rearing technique of Japanese oak silkworm under the different rearing condition as environment, feeding materials and rearing methods. The results are summerized as follows. The optimum temperature for the indoor rearing of Japanese oak silkworm was 25~26$^{\circ}C$ a in young silkworm and 22~23$^{\circ}C$ in grown silkworm, and generally in the condition of variable day/night temperature the growth of silkworm was faster than in that of constant temperature. The optimum relative humidity for it's growth was 80~90% at young silkworm stage and 60~70% at grown silkworm stage. The photoperiod was not affected to the growth of Japanese oak silkworm. The earlier brushing, the shorter the young silkworm stage, and the cocoon quality improved compared to the later brushing time. As a feeding materials aok (Auercus acutissima Crruthers) leaves were better than those of chestnut tree (Castanea Crenata Siebold & Zuccarini) and feeding value of cultivated oak tree leaves was better than that of natural oak tree leaves. The moving time when revealed the better cocoon production of Japanese oak silkworm from indoor condition to outdoor was 15 days after hatched, and the cocoon production was decreased by the earlier moving to outdoor.

• Journal of Sericultural and Entomological Science
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• v.49 no.2
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• pp.74-76
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• 2007

Antheraea yamamai silk fibroin powder was prepared by treatment with HCl. Amino acid contents of the prepared Antheraea yamamai fibroin hydrolysates were composed of Gly, Ala, Glu, and so on. Biological activities of Antheraea yamamai silk fiborin powder were examined. It is showed about 75% of antioxidation activity compared to the reference ascorbic acid. And it lowered blood glucose level down from 550 mg/dl to 300 mg/dl by serving with wild silk protein.

• Journal of Sericultural and Entomological Science
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• v.52 no.1
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• pp.45-51
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• 2014

A cecropin-A gene was isolated from the immunized larvae of the Japanese oak silkworm, Antheraea yamamai and designed Ay-CecA. The complete Ay-CecA cDNA consists of 419 nucleotides with 195 bp open reading frame encoding a 64 amino acid precursor that contains a putative 22-residue signal peptide, a 4-residue propetide and a 37-residue mature peptide with a theoretical mass of 4046.81. The deduced amino acid sequence of the peptide evidenced a significant degree of identity (62 ~ 78% identity) with other lepidopteran cecropins. Like many insect cecropin, Ay-CecA also harbored a glycine residue for C-terminal amidation at the C-end, which suggests potential amidation. To understand this peptide better, we successfully expressed bioactive recombinant Ay-CecA in Escherichia coli that are highly sensitive to the mature peptide. For this, we fused mature Ay-CecA gene with insoluble protein ketosteroid isomerase (KSI) gene to avoid the cell death during induction. The fusion KSI-CecA protein was expressed as inclusion body. The expressed fusion protein was purified by Ni-NTA immobilized metal affinity chromatography (IMAC), and cleaved by cyanogen bromide (CNBr) to release recombinant Ay-CecA. The purified recombinant Ay-CecA showed considerably antibacterial activity against Gram-negative bacteria, E. cori ML 35, Klebsiella pneumonia and Pseudomonas aeruginosa. Our results proved that this peptide with a potent antibacterial activity may play a role in the immune response of Japanese oak silkworm.

• Proceedings of the Korean Society of Sericultural Science Conference
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• 2000.10a
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• pp.63-63
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• 2000

• Proceedings of the Korean Society of Life Science Conference
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• 2000.09a
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• pp.60-60
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• 2000