• Journal of Sericultural and Entomological Science
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• v.36 no.1
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• pp.30-36
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• 1994

choChorion(egg-shell) morphology of the F1 hybrid between Bombyx mori and Bombyx mandarina has been observed by scanning electrom microscope and chorion protein was analyzed by electrophoresis. The chorion surface structure of F1 hybrids in the lateral(flat) region was similar to that of maternal line. The F1 hybrids chorion was found to have basically a three layer structure. The middle and inner layer were very much like those of the Bombyx mandarina and Bombyx mori. There were many conic pillar structures in the outer layer of the F1 hybrid, which was similar to Bombyx mandarina. This conic pillar structure had a thin cover layer was more clear in the dorsal and ventral side of the F1 hybrid chorion. The conic pillar structure of Bombyx mandarina was found to be dominant in F1 hybrid chorion irrespective of their maternal line. Major components of chorion protein were analyzed by two-dimensional electrophoresis and found to have isoelectric points in the range of pH 4.0-6.5 and molecular weight 10 to 50 kd. F1 hybrid chorion protein components related directly to those of the maternal line. The conic pillar structure was dominat characteristic and it was present in all F1 hybrid.

• Journal of Life Science
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• v.8 no.4
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• pp.426-430
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• 1998

The molecular relationships have analyzed between the Bombyx mandarina(wild silkworm) and Bombyx mori strains (domesticated silkworm, geographical silkworms). A total of 166 polymorphic RAPD markers amplified from 35 different primers were used to analyze the molecular relationships among thirteen silkworm strains. The genetic similarity coefficient between Bombyx mandarina and Jam305 showed the lowest genetic similarity value with 0.451, Bombyx mandarina and Bibaekjam showed the highest genetic similarity value with 0.958. These strains were classified into Bombyx mandarina(a wild silkworm) and Bombyx mori(twelve domesticated silkworm) groups upon the genetic similary coefficient of 0.55. Further classificient of 0.60; the 1st sub-group (J111, Bibaekjam, $pnd^{ps}$), the 2nd sub-group (Galwon, C18, od yujam, JAM306, C108), the 3rd sub-group(R-hwang, p50), the 4th sub-group(zebra) and the 5th sub-group(JAM305). According to this study, RAPD markers seems to be a valuable tool for molecular relationships and classification among the silkworms.

• Journal of Life Science
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• v.9 no.4
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• pp.341-347
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• 1999

Insects use chitinolytic enzyme to digest chitin in the exoskelton during the molting process. We have isolated and sequenced a chitinase-encoding cDNA from the silkworm, Bombyx mandarina, compared its sequenced with genes encoding chitinolytic enzymes from other sources. The insert DNA in the clone is 2,675 nucleotides long with an open reading frame of 1,695 uncletides that encodes a protein of 565 amino acids with a molecuar weight of 63.4 kDa. The 3' -untranslated region of 889 nucleotides is AT-rich and contains two putative polyadenylation signals. The N-terminal sequence of the encoded protein contains numerous hydrophobic residues characteristic of a leader peptide. The amino acid alignment revealed that the endo-$\beta$-N-acetylglucosaminidase had 83% and 97% homology with M. sexta and B. mori, respectively. The deduced amino acid had two highly conserved region at the amino acid residues 97-111 and 139-148 that were related to the existing chitinase.

• Korean journal of applied entomology
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• v.31 no.1
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• pp.33-36
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• 1992

To establish the succeeding generations of wild silkworms, Bombyx mandarina Moore, massrearing was made in the laboratory. The rearing result was good under high humidity and moderately warm condition. Larval periods were 15 to 25 days and the most of larval period was around 17 days. The pupation rate and the pupal period of most of males and females were 40% and 13 to 25 days, respectively. There were two emergence peaks of males and females, and males emergence peak occurred two or three days faster than females.

• Proceedings of the Korean Society of Sericultural Science Conference
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• 2003.04a
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• pp.42-42
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• 2003

The wild silkworm, Bombyx mandarina, was believed the only ancestor of B. mori, inhabits the limited area of Eastern Asia including China, Korea and Japan. However, the geographic dimorphism of B. mandarina was reported with chromosome number and arylphorin gene. In connection with those dimorphism, we studied the genetic differences of ITS-2 region in rDNA purposing the differentiation and geographic variation within the species of B. mandarina. (omitted)

• Korean journal of applied entomology
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• v.29 no.3
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• pp.157-164
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• 1990

The surface patterns and the structures of transverse section of the egg-shell of the sikmoth, Bombyx mandarina, have been described by scanning electron microscope. Three spatially differentiated cross section, called lamellar, conic pillar and cover layers, are found on the mature eg-shell. Silkmoth chorion proteins were detected more than 80 components from a single chorion by two-dimensional electrophoresis. Major protein components of the egg-shell have bee identified on the basis of their isoelectric points and molecular weights, pH 4-6 and 6-30 kd. Several protein components are found entirely or predominantly in th cover layers.

• Journal of Sericultural and Entomological Science
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• v.41 no.3
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• pp.147-153
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• 1999

Chitinolytic enzymes such as ${\beta}$-N-acetylglucosaminidase are major hydrolases involved in insect molting. We have isolated, sequenced a CDNA encoding ${\beta}$-N-acetylglucosaminidase from the silkworm, Bombyx mandarina, and compared its sequence with genes encoding chitinolytic enyzmes from other sources. The insert DNA in the clone is 3,284 nucleotides long with an open reading frame of 1,788 nucleotides that encodes a protein of 596 amino acids with a molecular weight of 68.2 kDa. There is a 3’-untranslated region composed with 1.479 nucleotides and are several potential polyadenylation signals. The predicted amino acid sequence apparently contains a leader peptide of 23 amino acids. A search of the amino acids sequence databases for sequences similarities to other ${\beta}$-N-acetylglucosaminidases or ${\beta}$-N-acetylhexosaminidases. The highest similarity matched with the enzyme from B. mori, which has a sequence identity of 95%. On the other hand, the identity between the B. mandarina enzyme and those from M. sexta and human are 70% and 24%, respectively.

• Korean journal of applied entomology
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• v.32 no.4
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• pp.420-425
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• 1993

The programme of silkrnoth chorion protem synthetIc changes is autonomous i. e.,it is imple I mented WIth normal kinetics by follicles cultured in isolation in a defined tIssue culture medium. On the basis of protem synthetic profiles, 8 stages of chorwgenesis are defined. Detail a analysis of the proteins of chorion of Bombyx mandarina, reveals more than 17 components by eletrophoretic mobility and synthetic kinetics. We have defined three abbreviated synthetlc s stages, based on the pattern of protein synthesized at early, middle, and late synthetic stages

• International Journal of Industrial Entomology and Biomaterials
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• v.10 no.2
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• pp.101-106
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• 2005

In this study, we describe the Bombyx mandarina hemolin cDNA. A sequence analysis of cDNA revealed a single open reading frame (ORF) of 1233 nucleotides. The deduced 410 amino acid sequence of B. mandarina hemolin contains 4 imunoglobulin (Ig) C-2 type domains. B. mandarina hemolin cDNA showed the highest sequence homology to known those of B. mori. The developmental profile in terms of expression level of hemolin mRNA was determined in the absence of a bacterial challenge. Hemolin mRNA was detected only in mid-gut, but not in hemocytes, fat body, testis, and silkglands. Hemolin mRNA in mid-gut was not detected until the spinning stage of the last instar larva, however, lit dramatically increased at the beginning of spinning and gradually decreased until pupal stage.

• Journal of Sericultural and Entomological Science
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• v.45 no.1
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• pp.18-24
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• 2003

B. mandarina of Korean population apparently differs B. mori in isozyme analysis. Fourteen polymorphism occurred B. mandarina not in B. mori at 6 isozymes, Bph, Bes, Amy-hc, Ies, Ict-D, Ict-E. Korean population has shared with the Korean native strain of B. mori in B genotype of Bes, F of Amy-hc, n of Ict-E, M and S of Ict-H. These 5 genotype were known that detection only Korean native strains of B. mori. Nei's genetic distance based on the genotype of isozyme and hemolymph protein using 4 populations of B. mandarina varied from 0.0350 to 0.0624. The distances of 0.0350 is between Jinju and Chilgok population and between Jinju and Kosung population has the largest distances, 0.0624. In genus of Bombyx, B. mandarina and B. mori, genetic distance varied from 0.3822 to 0.5074. Phylogenetic tree obtained using the subprogram UPGMA of NTSYS represented that Bombyx devided two group, B. mandarina and B. mori. B. mandarina has genetic differences according to the population within the Korean peninsula, but that was not recognized genetic variation or divergence considering low values of genetic distance.