• International Journal of Industrial Entomology and Biomaterials
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• v.1 no.1
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• pp.9-17
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• 2000

Genetic variation in the domestic silkworm strains (Bombyx mori) and phylogenetic relationships between domestic silkworms and wild silkworms (B. mandarina) were investigated by using a portion of mitochondrial CGI gene sequences. Ten geographic strains of B. mori we sequenced were identical in the 410 bp-section of mitochondrial COI gene. This sequence was also identical to the homologous sequence of the four Gen-Bank-registered strains, but one strain of B. mori differed a single nucleotide (0.2%) from others. MtDNA homogeneity in the B. mori strains appears to be resulted from fixation into the mast frequent mtDNA type during the course of breeding for new strains, in which an extensive indoor rearing and removal of unwanted individuals were accompanied. In the comparisons between domestic and wild silkworms, some wild silkworms were closely related to domestic silkworms (0.2%-1.2% of divergence), but the others were not (2.7%-3.7% of sequence divergence). This result was also reflected in the phylogenetic analyses, showing two independent phylogenetic groups: one including all B. mandarina sequences and the other including both B. mandarina and B. mori sequences. Thus, domestic silkworms may have been derived from the ancestor of B. mandarina, which belongs to this group, alto-ough more extensive study will provide better understanding on this issue.

• International Journal of Industrial Entomology and Biomaterials
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• v.9 no.2
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• pp.167-171
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• 2004

We constructed an oligo-d(T) primed directional cDNA library from the Bombyx mandarina whole larvae. In an effort to isolate genes expressed in the B. mandarina, 227 expressed sequence tags (ESTs) were generated by single-pass sequencing from the cDNA library. Sequence analysis showed that 107 clones (47.1%) were classified into known genes and 120 clones (52.9%) were novel transcripts, which are unknown for their function. Of the 107 known genes, the most abundant gene was found to be actin and followed by serine protease in the expression profile. Among these clones, a serine protease homolog (BmSP) which is a class of proteolytic enzymes isolated. Full-length sequence of the BmSP cDNA clone was 922 bp in length and has an open reading frame of 276 amino acids. The conserved histidine, aspatic acid and serine residues forming the catalytic center as well as cysteine residues contributing to three disulphide bonds also were found in Bmsp gene. mRNA expression analysis revealed a high and specific expression of the gene only in midgut tissue, suggesting that BmSP gene is closely associated with the expression of digestive enzyme.

• Proceedings of the Korean Society of Sericultural Science Conference
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• 2001.04a
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• pp.25-25
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• 2001

No Abstract. See Full-text

• Proceedings of the Zoological Society Korea Conference
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• 1995.10b
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• pp.339.1-339
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• 1995

• 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.30 no.2
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• pp.96-104
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• 1988

Vitellin, the major yolk protein of the silkworm, Bombyx mori was pruified, and its immunological properties and the quantitative changes during embryogenesis were studied. The ovary transplantation into male hosts was also carried out to find its effect on the yolk protein synthesis. The pupal vitellogenin and the egg vitellin of Bombyx mori were purified by DEAE-cellulose column chromatography. These two female specific proteins showed the same mobility in the polyacrylamide gel electrophoresis and the same reaction in the double immunodiffusion test. The immunological identity was also observed between the vitellins of Bombyx mori and Bombyx mandarina. The rudimentary ovaries transplanted into the male hosts of silkworms produced eggs without vitellin, indicating that the yolk precursors synthesized in other female organ beyond the ovary were necessary to produce vitellins. The major yolk protein, vitellin was disintegrated and utilized mostly during late stage of embryogenesis. It was different characteristics from the egg specific protein, which was utilized continuously from the early embryonic stage.

• Journal of Life Science
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• v.8 no.4
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• pp.457-464
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• 1998

As a first step for developing universal genetic transformation vector of dilkmoths., we identified the presence of mariner-like element(MLE) which is one of transposable element discovered from many insects to human species, from Bombyx mori, Bombyx mandarina, Antherae yammamai and Antherae pernyi. We used a degenerative primer pair designed from a transposase gene of Drosophila mauritiana and Hyalophora ceropia MLE. As results, major PCR product of 500bp expected as a part of transposase of MLE was detected from all the slkmoths used of this study using these primer. And hybridization assay using pBmoMAR as a probe DNA that was previously cloned from Bombyx mori by the same primer pair, confirmed the presence of MLE from all the silkmoths. This assay showed also that the endogenous MLE in genome of the silkworm is present as high copy number unlikely Drosophila mauritiana which has 10-20 copy number. This data will be a fundamental genetic information for developing mariner-derived vector to transform the silkmoths and other useful insects.

• Journal of Sericultural and Entomological Science
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• v.29 no.2
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• pp.82-83
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• 1987

The number of chromosomes of the wild mulberry silkworm, Bombyx mandarina, collected in Suwon area in the middle part of Korean peninsula was investigated. The chromosomes were examined after smearing and squashing the testis of the last instar larvae which were at spining stage and the microscopic observation showed that the number of chromosomes of the wild mulberry silkworm was 27.

• International Journal of Industrial Entomology and Biomaterials
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• v.33 no.2
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• pp.113-120
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• 2016

Bombyx mandarina is widely accepted as ancestor of B. mori. Silkworms are served as well-characterized models for understanding the mechanism for the genetic regulation of development. In this study, we performed RNA-Seq analysis to examine tissue-expression of gloverin isoforms of the silk-gland, mid-gut, and fat body in B. mandarina. BLAST analysis revealed that four gloverin isoform gene sequences of B. mandarina were highly similar to B. mori. To identify the difference between two species, the expression profile of gloverin was measured by semi- RT-PCR analysis. The specific expression of gloverin isoform genes was observed mainly in the fat body from B. mori but not B. mandarina. However, all of tissues in the wild-type silkworm could induce the upregulation of compared with the B. mori. To validate the sudden increase in gloverin gene expression in the mid-gut tissue of B. mandarina, we were using qRT-PCR. Relative mRNA expression rate of gloverin at the wild-type silkworm was much higher than domestic silkworm. Comparative genomics between domesticated and wild silkworms showed different tissue-expression levels in some of immune related genes. These results are suggesting a trend toward decreasing immunity related genes expression during domestication. Further studies are needed to elucidate the silkworm domestication and an invaluable resource for wild silkworm genomics research.

• Proceedings of the Korean Society of Sericultural Science Conference
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• 2002.10a
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• pp.46-46
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• 2002

No Abstract, See Full Text