• International Journal of Industrial Entomology and Biomaterials
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• v.6 no.1
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• pp.75-79
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• 2003

Oral supplementation of zinc chloride to silkworm larvae in different concentrations (30, 60 and 90 ${\mu}g$/ml) to the fourth and fifth instar resulted in a significant increase in commercial traits, like larval weight, silk gland weight, cocooning percentage in lower concentrartion (30 ${\mu}g$) treated group. The female cocoon weight, shell weight and its ratio were significantly increased in 30 and 60 ${\mu}g$ treated groups, male cocoon weight, and shell weight in 30 ${\mu}g$ treated group and its ratio in 60 and 90 ${\mu}g$ treated groups, filament length, weight and moth emergence percentage in all the treated groups and egg productivity in 90 ${\mu}g$ treated group were increased significantly. The remaining groups did not show any significant changes compared with that of carrier control.

• International Journal of Industrial Entomology and Biomaterials
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• v.7 no.1
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• pp.51-57
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• 2003

A cDNA encoding a putative alcohol dehydrogenase (ADH) class III was cloned from the silkworm, Bombyx mono The full length cDNA is 1,385 nucleotides long and contains an open reading frame of 1,128 bp encoding 376 amino acid residues. The B. mon ADH III protein sequence was aligned with ADH III known from various organisms. Interestingly, the protein sequence of B. mon ADH III showed 87% and 85% identity to ADH III from marine fish Sparus aurata and Branchiostoma floridae, respectively, whereas rather low sequence identity (83%) to Drosophila melanogaster ADH III was observed. Northern blot analysis revealed that B. mon ADH III mRNA is expressed in all tissues from larva examined: fat body, midgut, epidermis, silk gland and ovary, with the highest level found in the fat body.

• International Journal of Industrial Entomology and Biomaterials
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• v.17 no.2
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• pp.189-195
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• 2008

The sequence of hydroxypyruvate isomerase gene was obtained in NCBI. In this study, the hydroxypyruvate isomerase gene of Bombyx.mori was identified and annotated with bioinformatics tools. The result was confirmed by RT-PCR, prokaryotic expression, mass spectrographic analysis and sub-cellular localization. The hydroxypyruvate isomerase cDNA comtains a 783bp ORF, and has 4 exons. The deduced protein has 260 amino acid residues with the predicted molecular weight of 29169.30 Da, isoelectric point of 6.10, and contains conserved PRK09997 and Hfi domains. The hydroxypyruvate isomerases of Nasonia vitripennis and Bombyx mori have a high homology. Through RTPCR analysis, we found that this transcript was present in testis, ovary, blood-lymph, fat body, midgut, silk gland and tuba Malpighii. This protein was located in cytoplasm through immunohistochemistry. We submitted the cloned gene under the accession number EU344910. The enzyme has been classified under accession number EC 5.3.1.22.

• International Journal of Industrial Entomology and Biomaterials
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• v.1 no.1
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• pp.47-52
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• 2000

The effect of supplementation with potassium nitrate on economic parameters was analysed following treatment of last larval stadium. The treated larvae showed a significant increase in larval weight at 500$\mu\textrm{g}$/ml and silk gland weight in all the treated groups along with other enhanced larval, cocoon and adult parameters. The larval period was significantly decreased in all the treated groups with increased female and male cocoon weights its shell weights filament lengths at 500$\mu\textrm{g}$/ml. The denier was significantly decreased in all the groups. The filament weight moth emergence percentaged length of the ovariole were unaffected. However, eggs per ovariole, fecundity and hatching percentage significantly decreased compared with the corresponding parameters of the carrier control.

• Journal of Sericultural and Entomological Science
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• v.32 no.1
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• pp.38-43
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• 1990

Effects of topical application of 100, 200 and 300ng/$m\ell$ of 3-indole butyric acid (3IBA) on larval parameters were studied in polyvoltine Pure Mysore breed of B. mori. Each concentration was administered independently, at 36h to III, IV ＆ V instars, at 48h to IV ＆ V instars, and at 72h to V instar larvae. Of the various dosages used, the repeated applications of loons of 3-IBA at 36h to III, IV ＆ V instars resulted in a significant increase in larval weight, silk gland weight, cocoon shell weight and fecundity and a significant decrease in larval duration and cocooning percentage when compared with the corresponding parameters of the untreated controls.

• Proceedings of the Korean Society of Sericultural Science Conference
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• 2004.04a
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• pp.57-57
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• 2004

• Journal of Sericultural and Entomological Science
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• v.53 no.1
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• pp.44-49
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• 2015

We characterized tissue specific-expressed genes in the posterior silk gland of Bombyx mori using by the Annealing Control Primer based differential display-PCR manner. In this study, we isolated 34 differentially expressed PCR amplicons, which one of these was identified as a novel transcript named as ACP-16 (366 bp), its expression was observed only in the posterior silk glands by Northern blot analysis. To determine promoter region of the ACP-16, we isolated and analyzed a phage DNA having 1.7 kb-long genome DNA including the open reading flame and 5'- upstream untranslated region of the ACP-16 gene from a genomic DNA library. We have estimated a promoter region of the ACP-16 gene by a web promoter prediction engine, which locates -750 ~ -165 from translation initiation site (ATG, +1). ACP-16 gene is necessary to more studies about critical biological role in order to apply the silkworm's transgenic system.

• International Journal of Industrial Entomology and Biomaterials
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• v.5 no.1
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• pp.79-83
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• 2002

The wild silkmoth, Actias gnoma was firstly collected at Suwon located in the middle part of Korea. The developmental and morphological characteristics of A. gnoma reared under the laboratory conditions were analysed. The egg shape was shorter elliptic. The major and minor diameter of the eggs were 2.04 mm and 1.83 mm, respectively. White mucous material was remained inside the eggs after hatching. Also, the body color of the larvae was completely changed from dark brown to light yellowish-green at the 3rd instar, but it did not occur until pupation. In the feeding test on several plants, the oak tree, Quercus acutissima, was newly identified as a host plant. The final larval instar was mostly 6th, but in some larvae it was 7th. A few of larvae ate their own casts just after ecdysis. The whole larval duration ranged from 45 to 59 days. The single cocoon weight, cocoon shell weight and cocoon shell percentage were 1.65 g,31.3 cg and 18.9%, respectively, The cocoon shape and color were spindle and light brown, respectively. The morphology of the silk gland was greatly different from those of Bombyx mori, Antheraea yamamai and Antheraea peryi: the thickness of the middle and posterior silk glands was almost identical.

• International Journal of Industrial Entomology and Biomaterials
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• v.16 no.1
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• pp.21-27
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• 2008

The expression of heat shock protein genes (Hsp 70, Hsp 40, Hsp 20.8 and Hsp 20.4) against thermal stress in silkworm Bombyx mori was performed through semi-quantitative reverse transcriptase-polymerase chain reaction (RT-PCR). Upon exposure of silkworm to two temperature regimes ($38^{\circ}C$ and $42^{\circ}C$), significant change in the expression of Hsp gene was observed as compared to the control. Hsp 70 and Hsp 40 showed increased expression than the small heat shock protein genes Hsp 20.8 and Hsp 20.4. The Hsp 70 showed increased expression during the recovery period as compared to 1 hr thermal treatments ($38^{\circ}C$/1 hr and $42^{\circ}C$/1 hr). Whereas, Hsp 40, Hsp 20.8 and Hsp 20.4 genes showed higher expression level at initial stages that later gradually decrease during recovery period. Tissue specific expression of Hsp 70 showed variation in the level of expression amongst the tissues. The mid gut and fat body tissues showed higher expression than the cuticle and silk gland tissue. The Hsp 70, Hsp 40 gene expression was analyzed in thermotolerant (Nistari) and thermo susceptible silk worm strain (NB4D2) and results showed significant variation in their expression level. The Nistari showed higher expression of Hsp 70 and Hsp 40 genes than the NB4D2. These findings provide a better understanding of cellular protection mechanisms against environmental stress such as heat shock, as these Hsps are involved in an organism thermotolerance.

• The Korean Journal of Zoology
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• v.33 no.3
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• pp.354-364
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• 1990

The ultrastructure and silk formational process of the flagelliform glands, one of the capture thread producing organs in the orb web spider (Nephila clavata L. Koch), have been studied with electron microscope. A pair of flagelliform glands consist of three distinct regions: excretory duct, storage sac and convoluted tail. This gland is connected to the large spinning tube (spigot) of the posterior spinnerets with two pairs of aggregate glands, and showed a characteristic spigot structure called "triad". The excretory duct consists of three long segments surrounded by the same sheath of connective tissue. The distal duct near the spinning tube bears the electron lucent subcuticles which have the functions of water removal and orientation of the silk fiber, whereas the proximal duct near the sac contains the cuticule precursor transported through the intercellular space. Cytoplasms of the sac and tail regions have well developed rough endoplasmic reticulum and contain the round secretory granules commonly, but the electron densities and internal textures of the granules do not coincided. Adjacent epithelial cells are connected with the specialized septate junctions, and secretory granules accumulated at the apical pole are released to the lumen by the apocrine secretion.secretion.