• Journal of Sericultural and Entomological Science
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• v.50 no.2
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• pp.140-144
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• 2012

This study was aimed for identification of a useful genetic resources from the entomopathogenic bacteria infected-midgut of the silkworm, Bombyx mori L. We analyzed the appropriately midgut-immunizing condition of $4^{th}$ instar larvae by a feeding infection using several entomopathogenic bacteria. Xenorhabdus nematophila was selected as a suitable bacteria for midgut immunization of Jam 123, B. mori. We constructed a subtraction cDNA library from the mRNA of the immunized midgut, respectively. A total of 1,000 clones were randomly selected from the subtracted cDNA library, and then performed a differential display hybridization analysis with forward and reverse probes. In conclusion, nine clones were identified as differential expressed genes, which presumed that these genes were involved in gut immunity of silkworm. The total number of clones analyzed in this work is not enough to have a brief overview of a understanding on the midgut immunity factors of silkworm. Therefore, further defined studies on these molecules biological roles will give us well-fined information about the innate immune mechanism of silkworm.

• Journal of Sericultural and Entomological Science
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• v.34 no.1
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• pp.15-20
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• 1992

Effects of starvation, ligation, refeeding and methoprene treatment in the feeding phase of the fifth instar larvae of Bombyx mori on the regulation of juvenile hormone esterase(JHE) activity were investigated. Starvation and ligation contributed to the reduction of JHE activity, however, JHE levels in starved larvae were slightly higher than in legated larvae. Haemolymph JEH activity of starved larvae was increased by refeeding, and duration of increasing time of JHE activity after starvation was related to duration of starvation. When starved larvae were applied methoprene topically, JHE activity were not changed at day 0 and 1, but were increased by 1.3-1.4 times between day 2 and 5. When ligated larvae were applied methoprene topically, JHE activity was not changed at day 0, but were increased by 1.9-2.3 times between day 1 and 5. These results suggest that head factor, juvenile hormone(JH) and nutrient are major factors in the regulation of JHE in the feeding phase of the fifth instar larvae of Bombyx mori. Especially JHE might be regulated by the co-operative action of head factor and JH. However, head factor plays important role in the early stage, while JH plays important role thereafter.

• Journal of Sericultural and Entomological Science
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• v.6
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• pp.49-52
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• 1966

It has been reported that the effect of royal jelly on silkworms can be markedly resulted from feeding on royal jelly throughout all the instars. In 1965, I began the experiment in order to know whether it has a practical for rearing, only through feeding silkworms at 1st to 2nd instar, when a comparative little amount of mulberry leaves and labor is needed for rearing. In the method of my experiment, mulberry leaves with different concentration of royal jelly added, 2.5%, 5%, and 10%. respectively, are feeded on silkworms of Sulack ${\times}$ Soyang at 1st and 2nd instar in spring in 1965. However, in the result of the experiment there is not any effect on the survival. the growth speed, the body weight, of the larvae, and the weight of cocoon layer, the cocoon layer ratio, and number of silkworm eggs laid.

• Journal of Sericultural and Entomological Science
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• v.4
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• pp.47-50
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• 1965

It is well known that the mid gut polyhedroses can be a cause of serious disease of silkworm in Japan. In our country, however, this disease has not been discussed up to the present. Author made the experiments to know whether this disease aws infectious or not in our country. The results are as follows: 1. The mid-gut polyhedroses was induced by some artificial treatments, of which the most effective one was low temperature treatment (at 5$^{\circ}C$ for 24 hours) at the 5th instar before first feeding. 2. Author found a few infected silkworms which were reared by a farmer in fall in 1964. It was supposed that the induction of this disease was due to the cumulative effects of the bad conditions on the silkworms. Especially the great cause of this disease depended on the quality of the mulberry leaves.

• International Journal of Industrial Entomology and Biomaterials
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• v.4 no.1
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• pp.43-49
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• 2002

We have cloned cDNAs encoding toxin from the spider, Araneus ventricosus, and constructed a recombinant baculovirus expressing the insecticidal toxin. The cDNAs encoding toxin were cloned from the cDNA library of A. ventricosus. Sequence analysis of the cDNAs encoding the toxin of A. ventricosus revealed that the 240 bp cDNA for AvTox-1 and 192 bp cDNA for AvTox-2 have an open reading frame of 80 and 64 amino acid residues, respectively. The deduced protein sequence of the toxin genes of AvTox-1 and AvTox-2 was aligned to that of the snack Anemonia sulcata and scorpion Centruroides limpidus limpidus, respectively. Northern blot analysis indicated that AvTox-2 toxin gene showed a fat body-spe-cific expression pattern at the transcriptional level. Furthermore, we have explored the possibility of improving baculovirus by incorporating the A. vontricosus toxin gene into Bombyx mori nuclear polyhedrosis virus genome under the control of polyhedrin promoter, The AvTox-2 toxin gene was expressed as approximately 5.8 kDa band in the recombinant baculovirus-injected silkworm larvae. Bioassays with the recombinant virus expressing AvTox-2 on 5th instar silkworm larvae demonstrated a decrease in the time to kill $(LT_{50} days)$ compared to wild-type BmNPV-Kl $(LT_{50} 6.72 days)$ in the injection of 10 viruses. These results indicate that A. ventricosus toxin is a novel member of the spider toxin family, suggesting that the toxin gene can be used in recombinant baculoviruses to reduce insect feeding damage and increase the speed of insect kill.

• Journal of Sericultural and Entomological Science
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• v.21 no.1
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• pp.30-35
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• 1979

This experiment was conducted to investigate the effects of $\alpha$-amylase, added to artificial diet, on the larval growth and on the amount of blood sugar of the silkworm Bombyx mori L.. The artificial diet containing 20% mulberry leaf powder was fed on the 5th instar silkworm. The results obtained were summarized follows: 1. The digestibility in both sexes was increased by feeding artificial diet with $\alpha$-amylase and increase of the digestibility was greater in the female than in the male. 2. Larval body weight was increased in the female but was the male, compared with those in each sex of the control, respectively. 3. There was an increase of the single cocoon weight and cocoon shell weight, as compared with that of the control. 4. It was evident that the artificial diet containing $\alpha$-amylase was more effective than the control, and the effect of the diet was considerable higher in the female than in the male. 5. The amount of the blood sugar on the 7th day of 5th instar was decreased as compared with that of the control.

• Journal of Life Science
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• v.28 no.6
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• pp.697-707
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• 2018

The aim of this study was to investigate the potential effects of extracts from silkworm (Bombyx mori L.) that was fermented with Bacillus subtilis KACC 91157 at the levels of 1%(v/w), 2.5%(v/w), and 5%(v/w) in alcohol-fed rats. Sprague-Dawley rats were divided into seven groups: normal group (N), alcohol treated group (C), silymarin treated group (PC, positive control), 5% silkworm powder treated group (SP5), 1% Bacillus subtilis-fermented silkworm powder treated group (BSP1), 2.5% BSP treated group (BSP2.5), and 5% BSP treated group (BSP5). The activities of AST, ALT, ALP, and LDH in the serum and the triglyceride concentrations in the liver and serum were increased by alcohol feeding but were reduced in the BSP5 group. In addition, the contents of total lipids, free fatty acids, and total cholesterol were increased in the alcohol-fed group but were reduced in the BSP5 group. The activities of ADH, ALDH and ADH, ALDH protein levels in the liver were increased in the BSP5 group. The TBARS contents in the liver, serum, liver mitochondria, and liver microsomes were slightly decreased in the BSP5 group compared to the C group. The hepatocytes in alcohol-fed rats contained numerous large droplets; however, BSP5 treatment prevented alcohol-induced lipid droplet accumulation in the hepatocytes. Based on these results, extracts from Bacillus subtilis-fermented silkworm (Bombyx mori L.) have significant potential for development into a functional health food that can improve alcoholic fatty liver conditions.

• Journal of Sericultural and Entomological Science
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• v.21 no.1
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• pp.36-44
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• 1979

Those studies were examined rearing two varieties on Japanese descent and two varieties of Chinese descent by feeding polluted mulberry leaves, non-polluted ones and water-cleaned ones respectively to find effects of air-pollution on the economic characters of silkworms and analysis of contents of Sulphur and Cadmium in the mulberry leaves and silkworms as followings; 1) Japanese descent of polluted part was delayed about 2.5 days than non-polluted part, Chinese descent was delayed about 4 days or inequal and water-cleaned part was medium in the silkworm larval duration. 2) Results of maximum weight of 5th instal, cocoon layer weight and cocoon weight were decreased in due order non-polluted, water-cleaned and polluted in the factors of mulberry 3) Pupal ratio of Japanese descent was not shown statistical significance, but Chinese descent was revealed it obviously in the factors of mulberry leaves. 4) In the resistance of polluted mulberry leaves, Chinese descent was feeble obviously than Japanese and there were some difference even through among the same varieties. 5) The content of S and Cd of polluted area mulberry leaves was increased about 30% respectively than non-polluted area. 6) The fed part of non-polluted mulberry leaves was S 0.41% and Cd 0.013 ppm water-cleaned part was S 0.47% and Cd 0.024 ppm and polluted part was S 0.52% and Cd 0.042 ppm in the contents of S and Cd of silkworm larvae. 7) The contents of S and Cd didn't make visible injury in mulberry leaves but made it seriously in silkworm larvae. 8) The injury of dust on mulberry leaves was more serious than that of quality of mulberry leaves by air-pollution in the economic characters of silkworm. 9) As above results, Chinese descent should avoid contaminated area and it rearing by water-cleaned mulberry leaves can get noticable results in inevitable case on selection of parents silkworm rearingzone.

• Journal of Life Science
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• v.27 no.9
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• pp.1031-1039
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• 2017

The aim of this study was to investigate the potential effects of extracts from silkworm Bombyx mori L. fermented with Bacillus subtilis KACC 91157 at levels of 5%(v/w) and 10%(v/w) in Sprague-Dawley rats intoxicated with 1%(w/w) orotic acid (OA) for 10 days. The rats were divided into a normal group (N), a control group (C: OA), and treatment groups (SP10: OA + 10% extracts from B. mori L.; BSP5: OA + 5% extracts from B. mori L. fermented with B. subtilis KACC 91157; BSP10: OA + 10% extracts from B. mori L. fermented with B. subtilis KACC 91157). Serum activities of aspartate aminotransferase (AST), alanine transferase (ALT), alkaline phosphatase (ALP), and lactate dehydrogenase (LDH) increased following OA feeding, but the rise was slightly reduced by administration of BSP10. The total lipid, free fatty acid, phospholipid, total cholesterol, and triglyceride contents in serum were significantly lower in the OA treatment groups than in the N group. However, the contents slightly increased following the administration of BSP10. Glutathione concentrations in liver and serum were reduced in the OA-induced fatty liver, but they increased following the administration of BSP10. Hepatocytes in the OA-induced fatty liver contained numerous large droplets. However, SP10, BSP5, and BSP10 feeding prevented OA-induced lipid droplet accumulation in hepatocytes. Accordingly, extracts from silkworm powder fermented with B. subtilis could be an ideal material as a dietary supplement in healthy functional foods to improve the effects of fatty liver.

• Journal of Sericultural and Entomological Science
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• v.53 no.2
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• pp.82-86
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• 2015

This study was carried out to develop the silkworm rearing technique in unused mulberry leaves after harvesting mulberry fruit. The growth of Gwasang No. 2 and Suhyang was very good compared to control cultivar Chungil in leaves size and new branch growth, but new branch and leaves of Daeshim was similar or small to control cultivar Chungil. The number of leaves of Gwasang No. 2 and Suhyang was lower than Chungil, but weight of leaves per tree was heavyer than Chungil. Mulberry leaf yield was Gwasang No. 2 521 kg/10a, Suhyang 189 kg/10a, Daeshim 73 kg/10a, Chungil 1,095 kg/10a. Content of mineral element of all three mulberry cultivars leaf for mulberry fruit production was higher than Chungil in N, P, K, Ca etc. Feeding quantity of silkworm of Gwasang No. 2 and Suhyang was much more than Chungil. Feeding quantity was highest at Suhyang in 96 kg/box. Growth duration of silkworm larvae was not different in all four mulberry culivars but weight of silkworms (5th instar 3rd day) was heavy at Gwasang No. 2 (2.07 g/head) and Suhyang (2.11 g/head) compared to control cultivar Chungil (1.92 g/head). Mortality of silkworms was 14.6% (Gwasang No. 2), 13.3% (Suhyang), 13.9% (Daesim), 12.6% (Chungil) and than higher at elder instar stage. The production amount of silkworm (5th instar 3rd day) was 35.4 kg/box (Gwasang No. 2), 36.6 kg/box (Suhyang), 35.0 kg/box (Daeshim), 33.6 kg/ box (Chungil). Amount of possible rearing silkworms was estimated 3.4box/10 a (Gwasang No. 2), 1.3box/10a (Suhyang), 0.5box/10a (Daeshim), 8.7box/10a (Chungil).