• Journal of Sericultural and Entomological Science
• /
• v.42 no.2
• /
• pp.99-103
• /
• 2000

This study was carried out to investigate incubating characteristics, LTSEM observation, nature of a disease of infected silkworms(bombyx mori), LD$\_$50/, optimum infective condition for mass production and infection percentage(%) on conservation periods. On the V8 media, the colony was 0.5∼2.0cm/8 days in diameter and white or slighty colored with a white fluffy to powdery appearance. The conidia was subglobos in shape, zig-zag appearance, 1-celled, hyaline and 3.2$\times$2.4 ㎛ in size on the average. The conidiophore was irregular grouped, hyaline, rounded or flask-shaped. The LD$\_$50/ values of the 2nd and 4th silkworms were each other 6.6142(Log) in natural temperature and humidity (25$\^{C}$, 65%). On optimum infective condition for mass production, all of preservation time(hr.) postinoculation in 1.0$\times$10$\^$8/ conidia/㎖ was over 97% and only 20 hr in 1.0$\times$10$\^$7/ condia/㎖ was over 90%.

• International Journal of Industrial Entomology and Biomaterials
• /
• v.4 no.1
• /
• pp.31-36
• /
• 2002

Peptidohlycan recognition protein (PGRP) is one of the pattern recognition proteins in innate immunity of insect. We isolated differentially expressed two cDNAa, BTL-LPI and BTL-LP2, in the fat body of Bombyx mori larvae injected with bacteria by subtractive hybridization method. These two clones showed amino acid sequence divergence of 30.4%. In the comparison with other insect PGRP genes, BTL-LP2 showed 48.8% and 45.2% of sequence homology to the known PGRP genes of Bombyx mori and Tricoplusia ni, respectively, and BTL-LP2 was 31.8% and 30.9% , respectively. Phylogenetic analysis showed relatively close relationship of the BTL-LP2 to the known insect PGRP, unlike BTL-LPI, which was equidistant both to insect and mammals, suggesting a divergent relationships of the two newly cloned B. mori PGRP genes. Northern blot analyses confirmed an induction of the expression of BTL-LP2 by the bacterial infection in the Int body of B. mori, suggesting the involvement of the gene in the insect immunity.

• International Journal of Industrial Entomology and Biomaterials
• /
• v.1 no.1
• /
• pp.35-40
• /
• 2000

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

• Preventive Nutrition and Food Science
• /
• v.21 no.3
• /
• pp.165-170
• /
• 2016

Recent trial results suggest that the consumption of a low glycemic index (GI) diet is beneficial in the prevention of high blood glucose levels. Identifying active hypoglycemic substances in ordinary foods could be a significant benefit to the management of blood glucose. It has been hypothesized that noodles with Bombyx mori powder are a low GI food. We evaluated GI and changes in postprandial glucose levels following consumption of those noodles and compared them with those following consumption of plain wheat flour noodles (control) and glucose (reference) in healthy subjects. Thirteen males (age: $34.2{\pm}4.5years$, body mass index: $23.2{\pm}1.1kg/m^2$) consumed 75 g carbohydrate portions of glucose and the 2 kinds of noodle after an overnight fast. Capillary blood was measured at time 0 (fasting), 15, 30, 45, 60, 90, 120, and 180 min from the start of each food intake. The GI values were calculated by taking the ratio of the incremental area under the blood glucose response curve (IAUC) for the noodles and glucose. There was a significant difference in postprandial glucose concentrations at 30 and 45 min between the control noodles and the noodles with Bombyx mori powder: the IAUC and GI for the noodles with Bombyx mori powder were significantly lower than those for glucose and plain wheat flour noodles. The wheat flour noodles with Bombyx mori powder could help prevent an increase in postprandial glucose response and possibly provide an alternative to other carbohydrate staple foods for glycemic management.

• International Journal of Industrial Entomology and Biomaterials
• /
• v.37 no.2
• /
• pp.49-54
• /
• 2018

To artificially enhance antimicrobial peptide expression in Bombyx mori, we constructed genetically engineered silkworms overexpressing Rel family transcription factor. The truncated BmRelish1 (BmRelish1t) gene contained a Rel homolog domain (RHD), nuclear localization signal (NLS), acidic and hydrophobic amino acid (AHAA)-rich region, and death domain (DD), but no ankyrin-repeat (ANK) domain. The BmRelish1t gene was controlled by B. mori cytoplasmic actin 3 promoter in the PiggyBac transposon vector. Chromosome analysis of G1 generations of a transgenic silkworm with EGFP expression confirmed stable insertion of BmRelish1t. BmRelish1t gene overexpression in transgenic silkworms resulted in higher mRNA expression levels of B. mori antimicrobial peptides such as lebocin(~20.5-fold), moricin(~8.7-fold), and nuecin(~17.4-fold) than those in normal silkworms.

• International Journal of Industrial Entomology and Biomaterials
• /
• v.9 no.1
• /
• pp.35-40
• /
• 2004

Bombyx mori densonucleosis virus type 1 (BmDNV1)- a non occluded virus causes flacherie disease in the susceptible stocks of the silkworm, Bombyx mori. However, some stocks are non-susceptible. Non-susceptibility to BmDNV1 in B. mori is a unique case where the virus infection is completely inhibited by a single gene of the host. A survey conducted by this institute in some parts of Karnataka state has revealed that, 43.05% of the total incidence of flacherie disease caused by non-occluded viruses, are due to the synergistic infection of B. mori densonucleosis and infectious flacherie virus. Earlier study indicated that rearing of BmDNV1 resistant silkworm stock is effective in protecting silkworm against BmIFV also. In the present study the response of 78 silkworm stocks which include 42 of non-diapausing and 36 of diapausing groups, to BmDNV1 is investigated. Newly ecdysed third instar larvae were inoculated per-os with 10% inoculum of BmDNV1 extracted from the mid-gut of infected silkworm. One non-diapausing and three diapausing silkworm stocks were found to be resistant to BmDNV1. Eleven silkworm stocks were found to possess moderate resistance whereas rest sixty three were found to be susceptible to BmDNV1. Genetic analysis has shown that the resistance to BmDNV1 is autosomally inherited and controlled by a major dominant or a major recessive gene in different silkworm stocks. These resistant stocks can be utilized as the resource material to develop BmDNV1 resistant commercial hybrids. The selection strategies, depending upon the mode of inheritance of resistance in the resource material chosen, are discussed.

• Korean journal of applied entomology
• /
• v.41 no.4
• /
• pp.279-284
• /
• 2002

Flacherie symptom was found in the fifth instar larvae of silkworm, Bombyx mori. The bacterial pathogen was isolated from the hemolymph of the infected silkworm and identified. The isolated bacteria caused a significant flacherie pathogenicity to the fifth instar larvae of B. mori when $5{\times}10^{6}$ cfu (colony-forming unit) of the bacteria was injected into each larva. The infected larvae began to die at 6 days after injection and resulted in complete mortality at 10 days. The bacterium was identified as Staphylococcus gallinarum based on the morphological and physiological characteristics described in Bergey's manual. This identification was further supported by the characters of carbohydrate utility analyzed from a bacterial identification system ($MicroLog^{\circledR}$) and also by the molecular structure of 165-23S rDNA internal transcribed spaces. As an insecticidal action, S. gallinarum caused hemolymph septicemia by its cytotoxic effect on the hemocytes of B. mori.

• International Journal of Industrial Entomology and Biomaterials
• /
• v.9 no.1
• /
• pp.123-126
• /
• 2004

The actin-binding protein profilin cDNA was firstly isolated from the lepidopteran insect, silkworm Bombyx mori. The B. mori profilin cDNA contains an open reading frame of 378 bp encoding 126 amino acid residues and possesses three cysteine residues. The deduced amino acid sequence of the B. mori profilin cDNA showed 80% identity to Apis mellifera profilin and 72% to Drosophila melanogaster profilin. Northern blot analysis showed that B. mori profilin is highly expressed in epidermis and less strongly in silk gland. In addition, Northern blot analysis revealed the presence of B. mori profilin transcripts in all tissues examined, suggesting that B. mori profilin gene is expressed in most, if not all, body tissues.

• International Journal of Industrial Entomology and Biomaterials
• /
• v.21 no.2
• /
• pp.163-167
• /
• 2010

[ $\alpha$ ]Glucosidase (EC 3.2.1.20) is a glycosidase that hydrolyzes disaccharides, oligosaccharides, and polysaccharides resulting in the release of α-D-glucose. In this study, $\alpha$-glucosidase activity in the hemolymph and midgut of the mulberry silkworm Bombyx mori and Japanese oak silkmoth Antheraea yamamai was measured using maltose, sucrose, trehalose, and p-nitrophenyl $\alpha$-D-glucopyranoside as substrates. In general, hemolymph $\alpha$-glucosidase activity was higher in B. mori than in A. yamamai. In contrast, midgut $\alpha$-glucosidase activity was higher in A. yamamai than in B. mori for all of the substrates tested. $\alpha$-Glucosidase activity in the midgut of both B. mori and A. yamamai showed similar responses to changes in pH and temperature for all of the substrates tested. Native (7.5%) PAGE of hemolymph and midgut proteins from B. mori and A. yamamai followed by staining with 4-methylumbelliferyl $\alpha$-D-glucoside (MUG) indicated that the $\alpha$-glucosidases of these related lepidopterans are functionally similar but structurally different. In comparison to $\alpha$-glucosidase activity from A. yamamai, $\alpha$-glucosidase activity from B. mori was generally less sensitive to the $\alpha$-glucosidase inhibitors, 1-deoxynojirimycin (DNJ), acarbose, and voglibose when the activity was determined using maltose, sucrose, and trehalose.