• Journal of Sericultural and Entomological Science
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• v.7
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• pp.49-52
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• 1967

In the F$_1$ hybrids and parents of silkworms, the silkworms of 47 blocks in summer and 68 blocks in fall in 1965 were reared in order to know the effect of mortality on the difference of sex ratio. The results analyzed are as follows; 1. In Moran of Japanese strain-parent and Morean x Daedong of F$_1$ hybrid, there is of no effect of an increase and decrease of mortality on the sex ratio. So male is not always stronger than female. 2. In Daedong of Chinese strain-parent, the more the mortality in the blocks is, the higher the survival ratio of male pupa becomes. (Y=0.233x-41.67). 3. As the results mentioned above, the present investigation method of cocoon quality of Chinese strains with the same number of cocoons of both sexes will have to be considered again, according to the cocoon crops, as far as concerned with the reasonable sampling from the population.

• Journal of Sericultural and Entomological Science
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• v.42 no.1
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• pp.58-64
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• 2000

This study was designed to investigate the effects of silk fibroin powder (Mw 500) on oxidative stress and membrane fluidity in liver membranes of rats. Sprague-Dawley (SD) male rats (160$\pm$10g) were fed basic diet (control group), and experimental diets (SEP-2.5 and SFP-5.0 groups) added 2.5 and 5.0 g/kg BW/day for 6 weeks. Cholesterol levels resulted in a significant decrease (12.1% and 9.0%, respectively) in the liver mitochondria and microsomes of SEP-5.0 group compared with control group. Membrane fluidity as significantly increased (16.1% and 16.5%, 5.8% and 17.4%) in the liver mitochondria and microsomes were significantly inhibited (16.1% and 18.3%, 8.1% and 15.1%, respectively) at the SFP-2.5 and SEP-5.0 groups compared with control group. Induced oxygen radicals (BOR) in liver mitochondria and microsomes were significantly inhibited (16.1% and 18.3%, 8.1% and 15.1%, respectively) at the SFP-2.5 and SEP-5.0 groups compared with control group. Induced oxygen radicals (IOR) in liver microsomes were significantly inhibited (17.0% and 26.6%, respectively) at the SFP-2.5 and SFP-5.0 groups compared with control group, but IOR in liver mitochondria was significantly inhibited about 12.3% at the SWP-400 group only compared with control group. Lipid peroxide (LPO) levels were significantly decreased (8.3% and 18.0%, 13.4% and 18.4%, respectively) in the liver mitochondria and microsomes of SFP-2.5 and SFP-5.0 groups compared with control group. Oxidized protein (OP) levels were dose-dependently decreased (5.4% and 11.6%, 19.0% and 24.4%, respaectively) in the iver mitochondria and microsomes of SFP-2.5 and SFP-5.0 groups compared with control group. These results suggest that administration of SFP may play an effective role in attenuating an oxidative stress and increasing a membrane fluidity in liver membranes.

• BMB Reports
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• v.43 no.1
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• pp.52-56
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• 2010

Silk fibroin, produced by the silkworm Bombyx mori, has been widely studied as a scaffold in tissue engineering. Although it has been shown to be slowly biodegradable, cellular responses to degraded silk fibroin fragments are largely unknown. In this study, silk fibroin was added to MG-63 cell cultures, and changes in gene expression in the MG-63 cells were screened by DNA microarray analysis. Genes showing a significant (2-fold) change were selected and their expression changes confirmed by quantitative RT-PCR and western blotting. DNA microarray results showed that alkaline phosphatase (ALP), collagen type-I alpha-1, fibronectin, and transforming growth factor-${\beta}1$ expressions significantly increased. The effect of degraded silk fibroin on osteoblastogenic gene expression was confirmed by observing up-regulation of ALP activity in MG-63 cells. The finding that small fragments of silk fibroin are able to increase the expression of osteoblastogenic genes suggests that controlled degradation of silk fibroin might accelerate new bone formation.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.40
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• pp.10.1-10.6
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• 2018

Background: The objective of this study was to evaluate the changes in gene expression after incubation of cells with proteins released from different silk mat layers. Methods: A silk cocoon from Bombyx mori was separated into four layers of equal thickness. The layers were numbered from 1 to 4 (from the inner to the outer layer). The proteins were released by sonication of a silk mat layer in normal saline. The concentration of proteins was determined by spectrophotometry. They were incubated with RAW264.7 cells, and changes in the expression of genes were evaluated by cDNA microarray analysis and quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR). Results: Layer 1 and 4 groups had higher protein concentrations compared to those in layer 2 and 3 groups. The genes associated with inflammation and angiogenesis showed significantly higher expression in layer 1 and 4 groups. The results of qRT-PCR were in agreement with those of the cDNA microarray analysis. Conclusions: The silk mat from the middle portion of the silkworm cocoon yielded a lower protein release and caused an insignificant change in the expression of genes that are associated with inflammation and angiogenesis.

• Journal of Sericultural and Entomological Science
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• v.1
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• pp.15-21
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• 1960

4231년 농림부산림국에서 송충구제책으로 경기도 임업시험장에서 인공배양한 No.7호균외 수종을 사용할 계획인바 비에 대한 임업시험장 시험보고에 의하면 핵균은 송충에 대하여 맹독성이지마는 잠아에 대하여서는 기독성이 경미하다는 보고 이였으므로 양잠가에 대한 의문을 풀기 위하여 송충 및 잠아에 대한 전염성의 강약을 비교 시험하여 그 독성정도를 구명코저 함. 1. 경기도 임업시험장 연구보고 제1호에 기재된 No.7 호균의 시험성적과 본시험성적과를 대조하면 그 이병률은 일정한 경향을 표시치 않으며 다소 상치된 결과이었다. 즉 별표에 의하면 송충은 72~100% 잠아에 있어서는 4289년도에 0~2% 4290년도이 0~20%였으나 본시험결과 (표 1,2,3)는 송충은 표준구에 6.6% 처리구에 13.3~20%이고 잠아는 5~50%의 이병률이였다. 따라서 송충에는 그 감염도가 높으며 잠아는 그 감염도자 낮다고하는 근거를 인정키 난하다. 2. 본시험에 공시된 접종균 No.7호균은 경기도 임업시험장에서 호칭하는 황황강균(Insarica farinosa)이 었으나 핵균 배양시에 이균이 침입된 관계인지는 모르나 본시험에서 폐사를 검정한 결과 백강균(Botrytis Bassiana)이였다. 따라서 No.7호균에 대한 순도가 의심되며 시험결과의 정확을 기할수가없었다. 3. 경기도 임업시험장연구보고 제1호에 접수된 양년간시검성적에 의하면 경화병균 28종중 가장 이병률이 낮다고하는 No.7호균이 본시험결과에서 잠아에 5~50%의 이병률을 나타내는것으로 보아 소위 경기도 임업시험장에서 순수분리한 균은 어느것이라도 송충에 접종하여 산지에 산포하면 그 균이 중간기생 (인교목, 직교목)을 통하여 야생화되어서 더욱 잠아에 대한 전염력을 강렬하게됨으로 양잠상 위험할것이다. 일본의 소산씨 문헌(경기도 임업시험장도서관)에 의하면 야생혼충에서 전염되는 경화병균의 독성은 잠아에 대하여 강력하다는 점과 $\ulcorner$잠업지조선$\lrcorner$제11호에 전라남도 원잠종제조소 강본태대랑씨의 시험성적(참고문헌)이 이를 여실히 입증하는 바이다. (중략)

• Journal of Sericultural and Entomological Science
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• v.28 no.1
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• pp.30-36
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• 1986

Polyacrylamide gel electrophoresis and autoradiography were applied to investigate the developmental profiles of the major hemplymph proteins (MHPs) and their biosynthesis. In addition, some biochemical methods were also used to isolate and purify the MHPs. The obtained results are summarized as follows. 1. MHP-a began to appear from the 2nd day of the fourth-instar larva while MHP-b and -c were detected first on the 1st day of the fifth-instar larva. All these proteins, however, showed a drastic increase in concentration at the 2nd day of the fifth-instar larva. 2. MHP-b and -c were synthesized in fat body on early day of the fifth-instar larva, but the possibility of MHP-a synthesis in fat body was excluded. 3. MHP-b was isolated and purified by heat-treatment (6$0^{\circ}C$), gel filtration on Sephadex G-100 and column chromatography on DEAE-cellulose and CM-cellulose. Purified MHP-b showed a single band on polyacrylamide gel- and SDS-polyacrylamide gel electrophoresis.

• Food Science of Animal Resources
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• v.44 no.4
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• pp.790-804
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• 2024

This study compared the physicochemical properties of edible insect oils from silkworm (Bombyx mori) pupa (SP), sago palm weevil (Rhynchophorus ferrugineus) larva (PW), and bamboo caterpillar (Omphisa fuscidentalis; BC) to oils from chicken skin (CK), beef back fat (BF), pork back fat (PF), salmon belly (SB), sea bass belly (BB), coconut (C), and peanut (P). The fatty acid profiles and thermal behaviors (crystallization and melting) of the extracted oils were evaluated. PW and BC oils had more saturated fatty acids (SFAs) than CK, PF, SB, BB, and P oils. SP oil had equivalent SFA content to CK and BB oils. Insect oils exhibited similar monounsaturated fatty acid concentrations in all samples, except C oils. PW and BC oils exhibited a higher content of palmitoleic acid than the other oils. SP oils contained polyunsaturated fatty acids similar to those in SB and BB oils, which were higher than those in PW, BC, CK, BF, and PF oils. SP oil also exhibited the highest concentration of α-linolenic acid (C18:3 n-3). Arachidonic acid (0.01-0.02 g/100 g) in all insect oils was lower level compared to CK, BF, PF, SB, and BB oils. SP oil (0.03 g/100 g) exhibited a slightly higher level of eicosapentaenoic acid compared to PW (0.01 g/100 g) and BC (0.01 g/100 g) oils. The insect oils were liquid at ambient temperature, solid below -15℃, and required less energy (∆H_m-max) for melting than other samples. This study indicated that insects, particularly SP, could serve as an alternative source of fat to meet its growing demand.

• Journal of Sericultural and Entomological Science
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• v.23 no.2
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• pp.37-49
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• 1982

Larvae of the silkworm (Bombyx mori L.) were reared during the 5th instar on the four kinds of artificial diets on the basis of the different amounts of soybean meal used as the protein source. In this experiment it was shown that the various levels of protein in the diet affected not only the growth and silk production but the digestibility of the diet. haemolymph protein and uric acid excretion. The results obtained are summarized as follows; 1. By an increase of the level of protein in the diet the apparant digestibility was increased. but the protein digestibility was comparatively decreased. 2. Larval body weight increment was not observed by the 3rd day of the 5th instar, but was increased from the 4th day as the level of protein was increased in the diet. 3. After the 3rd day of the 5th instar, protein content in the hemolymph was increased steeply by an increase of the protein content in the diet. However, the percentage of hemolymph protein to the ingested protein was decreased from the 2nd day of the 5th instar and increased more or less after the 4th day. 4. An increase of the uric acid excretion was observed as the content of protein in the diet was increased but the pattern of the uric acid excretion was different between high and low-protein diet. However, the percentage of the uric acid excretion to the ingested protein and to the hemolymph protein were both decreased steeply after the 2nd day of the 5th instar. 5. It was also evident that the high-protein diet increased the cocoon productivity. 6. It showed that the feed efficiency for body weight increment and silk formation was high by an increase of the level of protein in the diet, but the protein efficiency was not.

• Journal of Sericultural and Entomological Science
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• v.13 no.1
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• pp.23-29
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• 1971

As a result of analyzing the change of material substance of all sorts biochemically and comparing the control with ${\gamma}$-ray irradiation (800${\gamma}$, 40 Min), incubating the silkworm eggs (Bombyx mori L.) as the objective in the process of growth of embyro shortly before hatching, the following conclusion has been found. 1. Ascorbic acid has shown the maximum increase of 319 r/g in the Byong B embyro stage and in other words it has increased during the period of vigorous metabolism of the materials in eggs but it has decreased before hatching after that period. 2. Triglyceride has shown the increase of 27.54 mg/g in the Byong A stage, the early period of incubation and in other words it has increased in the period of activation of cells in eggs but it has gradually decreased during the growth of embyro after that period. Great change of either total cholesterol or free cholesterol has not been shown from the early period till shortly before hatching. 3. Free fatty acid has shown the minimum decrease of 257.4$\mu$ mole/g in the Byong A stage in which triglyceride increases greatly. On the contrary, it has shown the increase of 1, 020.0$\mu$ mole/g in Ki A stage in which triglyceride decreases. As a whole, the fact that free fatty acid increases according to the growth of embyro in eggs has been found. 4. Glucose has shown the increase of 281.2 mg/g in control during tile Pigment stage and it has shown the increase of 179.6 mg/g in ${\gamma}$-ray irradiation during the same period. The difference in quantity between the former and the latter is due to the fact that the growth of embyro has been influenced by the radio active. Glucose has changed with free fatty acid and phosphorus the other way round. 5. Control organic phosphorus has shewh the increase of 5.23mg/g during the Byong B or Ki A in which organ and tissue in the emhyro has been formed. Organic phosphorus in ${\gamma}$-ray irradiation has shown the increase of 5.73mg/g during Ki B. Inorganic phosphorus has shown only a little change in the control and ${\gamma}$-ray irradiation. The phosphorus in both has shown a little quantity in the ${\gamma}$-ray irradiation in the early period of incubation. After the Ki A embyro, it has increased rapidly and it has increased till the hatching more continually than in control. The about results of the research will be helpful and instructive to the betterment and improvement, breeding and management of animals and plants.

• Journal of Sericultural and Entomological Science
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• v.24 no.2
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• pp.55-72
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• 1983

These studies were done to find out any difference, ultrastructural, physical or chemical, between the shells of diapausing and non-diapausing eggs of the silkworm, Bombyx mori L. 1. From the electron-microscopic observation, the egg shells have four distinctive layers. In addition to the four layers, the shells in the diapausing eggs has another layer with low electron density on its surface. 2. The permeability of the egg shell to hydrochloride was much lower in diapausing egg than in non-diapausing egg. Also the permeability changed in the opposite directions with the egg age: the diapausing eggs decreased while non-diapausing ones increased. 3. The permeability increased when the diapausing egg shell was treated with HCl. When they were treated with ether, however, the increase in permeability was much smaller. It seems there was an ether soluble material involved in the content of the egg shell. 4. The diapausing eggs were also much more resistant to desiccation than the non-diapausing ones. The former, when treated with HCl or chilling, became less resistant to desiccation. 5. The positive histochemical response of the egg shell to PAS-Alcian blue and protein stainings suggests presence of abundant proteins and carbohydrates in the egg shell. On the other hand, the staining response to lipid was more positive in the inner layers than in the outer layer of the shell. 6. The egg shell adhesives seems to be mucopolysaccharides produced by colleterial glands, since the oviposited eggs showed a positive responses to carbohydrate and negative to lipid-staining chemicals, but not the mature oocytes in the ovarioles. 7. There were two bands on the electrophoretic pattern of the SH proteins extracted from the egg shells both in the diapausing egg and non-diapausing one: a slow moving major component and a fast moving minor one. However, the electrophoretic mobility showed a difference in the minor components between them. It is evident that the fast moving minor one of non-diapausing egg ran a little further than that of diapausing egg. 8. In amino acids analysis, no significant differences were found in their composition between diapausing and non-diapausing egg and SH proteins contain relatively more glycine and less cystine.