Comparative study on the mechanical property of silk thread from cocoons of Bombyx mori L.

Science.gov (United States)

Iizuka, E; Hachimori, A; Abe, K; Sunohara, M; Hiraide, Y; Ueyama, A; Kamo, K; Fujiwara, T; Nakamura, F; Uno, T

1983-01-01

Specimens of bave (undegummed silk thread) were collected from cocoons of various origins of parent silkworm races, such as Japanese, Chinese, European, Korean and tropical origins, and from as many races as possible. An apparatus was set up to measure the dynamic elastic modulus of these specimens. In all the categories of the races tested, the elastic modulus was linearly related to the size of bave, regardless of the portion of cocoon layer from which the specimens were taken. This correlation was concluded to be universal to the silk thread of Bombyx mori L. species; however, values of the regression coefficient and of the elastic modulus were susceptible to the origin of silkworm races, depending on whether they were native or improved.

Effects of alkyl polyglycoside (APG) on Bombyx mori silk degumming and the mechanical properties of silk fibroin fibre

Energy Technology Data Exchange (ETDEWEB)

Wang, Fei; Zhang, Yu-Qing, E-mail: sericult@suda.edu.cn

2017-05-01

Alkyl polyglycoside (APG), a nonionic surfactant, is often considered to be a green surfactant and is synthesized using glucose and long chain fatty alcohols. It is used as a degumming agent of Bombyx mori silk fibre in this study for the first time. We studied APG systematically in comparison to the traditional degumming methods, such as aqueous solutions of sodium carbonate (Na{sub 2}CO{sub 3}) and neutral soap (NS). After repeatedly boiling silk fibres in an aqueous solution of 0.25% APG three times for 30 min and using a bath ratio of 1:90–120 (g/mL), sericin was completely removed from the fibre. SDS-PAGE showed that the degumming in APG did not induce an evident breakage of the silk fibroin peptide chains, including the light chain and P25 protein. The tensile properties, thermal analysis, and scanning electron microscopic (SEM) observation of the degummed fibroin fibre all show that APG is a degumming agent similar to NS and far superior to Na{sub 2}CO{sub 3}. These results indicate that APG is an environment-friendly silk degumming/refining agent in the silk textile industry and in the manufacture of silk floss quilts. - Graphical abstract: APG has potential uses as a green degumming/refining reagent for silkworm cocoons or silk fibres in the silk industry and for sericulture production. Display Omitted.

The Effect of Bovine Milk on the Growth of Bombyx mori

OpenAIRE

Konala, Niharika; Abburi, Praveena; Bovilla, Venugopal Reddy; Mamillapalli, Anitha

2013-01-01

Bombyx mori L. (Lepidoptera: Bombycidae) is a well-studied Lepidopteran model system because of its morphology, life cycle, and economic importance. Many scientists have placed importance on enhancing the economic traits of B. mori because it's larvae, silkworms, are vital in the production of silk. In this study, the effect of bovine milk on B. mori growth was tested. Bovine milk contains several components that aid in healthy growth. The treatment was given to fifth instar B. mori larvae be...

Surface modification and properties of Bombyx mori silk fibroin films by antimicrobial peptide

International Nuclear Information System (INIS)

Bai Liqiang; Zhu Liangjun; Min Sijia; Liu Lin; Cai Yurong; Yao Juming

2008-01-01

The Bombyx mori silk fibroin films (SFFs) were modified by a Cecropin B (CB) antimicrobial peptide, (NH 2 )-NGIVKAGPAIAVLGEAAL-CONH 2 , using the carbodiimide chemistry method. In order to avoid the dissolution of films during the modification procedure, the SFFs were first treated with 60% (v/v) ethanol aqueous solution, resulting a structural transition from unstable silk I to silk II. The investigation of modification conditions showed that the surface-modified SFFs had the satisfied antimicrobial activity and durability when they were activated by EDC.HCl/NHS solution followed by a treatment in CB peptide/PBS buffer (pH 6.5 or 8) solution at ambient temperature for 2 h. Moreover, the surface-modified SFFs showed the smaller contact angle due to the hydrophilic antimicrobial peptides coupled on the film surface, which is essential for the cell adhesion and proliferation. AFM results indicated that the surface roughness of SFFs was considerably increased after the modification by the peptides. The elemental composition analysis results also suggested that the peptides were tightly coupled to the surface of SFFs. This approach may provide a new option to engineer the surface-modified implanted materials preventing the biomaterial-centered infection (BCI)

Surface modification and properties of Bombyx mori silk fibroin films by antimicrobial peptide

Energy Technology Data Exchange (ETDEWEB)

Bai Liqiang [Key Laboratory of Advanced Textile Materials and Manufacturing Technology of Ministry of Education, College of Materials and Textile, Zhejiang Sci-Tech University, Xiasha Higher Education Park, Hangzhou 310018 (China); Zhu Liangjun; Min Sijia [College of Animal Sciences, Zhejiang University, Hangzhou 310029 (China); Liu Lin; Cai Yurong [Key Laboratory of Advanced Textile Materials and Manufacturing Technology of Ministry of Education, College of Materials and Textile, Zhejiang Sci-Tech University, Xiasha Higher Education Park, Hangzhou 310018 (China); Yao Juming [Key Laboratory of Advanced Textile Materials and Manufacturing Technology of Ministry of Education, College of Materials and Textile, Zhejiang Sci-Tech University, Xiasha Higher Education Park, Hangzhou 310018 (China)], E-mail: yaoj@zstu.edu.cn

2008-03-15

The Bombyx mori silk fibroin films (SFFs) were modified by a Cecropin B (CB) antimicrobial peptide, (NH{sub 2})-NGIVKAGPAIAVLGEAAL-CONH{sub 2}, using the carbodiimide chemistry method. In order to avoid the dissolution of films during the modification procedure, the SFFs were first treated with 60% (v/v) ethanol aqueous solution, resulting a structural transition from unstable silk I to silk II. The investigation of modification conditions showed that the surface-modified SFFs had the satisfied antimicrobial activity and durability when they were activated by EDC.HCl/NHS solution followed by a treatment in CB peptide/PBS buffer (pH 6.5 or 8) solution at ambient temperature for 2 h. Moreover, the surface-modified SFFs showed the smaller contact angle due to the hydrophilic antimicrobial peptides coupled on the film surface, which is essential for the cell adhesion and proliferation. AFM results indicated that the surface roughness of SFFs was considerably increased after the modification by the peptides. The elemental composition analysis results also suggested that the peptides were tightly coupled to the surface of SFFs. This approach may provide a new option to engineer the surface-modified implanted materials preventing the biomaterial-centered infection (BCI)

Preparation and characterization of regenerated fiber from the aqueous solution of Bombyx mori cocoon silk fibroin

Energy Technology Data Exchange (ETDEWEB)

Zhu Zhenghua [Department of Biotechnology, Tokyo University of Agriculture and Technology, Koganei, Tokyo 184-8588 (Japan); Department of Application Engineering, ZheJiang Vocational College of Economic and Trade, HangZhou, ZheJiang 310018 (China); Imada, Takuzo [Department of Biotechnology, Tokyo University of Agriculture and Technology, Koganei, Tokyo 184-8588 (Japan); Asakura, Tetsuo, E-mail: asakura@cc.tuat.ac.jp [Department of Biotechnology, Tokyo University of Agriculture and Technology, Koganei, Tokyo 184-8588 (Japan)

2009-10-15

The regenerated silk fibers with high strength and high biodegradability were prepared from the aqueous solution of Bombyx mori silk fibroin from cocoons with wet spinning method. Although the tensile strength of the regenerated silk fibroin fiber, 210 MPa is still half of the strength of native silk fiber, the diameter of the fiber is about 100 {mu}m which is suitable for monofilament of suture together with high biodegradability. The high concentration (30%, w/v) of the aqueous solution of the silk fibroin which corresponds to the high concentration in the middle silkgland of silkworm was obtained. This was performed by adjusting the pH of the aqueous solution to 10.4 which corresponds to pK{sub a} value of the OH group of Tyr residues in the silk fibroin. The mixed solvent, methanol/acetic acid (7:3 in volume ratio) was used as coagulant solvent for preparing the regenerated fiber. The structural change of silk fibroin fiber by stretching was monitored with both {sup 13}C solid state NMR and X-ray diffraction methods, indicating that the high strength of the fiber is related with the long-range orientation of the silk fibroin chain with {beta}-sheet structure.

Improved strength of silk fibers in Bombyx mori trimolters induced by an anti-juvenile hormone compound.

Science.gov (United States)

Guo, Kaiyu; Dong, Zhaoming; Zhang, Yan; Wang, Dandan; Tang, Muya; Zhang, Xiaolu; Xia, Qingyou; Zhao, Ping

2018-05-01

Bombyx mori silk fibers with thin diameters have advantages of lightness and crease-resistance. Many studies have used anti-juvenile hormones to induce trimolters in order to generate thin silk; however, there has been comparatively little analysis of the morphology, structure and mechanical properties of trimolter silk. This study induced two kinds of trimolters by appling topically anti-juvenile hormones and obtained thin diameter silk. Scanning electron microscope (SEM), FTIR analysis, tensile mechanical testing, chitin staining were used to reveal that the morphology, conformation and mechanical property of the trimolter silk. Cocoon of trimolters were highly densely packed by thinner fibers and thus had small apertures. We found that the conformation of trimolter silk fibroin changed and formed more β-sheet structures. In addition, analysis of mechanical parameters yielded a higher Young's modulus and strength in trimolter silk than in the control. By chitin staining of silk gland, we postulated that the mechanical properties of trimolters' silk was enhanced greatly during to the structural changes of silk gland. We induced trimolters by anti-juvenile hormones and the resulting cocoons were more closely packed and had smaller silk fiber diameters. We found that the conformation of trimolters silk fibroin had a higher content of β-sheet structures and better mechanical properties. Our study revealed the structures and mechanical properties of trimolter silk, and provided a valuable reference to improve silk quality by influencing molting in silkworms. Copyright © 2018 Elsevier B.V. All rights reserved.

Effect of cocoon fluorescence, silkworm hybrid and gender on sericin content of Bombyx mori L. silk thread

Directory of Open Access Journals (Sweden)

M. Panayotov

2016-06-01

Full Text Available Abstract. The goal of the present study was to determine the influence of the ultraviolet fluorescence of cocoons, the hybrid, the sex and the interaction among them on the sericin content in silk threads. The study was performed with 3 di- and 2 tetra-cross silkmoth (Bombyx mori L. hybrids, differentiated in three groups – with violet, intermediate and yellow fluorescence of the cocoons. The examined factors had a significant effect (p≤0.001 on the sericin content. The highest sericin content was detected in the silk threads of the violet-fluorescent and the lowest – in the yellow-fluorescent group. The analysed di-hybrids were distinguished by better characteristics in terms of sericin content, compared to the tetra-hybrids, most obvious for the yellow-fluorescent fraction.

Glycerin-Induced Conformational Changes in Bombyx mori Silk Fibroin Film Monitored by (13)C CP/MAS NMR and ¹H DQMAS NMR.

Science.gov (United States)

Asakura, Tetsuo; Endo, Masanori; Hirayama, Misaki; Arai, Hiroki; Aoki, Akihiro; Tasei, Yugo

2016-09-09

In order to improve the stiff and brittle characteristics of pure Bombyx mori (B. mori) silk fibroin (SF) film in the dry state, glycerin (Glyc) has been used as a plasticizer. However, there have been very limited studies on the structural characterization of the Glyc-blended SF film. In this study, (13)C Cross Polarization/Magic Angle Spinning nuclear magnetic resonance (CP/MAS NMR) was used to monitor the conformational changes in the films by changing the Glyc concentration. The presence of only 5 wt % Glyc in the film induced a significant conformational change in SF where Silk I* (repeated type II β-turn and no α-helix) newly appeared. Upon further increase in Glyc concentration, the percentage of Silk I* increased linearly up to 9 wt % Glyc and then tended to be almost constant (30%). This value (30%) was the same as the fraction of Ala residue within the Silk I* form out of all Ala residues of SF present in B. mori mature silkworm. The ¹H DQMAS NMR spectra of Glyc-blended SF films confirmed the appearance of Silk I* in the Glyc-blended SF film. A structural model of Glyc-SF complex including the Silk I* form was proposed with the guidance of the Molecular Dynamics (MD) simulation using ¹H-¹H distance constraints obtained from the ¹H Double-Quantum Magic Angle Spinning (DQMAS) NMR spectra.

Microstructural, thermal and antibacterial properties of electron beam irradiated Bombyx mori silk fibroin films

Energy Technology Data Exchange (ETDEWEB)

Asha, S.; Sanjeev, Ganesh, E-mail: ganeshsanjeev@rediffmail.com [Microtron Center, Department of Studies in Physics, Mangalore University, Mangalagangotri - 574199 (India); Sangappa [Department of Studies in Physics, Mangalore University, Mangalagangotri - 574199 (India); Naik, Prashantha; Chandra, K. Sharat [Department of Biosciences, Mangalore University, Mangalagangotri - 574199 (India)

2014-04-24

The Bombyx mori silk fibroin (SF) films were prepared by solution casting method and the effects of electron beam on structural, thermal and antibacterial responses of the prepared films were studied. The electron irradiation for different doses was carried out using 8 MeV Microtron facility at Mangalore University. The changes in microstructural parameters and thermal stability of the films were investigated using Wide Angle X-ray Scattering (WAXS) and thermogravimetric analysis (TGA) respectively. Both microstructuralline parameters (crystallite size and lattice strain (g in %)) and thermal stability of the irradiated films have increased with radiation dosage. Agar diffusion method demonstrated the antibacterial activity of SF film which was increased after irradiation on both Gram-positive and Gram-negative species.

Silk fibroin film from golden-yellow Bombyx mori is a biocomposite that contains lutein and promotes axonal growth of primary neurons.

Science.gov (United States)

Pistone, Assunta; Sagnella, Anna; Chieco, Camilla; Bertazza, Gianpaolo; Varchi, Greta; Formaggio, Francesco; Posati, Tamara; Saracino, Emanuela; Caprini, Marco; Bonetti, Simone; Toffanin, Stefano; Di Virgilio, Nicola; Muccini, Michele; Rossi, Federica; Ruani, Giampiero; Zamboni, Roberto; Benfenati, Valentina

2016-05-01

The use of doped silk fibroin (SF) films and substrates from Bombyx mori cocoons for green nanotechnology and biomedical applications has been recently highlighted. Cocoons from coloured strains of B. mori, such as Golden-Yellow, contain high levels of pigments that could have a huge potential for the fabrication of SF based biomaterials targeted to photonics, optoelectronics and neuroregenerative medicine. However, the features of extracted and regenerated SF from cocoons of B. mori Golden-Yellow strain have never been reported. Here we provide a chemophysical characterization of regenerated silk fibroin (RSF) fibers, solution, and films obtained from cocoons of a Golden-Yellow strain of B. mori, by SEM, (1) H-NMR, HPLC, FT-IR, Raman and UV-Vis spectroscopy. We found that the extracted solution and films from B. mori Golden-Yellow fibroin displayed typical Raman spectroscopic and optical features of carotenoids. HPLC-analyses revealed that lutein was the carotenoid contained in the fiber and RSF biopolymer from yellow cocoons. Notably, primary neurons cultured on yellow SF displayed a threefold higher neurite length than those grown of white SF films. The results we report pave the way to expand the potential use of yellow SF in the field of neuroregenerative medicine and provide green chemistry approaches in biomedicine. © 2016 Wiley Periodicals, Inc.

Microscopic structural analysis of fractured silk fibers from Bombyx mori and Samia cynthia ricini using 13C CP/MAS NMR with a 1 mm microcoil MAS NMR probehead

KAUST Repository

Yamauchi, Kazuo; Yamasaki, Shizuo; Takahashi, Rui; Asakura, Tetsuo

2010-01-01

Conformational changes have been studied in silk fibers from the domestic silkworm Bombyx mori and a wild silkworm Samia cynthia ricini as a result of fractured by stretching. About 300 samples consisting of only the fractured regions of [1-13C

Combined Effect of Cameo2 and CBP on the Cellular Uptake of Lutein in the Silkworm, Bombyx mori

Science.gov (United States)

Dong, Xiao-Long; Chai, Chun-Li; Pan, Cai-Xia; Tang, Hui; Chen, Yan-Hong; Dai, Fang-Yin; Pan, Min-Hui; Lu, Cheng

2014-01-01

Formation of yellow-red color cocoons in the silkworm, Bombyx mori, occurs as the result of the selective delivery of carotenoids from the midgut to the silk gland via the hemolymph. This process of pigment transport is thought to be mediated by specific cellular carotenoids carrier proteins. Previous studies indicated that two proteins, Cameo2 and CBP, are associated with the selective transport of lutein from the midgut into the silk gland in Bombyx mori. However, the exact roles of Cameo2 and CBP during the uptake and transport of carotenoids are still unknown. In this study, we investigated the respective contributions of these two proteins to lutein and β-carotene transport in Bombyx mori as well as commercial cell-line. We found that tissues, expressed both Cameo2 and CBP, accumulate lutein. Cells, co-expressed Cameo2 and CBP, absorb 2 fold more lutein (PBombyx mori. Cameo2 and CBP, as the membrane protein and the cytosol protein, respectively, have the combined effect to facilitate the cellular uptake of lutein. PMID:24475153

Gamma radiation effects of 60 Co on Bombyx mori (Lep., Bombycidae) modifying the silk fiber production

International Nuclear Information System (INIS)

Carneiro Junior, Francisco; Bendassolli, Jose A.

1997-01-01

The present work aimed to verify the biological effects of the application of different doses of gamma radiation during the fifth instar of the silkworm catepillar. Sevently eight silkworm caterpillars (Bombyx mori) were irradiated with γ 60 Co radiation at the initial period of the fifth instar. The caterpillars were divided and classified in six batches of thirteen individuals each. Treatments 1 through 5 received 20, 40, 60, 80 and 100 Gy, respectively, and the control, also consisted of thirteen caterpillars, was not irradiated. The results showed a general increase in the silk fiber content in the irradiated batches compared to the control. The weight of the silk cocoons was higher with increasing doses of irradiation, from 20 to 80 Gy, respectively, followed by a decrease in weight in the treatment irradiated with 100 Gy. the results obtained in this experiment enable the conclusion that the radiation applied to the caterpillars significantly influenced the production of silk fiber in this species. (author). 4 refs., 2 figs., 3 tabs

Effect of Venom from the Jellyfish Nemopilema nomurai on the Silkworm Bombyx mori L.

Science.gov (United States)

Yu, Huahua; Li, Rongfeng; Chen, Xiaolin; Yue, Yang; Xing, Ronge; Liu, Song; Li, Pengcheng

2015-09-24

The silkworm Bombyx mori L. (B. mori) has a significant impact on the economy by producing more than 80% of the globally produced raw silk. The exposure of silkworm to pesticides may cause adverse effects on B. mori, such as a reduction in the production and quality of silk. This study aims to assay the effect of venom from the jellyfish Nemopilema nomurai on growth, cuticle and acetylcholinesterase (AChE) activity of the silkworm B. mori by the leaf dipping method. The experimental results revealed that the four samples caused neither antifeeding nor a lethal effect on B. mori. The sample SFV inhibited B. mori growth after 6 days of treatment in a dose-dependent manner. The samples SFV, DSFV and Fr-1 inhibited the precipitation and synthesis of chitin in the cuticle after 12 and 14 days of treatment. In the case of the four samples, the AChE was significantly improved after 14 days of treatment.

Transmission Electron Microscopy of Bombyx Mori Silk Fibers

Science.gov (United States)

Shen, Y.; Martin, D. C.

1997-03-01

The microstructure of B. Mori silk fibers before and after degumming was examined by TEM, selected area electron diffraction (SAED), WAXS and low voltage SEM. SEM micrographs of the neat cocoon revealed a network of pairs of twisting filaments. After degumming, there were only individual filaments showing a surface texture consistent with an oriented fibrillar structure in the fiber interior. WAXS patterns confirmed the oriented beta-sheet crystal structure common to silkworm and spider silks. Low dose SAED results were fully consistent with the WAXS data, and revealed that the crystallographic texture did not vary significantly across the fiber diameter. TEM observations of microtomed fiber cross sections indicated a somewhat irregular shape, and also revealed a 0.5-2 micron sericin coating which was removed by the degumming process. TEM observations of the degummed silk fiber showed banded features with a characteristic spacing of nominally 600 nm along the fiber axis. These bands were oriented in a roughly parabolic or V-shape pointing along one axis within a given fiber. We hypothesize that this orientation is induced by the extrusion during the spinning process. Equatorial DF images revealed that axial and lateral sizes of the β-sheet crystallites in silk fibroin ranged from 20 to 170 nm and from 1 to 24 nm, respectively. Crazes developed in the degummed silk fiber parallel to the fiber direction. The formation of these crazes suggests that there are significant lateral interactions between fibrils in silk fibers.

Microscopic structural analysis of fractured silk fibers from Bombyx mori and Samia cynthia ricini using 13C CP/MAS NMR with a 1 mm microcoil MAS NMR probehead

KAUST Repository

Yamauchi, Kazuo

2010-07-01

Conformational changes have been studied in silk fibers from the domestic silkworm Bombyx mori and a wild silkworm Samia cynthia ricini as a result of fractured by stretching. About 300 samples consisting of only the fractured regions of [1-13C]Ala or [1-13C]Gly labeled silk fibers were collected and observed by 13C CP/MAS NMR spectra. The total amount of these fractured fibers is only about 1 mg and therefore we used a home-built 1 mm microcoil MAS NMR probehead. A very small increase in the fraction of random coil was noted for the alanine regions of both silk fibroins and for the glycine region of B. mori silk fibroin. However, there is no difference in the spectra before and after fractured for the glycine region of S. c. ricini silk fibroin. Thus, the influence of fracture occurs exclusively at the Ala region for S. c. ricini. The relationship between sequence, fracture and structure is discussed. © 2010 Elsevier Inc. All rights reserved.

Gamma radiation effects of {sup 60} Co on Bombyx mori (Lep., Bombycidae) modifying the silk fiber production; Influencia da radiacao gama ({sup 60} Co) na producao de fios de seda em Bombyx mori(Lep.,Bombycidae)

Energy Technology Data Exchange (ETDEWEB)

Carneiro Junior, Francisco [Universidade Metodista de Piracicaba (UNIMEP), SP (Brazil); Bendassolli, Jose A. [Centro de Energia Nuclear na Agricultura (CENA), Piracicaba, SP (Brazil)

1997-12-01

The present work aimed to verify the biological effects of the application of different doses of gamma radiation during the fifth instar of the silkworm catepillar. Sevently eight silkworm caterpillars (Bombyx mori) were irradiated with {gamma}{sup 60} Co radiation at the initial period of the fifth instar. The caterpillars were divided and classified in six batches of thirteen individuals each. Treatments 1 through 5 received 20, 40, 60, 80 and 100 Gy, respectively, and the control, also consisted of thirteen caterpillars, was not irradiated. The results showed a general increase in the silk fiber content in the irradiated batches compared to the control. The weight of the silk cocoons was higher with increasing doses of irradiation, from 20 to 80 Gy, respectively, followed by a decrease in weight in the treatment irradiated with 100 Gy. the results obtained in this experiment enable the conclusion that the radiation applied to the caterpillars significantly influenced the production of silk fiber in this species. (author). 4 refs., 2 figs., 3 tabs.

The effect of bovine milk on the growth of Bombyx mori.

Science.gov (United States)

Konala, Niharika; Abburi, Praveena; Bovilla, Venugopal Reddy; Mamillapalli, Anitha

2013-01-01

Bombyx mori L. (Lepidoptera: Bombycidae) is a well-studied Lepidopteran model system because of its morphology, life cycle, and economic importance. Many scientists have placed importance on enhancing the economic traits of B. mori because it's larvae, silkworms, are vital in the production of silk. In this study, the effect of bovine milk on B. mori growth was tested. Bovine milk contains several components that aid in healthy growth. The treatment was given to fifth instar B. mori larvae because the fifth instar period is when B. mori eats voraciously and shows maximum growth among all its larval stages. The larvae were treated with fresh mulberry, Morus L. (Rosales: Moraceae), leaves and mulberry leaves dipped in milk from the first day of the fifth instar. Treatments were given on alternate days, and the silkworms were weighed every day to determine whether milk had any role in enhancing the weight of the larvae. Cocoon weights were measured, as the weight indicates the approximate amount of silk that can be reeled. The results showed that larvae gained 82.5% more weight by the end of fifth instar larval when fed with mulberry leaves dipped in milk than when fed with fresh mulberry leaves without milk. The larvae fed with milk-treated leaves gained 310% weight from day 1 to day 7 of the fifth instar, while the larvae fed with fresh leaves gained 153% weight in the same timespan. In addition, cocoon weight increased by 8% when milk was added compared to when it was not. These results suggest that B. mori larvae can be fed mulberry leaves treated with bovine milk for better growth rate and increased silk production.

Advanced technologies for genetically manipulating the silkworm Bombyx mori, a model Lepidopteran insect

Science.gov (United States)

Xu, Hanfu; O'Brochta, David A.

2015-01-01

Genetic technologies based on transposon-mediated transgenesis along with several recently developed genome-editing technologies have become the preferred methods of choice for genetically manipulating many organisms. The silkworm, Bombyx mori, is a Lepidopteran insect of great economic importance because of its use in silk production and because it is a valuable model insect that has greatly enhanced our understanding of the biology of insects, including many agricultural pests. In the past 10 years, great advances have been achieved in the development of genetic technologies in B. mori, including transposon-based technologies that rely on piggyBac-mediated transgenesis and genome-editing technologies that rely on protein- or RNA-guided modification of chromosomes. The successful development and application of these technologies has not only facilitated a better understanding of B. mori and its use as a silk production system, but also provided valuable experiences that have contributed to the development of similar technologies in non-model insects. This review summarizes the technologies currently available for use in B. mori, their application to the study of gene function and their use in genetically modifying B. mori for biotechnology applications. The challenges, solutions and future prospects associated with the development and application of genetic technologies in B. mori are also discussed. PMID:26108630

Effect of the sterilization method on the properties of Bombyx mori silk fibroin films

Energy Technology Data Exchange (ETDEWEB)

George, Karina A. [Queensland Eye Institute, 41 Annerley Road, South Brisbane, Queensland 4101 (Australia); Institute of Health and Biomedical Innovation, Queensland University of Technology, Kelvin Grove, Queensland 4059 (Australia); Shadforth, Audra M.A. [Queensland Eye Institute, 41 Annerley Road, South Brisbane, Queensland 4101 (Australia); Chirila, Traian V., E-mail: traian.chirila@qei.org.au [Queensland Eye Institute, 41 Annerley Road, South Brisbane, Queensland 4101 (Australia); Australian Institute of Bioengineering and Nanotechnology, University of Queensland, St Lucia, 4072 (Australia); Faculty of Health Sciences, University of Queensland, Herston, Queensland 4006 (Australia); Faculty of Science and Engineering, Queensland University of Technology, Brisbane, Queensland 4001 (Australia); Laurent, Matthieu J. [Queensland Eye Institute, 41 Annerley Road, South Brisbane, Queensland 4101 (Australia); Ecole Superieure d' Ingenieurs de Luminy (ESIL), Universite de la Mediterranee Aix-Marseille II, Luminy case 925 13288, Marseille, Cedex 09 (France); Stephenson, Sally-Anne [Institute of Health and Biomedical Innovation, Queensland University of Technology, Kelvin Grove, Queensland 4059 (Australia); Faculty of Health, Queensland University of Technology, Brisbane, Queensland 4001 (Australia); Edwards, Grant A. [Australian Institute of Bioengineering and Nanotechnology, University of Queensland, St Lucia, 4072 (Australia); Madden, Peter W. [Queensland Eye Institute, 41 Annerley Road, South Brisbane, Queensland 4101 (Australia); Faculty of Health Sciences, University of Queensland, Herston, Queensland 4006 (Australia); and others

2013-03-01

We have compared the effects of different sterilization techniques on the properties of Bombyx mori silk fibroin thin films with the view to subsequent use for corneal tissue engineering. The transparency, tensile properties, corneal epithelial cell attachment and degradation of the films were used to evaluate the suitability of certain sterilization techniques including gamma-irradiation (in air or nitrogen), steam treatment and immersion in aqueous ethanol. The investigations showed that gamma-irradiation, performed either in air or in a nitrogen atmosphere, did not significantly alter the properties of films. The films sterilized by gamma-irradiation or by immersion in ethanol had a transparency greater than 98% and tensile properties comparable to human cornea and amniotic membrane, the materials of choice in the reconstruction of ocular surface. Although steam-sterilization produced stronger, stiffer films, they were less transparent, and cell attachment was affected by the variable topography of these films. It was concluded that gamma-irradiation should be considered to be the most suitable method for the sterilization of silk fibroin films, however, the treatment with ethanol is also an acceptable method. - Highlights: Black-Right-Pointing-Pointer The effects of four methods of sterilization on the properties of silk fibroin films were investigated. Black-Right-Pointing-Pointer Steam treatment leads to stiffer films but to lower transparency and variable surface topography. Black-Right-Pointing-Pointer Degradation of fibroin is enhanced in the films that were gamma-irradiated. Black-Right-Pointing-Pointer The effects on mechanical properties are explained through changes in both primary and secondary structure of fibroin. Black-Right-Pointing-Pointer Gamma-irradiation and immersion in aqueous ethanol are suggested as preferred methods of sterilization.

Effect of the sterilization method on the properties of Bombyx mori silk fibroin films

International Nuclear Information System (INIS)

George, Karina A.; Shadforth, Audra M.A.; Chirila, Traian V.; Laurent, Matthieu J.; Stephenson, Sally-Anne; Edwards, Grant A.; Madden, Peter W.

2013-01-01

We have compared the effects of different sterilization techniques on the properties of Bombyx mori silk fibroin thin films with the view to subsequent use for corneal tissue engineering. The transparency, tensile properties, corneal epithelial cell attachment and degradation of the films were used to evaluate the suitability of certain sterilization techniques including gamma-irradiation (in air or nitrogen), steam treatment and immersion in aqueous ethanol. The investigations showed that gamma-irradiation, performed either in air or in a nitrogen atmosphere, did not significantly alter the properties of films. The films sterilized by gamma-irradiation or by immersion in ethanol had a transparency greater than 98% and tensile properties comparable to human cornea and amniotic membrane, the materials of choice in the reconstruction of ocular surface. Although steam-sterilization produced stronger, stiffer films, they were less transparent, and cell attachment was affected by the variable topography of these films. It was concluded that gamma-irradiation should be considered to be the most suitable method for the sterilization of silk fibroin films, however, the treatment with ethanol is also an acceptable method. - Highlights: ► The effects of four methods of sterilization on the properties of silk fibroin films were investigated. ► Steam treatment leads to stiffer films but to lower transparency and variable surface topography. ► Degradation of fibroin is enhanced in the films that were gamma-irradiated. ► The effects on mechanical properties are explained through changes in both primary and secondary structure of fibroin. ► Gamma-irradiation and immersion in aqueous ethanol are suggested as preferred methods of sterilization.

MICROSTRUCTURAL PARAMETERS IN 8 MeV ELECTRON‐IRRADIATED BOMBYX MORI SILK FIBERS BY Wide‐ANGLE X‐RAY SCATTERING STUDIES (WAXS)

Energy Technology Data Exchange (ETDEWEB)

Sangappa,, E-mail: sangappa@mangaloreuniversity.ac.in; Asha, S, E-mail: sangappa@mangaloreuniversity.ac.in [Department of Studies in Physics, Mangalore University, Mangalagangotri‐574 199 (India); Sanjeev, Ganesh, E-mail: sangappa@mangaloreuniversity.ac.in [Microtron Center, Mangalore University, Mangalagangotri‐574 199 (India); Subramanya, G, E-mail: sangappa@mangaloreuniversity.ac.in [Department of Studies in Sericulture, University of Mysore, Manasagangotri, Mysore‐570 006 (India); Parameswara, P, E-mail: sangappa@mangaloreuniversity.ac.in; Somashekar, R, E-mail: sangappa@mangaloreuniversity.ac.in [Department of Studies in Physics, University of Mysore, Manasagangotri, Mysore‐570 006 (India)

2010-01-05

The present work looks into the microstructural modification in electron irradiated Bombyx mori P31 silk fibers. The irradiation process was performed in air at room temperature using 8 MeV electron accelerator at different doses: 0, 25, 50 and 100 kGy. Irradiation of polymer is used to cross‐link or degrade the desired component or to fix the polymer morphology. The changes in microstructural parameters in these natural polymer fibers have been computed using wide angle X‐ray scattering (WAXS) data and employing line profile analysis (LPA) using Fourier transform technique of Warren. Exponential, Lognormal and Reinhold functions for the column length distributions have been used for the determination of crystal size, lattice strain and enthalpy parameters.

Microstructural Parameters in 8 MeV Electron-Irradiated BOMBYX MORI Silk Fibers by Wide-ANGLE X-Ray Scattering Studies (waxs)

Science.gov (United States)

Sangappa, Asha, S.; Sanjeev, Ganesh; Subramanya, G.; Parameswara, P.; Somashekar, R.

2010-01-01

The present work looks into the microstructural modification in electron irradiated Bombyx mori P31 silk fibers. The irradiation process was performed in air at room temperature using 8 MeV electron accelerator at different doses: 0, 25, 50 and 100 kGy. Irradiation of polymer is used to cross-link or degrade the desired component or to fix the polymer morphology. The changes in microstructural parameters in these natural polymer fibers have been computed using wide angle X-ray scattering (WAXS) data and employing line profile analysis (LPA) using Fourier transform technique of Warren. Exponential, Lognormal and Reinhold functions for the column length distributions have been used for the determination of crystal size, lattice strain and enthalpy parameters.

MICROSTRUCTURAL PARAMETERS IN 8 MeV ELECTRON‐IRRADIATED BOMBYX MORI SILK FIBERS BY Wide‐ANGLE X‐RAY SCATTERING STUDIES (WAXS)

International Nuclear Information System (INIS)

Sangappa,; Asha, S; Sanjeev, Ganesh; Subramanya, G; Parameswara, P; Somashekar, R

2010-01-01

The present work looks into the microstructural modification in electron irradiated Bombyx mori P31 silk fibers. The irradiation process was performed in air at room temperature using 8 MeV electron accelerator at different doses: 0, 25, 50 and 100 kGy. Irradiation of polymer is used to cross‐link or degrade the desired component or to fix the polymer morphology. The changes in microstructural parameters in these natural polymer fibers have been computed using wide angle X‐ray scattering (WAXS) data and employing line profile analysis (LPA) using Fourier transform technique of Warren. Exponential, Lognormal and Reinhold functions for the column length distributions have been used for the determination of crystal size, lattice strain and enthalpy parameters.

Can the silkworm (Bombyx mori) be used as a human disease model?

Science.gov (United States)

Tabunoki, Hiroko; Bono, Hidemasa; Ito, Katsuhiko; Yokoyama, Takeshi

2016-02-01

Bombyx mori (silkworm) is the most famous lepidopteran in Japan. B. mori has long been used in the silk industry and also as a model insect for agricultural research. In recent years, B. mori has attracted interest in its potential for use in pathological analysis of model animals. For example, the human macular carotenoid transporter was discovered using information of B. mori carotenoid transporter derived from yellow-cocoon strain. The B. mori carotenoid transport system is useful in human studies. To develop a human disease model, we characterized the human homologs of B. mori, and by constructing KAIKO functional annotation pipeline, and to analyze gene expression profile of a unique B. mori mutant strain using microarray analysis. As a result, we identified a novel molecular network involved in Parkinson's disease. Here we describe the potential use of a spontaneous mutant silkworm strain as a human disease model. We also summarize recent progress in the application of genomic information for annotation of human homologs in B. mori. The B. mori mutant will provide a clue to pathological mechanisms, and the findings will be helpful for the development of therapies and for medical drug discovery.

Anatomical and functional analysis of domestication effects on the olfactory system of the silkmoth Bombyx mori.

Science.gov (United States)

Bisch-Knaden, Sonja; Daimon, Takaaki; Shimada, Toru; Hansson, Bill S; Sachse, Silke

2014-01-07

The silkmoth Bombyx mori is the main producer of silk worldwide and has furthermore become a model organism in biological research, especially concerning chemical communication. However, the impact domestication might have had on the silkmoth's olfactory sense has not yet been investigated. Here, we show that the pheromone detection system in B. mori males when compared with their wild ancestors Bombyx mandarina seems to have been preserved, while the perception of environmental odorants in both sexes of domesticated silkmoths has been degraded. In females, this physiological impairment was mirrored by a clear reduction in olfactory sensillum numbers. Neurophysiological experiments with hybrids between wild and domesticated silkmoths suggest that the female W sex chromosome, so far known to have the sole function of determining femaleness, might be involved in the detection of environmental odorants. Moreover, the coding of odorants in the brain, which is usually similar among closely related moths, differs strikingly between B. mori and B. mandarina females. These results indicate that domestication has had a strong impact on odour detection and processing in the olfactory model species B. mori.

Characterization of water in hydrated Bombyx mori silk fibroin fiber and films by 2H NMR relaxation and 13C solid state NMR.

Science.gov (United States)

Asakura, Tetsuo; Isobe, Kotaro; Kametani, Shunsuke; Ukpebor, Obehi T; Silverstein, Moshe C; Boutis, Gregory S

2017-03-01

The mechanical properties of Bombyx mori silk fibroin (SF), such as elasticity and tensile strength, change remarkably upon hydration. However, the microscopic interaction with water is not currently well understood on a molecular level. In this work, the dynamics of water molecules interacting with SF was studied by 2 H solution NMR relaxation and exchange measurements. Additionally, the conformations of hydrated [3- 13 C]Ala-, [3- 13 C]Ser-, and [3- 13 C]Tyr-SF fibers and films were investigated by 13 C DD/MAS NMR. Using an inverse Laplace transform algorithm, we were able to identify four distinct components in the relaxation times for water in SF fiber. Namely, A: bulk water outside the fiber, B: water molecules trapped weakly on the surface of the fiber, C: bound water molecules located in the inner surface of the fiber, and D: bound water molecules located in the inner part of the fiber were distinguishable. In addition, four components were also observed for water in the SF film immersed in methanol for 30s, while only two components for the film immersed in methanol for 24h. The effects of hydration on the conformation of Ser and Tyr residues in the site-specific crystalline and non-crystalline domains of 13 C selectively labeled SF, respectively, could be determined independently. Our measurements provide new insight relating the characteristics of water and the hydration structure of silk, which are relevant in light of current interest in the design of novel silk-based biomaterials. The mechanical properties of Bombyx mori silk fibroin (SF) change remarkably upon hydration. However, the microscopic interaction between SF and water is not currently well understood on a molecular level. We were able to identify four distinct components in the relaxation times for water in SF fiber by 2 H solution NMR relaxation and exchange measurements. In addition, the effects of hydration on the conformation of Ser and Tyr residues in the site-specific crystalline and

Genome-wide identification, characterization of sugar transporter genes in the silkworm Bombyx mori and role in Bombyx mori nucleopolyhedrovirus (BmNPV) infection.

Science.gov (United States)

Govindaraj, Lekha; Gupta, Tania; Esvaran, Vijaya Gowri; Awasthi, Arvind Kumar; Ponnuvel, Kangayam M

2016-04-01

Sugar transporters play an essential role in controlling carbohydrate transport and are responsible for mediating the movement of sugars into cells. These genes exist as large multigene families within the insect genome. In insects, sugar transporters not only have a role in sugar transport, but may also act as receptors for virus entry. Genome-wide annotation of silkworm Bombyx mori (B. mori) revealed 100 putative sugar transporter (BmST) genes exists as a large multigene family and were classified into 11 sub families, through phylogenetic analysis. Chromosomes 27, 26 and 20 were found to possess the highest number of BmST paralogous genes, harboring 22, 7 and 6 genes, respectively. These genes occurred in clusters exhibiting the phenomenon of tandem gene duplication. The ovary, silk gland, hemocytes, midgut and malphigian tubules were the different tissues/cells enriched with BmST gene expression. The BmST gene BGIBMGA001498 had maximum EST transcripts of 134 and expressed exclusively in the malphigian tubule. The expression of EST transcripts of the BmST clustered genes on chromosome 27 was distributed in various tissues like testis, ovary, silk gland, malphigian tubule, maxillary galea, prothoracic gland, epidermis, fat body and midgut. Three sugar transporter genes (BmST) were constitutively expressed in the susceptible race and were down regulated upon BmNPV infection at 12h post infection (hpi). The expression pattern of these three genes was validated through real-time PCR in the midgut tissues at different time intervals from 0 to 30hpi. In the susceptible B. mori race, expression of sugar transporter genes was constitutively expressed making the host succumb to viral infection. Copyright © 2015 Elsevier B.V. All rights reserved.

Surface display and bioactivity of Bombyx mori acetylcholinesterase on Pichia pastoris

Science.gov (United States)

To construct the Pichia pastoris (P. pastoris) cell surface display system of Bombyx mori acetylcholinesterase (BmAChE), the gene for the anchor protein (AGa1) was obtained from Saccharomyces cerevisiae and was fused with the modified Bombyx mori acetylcholinesterase gene (bmace) and transformed int...

Effects of Titanium Dioxide Nanoparticles on the Synthesis of Fibroin in Silkworm (Bombyx mori).

Science.gov (United States)

Ni, Min; Li, FanChi; Tian, JiangHai; Hu, JingSheng; Zhang, Hua; Xu, KaiZun; Wang, BinBin; Li, YangYang; Shen, WeiDe; Li, Bing

2015-08-01

Silkworm (Bombyx mori) is an economically important insect, and its silk production capacity largely depends on its ability to synthesize fibroin. While breeding of B. mori varieties has been a key strategy to improve silk production, little improvement of B. mori silk production has been achieved to date. As a result, the development of sericulture economy has not progressed well, pointing to the need of new ways for improvement of B. mori silk production. Titanium dioxide nanoparticles (TiO2 NPs), a food additive widely used for livestock, have been shown to promote animal growth and increase the protein synthesis in animals. However, no studies on effect of TiO2 NPs on fibroin synthesis in B. mori have been available. In this study, the differential expression profiles of genes and proteins in the silk gland of B. mori fed without or with TiO2 NPs (5 μg ml(-1)) were analyzed and compared using digital gene expression (DGE), reverse transcription quantitative polymerase chain reaction (RT-qPCR), semi-qPCR, and Western blot analysis. The effects of TiO2 NPs feeding on the activity of proteases in the midgut and the synthesis and transportation of amino acids in hemolymph were also investigated. DGE analyses showed that among a total of 4,741 genes detected, 306 genes were differentially expressed after the TiO2 NPs feeding, of which 137 genes were upregulated whereas 169 genes were downregulated. 106 genes were shown to be involved in fibroin synthesis, of which 97 genes, including those encoding cuticular protein glycine-rich 10, serine protease inhibitor 28, aspartate aminotransferase, lysyl-tRNA synthetase, and splicing factor arginine/serine-rich 6, and silk gland factor-1 (SGF-1), were upregulated with the maximum induction of 8.52-folds, whereas nine genes, including those encoding aspartylglucosaminidase, the cathepsin L in Tribolium castaneum, and similar to SPRY domain-containing SOCS box protein 3, were downregulated with the maximum reduction of 8

Sample selection, preparation methods, and the apparent tensile properties of silkworm (B. mori) cocoon silk.

Science.gov (United States)

Reed, Emily J; Bianchini, Lindsay L; Viney, Christopher

2012-06-01

Reported literature values of the tensile properties of natural silk cover a wide range. While much of this inconsistency is the result of variability that is intrinsic to silk, some is also a consequence of differences in the way that silk is prepared for tensile tests. Here we explore how measured mechanical properties of Bombyx mori cocoon silk are affected by two intrinsic factors (the location from which the silk is collected within the cocoon, and the color of the silk), and two extrinsic factors (the storage conditions prior to testing, and different styles of reeling the fiber). We find that extrinsic and therefore controllable factors can affect the properties more than the intrinsic ones studied. Our results suggest that enhanced inter-laboratory collaborations, that lead to standardized sample collection, handling, and storage protocols prior to mechanical testing, would help to decrease unnecessary (and complicating) variation in reported tensile properties. Copyright © 2011 Wiley Periodicals, Inc.

Direct and indirect effects of RNA interference against pyridoxal kinase and pyridoxine 5'-phosphate oxidase genes in Bombyx mori.

Science.gov (United States)

Huang, ShuoHao; Yao, LiLi; Zhang, JianYun; Huang, LongQuan

2016-08-01

Vitamin B6 comprises six interconvertible pyridine compounds (vitamers), among which pyridoxal 5'-phosphate is a coenzyme involved in a high diversity of biochemical reactions. Humans and animals obtain B6 vitamers from diet, and synthesize pyridoxal 5'-phosphate by pyridoxal kinase and pyridoxine 5'-phosphate oxidase. Currently, little is known on how pyridoxal 5'-phosphate biosynthesis is regulated, and pyridoxal 5'-phosphate is supplied to meet their requirement in terms of cofactor. Bombyx mori is a large silk-secreting insect, in which protein metabolism is most active, and the vitamin B6 demand is high. In this study, we successfully down-regulated the gene expression of pyridoxal kinase and pyridoxine 5'-phosphate oxidase by body cavity injection of synthesized double-stranded small interfering RNA to 5th instar larvae of Bombyx mori, and analyzed the gene transcription levels of pyridoxal 5'-phosphate dependent enzymes, phosphoserine aminotransferase and glutamic-oxaloacetic transaminase. Results show that the gene expression of pyridoxal kinase and pyridoxine 5'-phosphate oxidase has a greater impact on the gene transcription of enzymes using pyridoxal 5'-phosphate as a cofactor in Bombyx mori. Our study suggests that pyridoxal 5'-phosphate biosynthesis and dynamic balance may be regulated by genetic networks. Copyright © 2016 Elsevier B.V. All rights reserved.

Quantitative phosphoproteome on the silkworm (Bombyx mori) cells infected with baculovirus.

Science.gov (United States)

Shobahah, Jauharotus; Xue, Shengjie; Hu, Dongbing; Zhao, Cui; Wei, Ming; Quan, Yanping; Yu, Wei

2017-06-19

Bombyx mori has become an important model organism for many fundamental studies. Bombyx mori nucleopolyhedrovirus (BmNPV) is a significant pathogen to Bombyx mori, yet also an efficient vector for recombinant protein production. A previous study indicated that acetylation plays many vital roles in several cellular processes of Bombyx mori while global phosphorylation pattern upon BmNPV infection remains elusive. Employing tandem mass tag (TMT) labeling and phosphorylation affinity enrichment followed by high-resolution LC-MS/MS analysis and intensive bioinformatics analysis, the quantitative phosphoproteome in Bombyx mori cells infected by BmNPV at 24 hpi with an MOI of 10 was extensively examined. Totally, 6480 phosphorylation sites in 2112 protein groups were identified, among which 4764 sites in 1717 proteins were quantified. Among the quantified proteins, 81 up-regulated and 25 down-regulated sites were identified with significant criteria (the quantitative ratio above 1.3 was considered as up-regulation and below 0.77 was considered as down-regulation) and with significant p-value (p < 0.05). Some proteins of BmNPV were also hyperphosphorylated during infection, such as P6.9, 39 K, LEF-6, Ac58-like protein, Ac82-like protein and BRO-D. The phosphorylated proteins were primary involved in several specific functions, out of which, we focused on the binding activity, protein synthesis, viral replication and apoptosis through kinase activity.

Identification of Sumoylated Proteins in the Silkworm Bombyx mori

Science.gov (United States)

Tang, Xudong; Fu, Xuliang; Hao, Bifang; Zhu, Feng; Xiao, Shengyan; Xu, Li; Shen, Zhongyuan

2014-01-01

Small ubiquitin-like modifier (SUMO) modification (SUMOylation) is an important and widely used reversible modification system in eukaryotic cells. It regulates various cell processes, including protein targeting, transcriptional regulation, signal transduction, and cell division. To understand its role in the model lepidoptera insect Bombyx mori, a recombinant baculovirus was constructed to express an enhanced green fluorescent protein (eGFP)-SUMO fusion protein along with ubiquitin carrier protein 9 of Bombyx mori (BmUBC9). SUMOylation substrates from Bombyx mori cells infected with this baculovirus were isolated by immunoprecipitation and identified by LC–ESI-MS/MS. A total of 68 candidate SUMOylated proteins were identified, of which 59 proteins were functionally categorized to gene ontology (GO) terms. Analysis of kyoto encyclopedia of genes and genomes (KEGG) pathways showed that 46 of the identified proteins were involved in 76 pathways that mainly play a role in metabolism, spliceosome and ribosome functions, and in RNA transport. Furthermore, SUMOylation of four candidates (polyubiquitin-C-like isoform X1, 3-hydroxyacyl-CoA dehydrogenase, cyclin-related protein FAM58A-like and GTP-binding nuclear protein Ran) were verified by co-immunoprecipitation in Drosophila schneide 2 cells. In addition, 74% of the identified proteins were predicted to have at least one SUMOylation site. The data presented here shed light on the crucial process of protein sumoylation in Bombyx mori. PMID:25470021

Silkworm Gut Fiber of Bombyx mori as an Implantable and Biocompatible Light-Diffusing Fiber

Directory of Open Access Journals (Sweden)

Jose Luis Cenis

2016-07-01

Full Text Available This work describes a new approach to the delivery of light in deeper tissues, through a silk filament that is implantable, biocompatible, and biodegradable. In the present work, silkworm gut fibers (SGFs of Bombyx mori L., are made by stretching the silk glands. Morphological, structural, and optical properties of the fibers have been characterized and the stimulatory effect of red laser light diffused from the fiber was assayed in fibroblast cultures. SGFs are formed by silk fibroin (SF mainly in a β-sheet conformation, a stable and non-soluble state in water or biological fluids. The fibers showed a high degree of transparency to visible and infrared radiation. Using a red laser (λ = 650 nm as source, the light was efficiently diffused along the fiber wall, promoting a significant increment in the cell metabolism 5 h after the irradiation. SGFs have shown their excellent properties as light-diffusing optical fibers with a stimulatory effect on cells.

The genomic underpinnings of apoptosis in the silkworm, Bombyx mori

Science.gov (United States)

2010-01-01

Background Apoptosis is regulated in an orderly fashion by a series of genes, and has a crucial role in important physiological processes such as growth development, immunological response and so on. Recently, substantial studies have been undertaken on apoptosis in model animals including humans, fruit flies, and the nematode. However, the lack of genomic data for silkworms limits their usefulness in apoptosis studies, despite the advantages of silkworm as a representative of Lepidoptera and an effective model system. Herein we have identified apoptosis-related genes in the silkworm Bombyx mori and compared them to those from insects, mammals, and nematodes. Results From the newly assembled genome databases, a genome-wide analysis of apoptosis-related genes in Bombyx mori was performed using both nucleotide and protein Blast searches. Fifty-two apoptosis-related candidate genes were identified, including five caspase family members, two tumor necrosis factor (TNF) superfamily members, one Bcl-2 family member, four baculovirus IAP (inhibitor of apoptosis) repeat (BIR) domain family members and 1 RHG (Reaper, Hid, Grim, and Sickle; Drosophila cell death activators) family member. Moreover, we identified a new caspase family member, BmCaspase-New, two splice variants of BmDronc, and Bm3585, a mammalian TNF superfamily member homolog. Twenty-three of these apoptosis-related genes were cloned and sequenced using cDNA templates isolated from BmE-SWU1 cells. Sequence analyses revealed that these genes could have key roles in apoptosis. Conclusions Bombyx mori possesses potential apoptosis-related genes. We hypothesized that the classic intrinsic and extrinsic apoptotic pathways potentially are active in Bombyx mori. These results lay the foundation for further apoptosis-related study in Bombyx mori. PMID:21040523

Basic Helix-Loop-Helix Transcription Factor Bmsage Is Involved in Regulation of fibroin H-chain Gene via Interaction with SGF1 in Bombyx mori

Science.gov (United States)

Li, Qiong-Yan; Hu, Wen-Bo; Zhou, Meng-Ting; Nie, Hong-Yi; Zhang, Yin-Xia; Peng, Zhang-Chuan; Zhao, Ping; Xia, Qing-You

2014-01-01

Silk glands are specialized in the synthesis of several secretory proteins. Expression of genes encoding the silk proteins in Bombyx mori silk glands with strict territorial and developmental specificities is regulated by many transcription factors. In this study, we have characterized B. mori sage, which is closely related to sage in the fruitfly Drosophila melanogaster. It is termed Bmsage; it encodes transcription factor Bmsage, which belongs to the Mesp subfamily, containing a basic helix–loop–helix motif. Bmsage transcripts were detected specifically in the silk glands of B. mori larvae through RT-PCR analysis. Immunoblotting analysis confirmed the Bmsage protein existed exclusively in B. mori middle and posterior silk gland cells. Bmsage has a low level of expression in the 4th instar molting stages, which increases gradually in the 5th instar feeding stages and then declines from the wandering to the pupation stages. Quantitative PCR analysis suggested the expression level of Bmsage in a high silk strain was higher compared to a lower silk strain on day 3 of the larval 5th instar. Furthermore, far western blotting and co-immunoprecipitation assays showed the Bmsage protein interacted with the fork head transcription factor silk gland factor 1 (SGF1). An electrophoretic mobility shift assay showed the complex of Bmsage and SGF1 proteins bound to the A and B elements in the promoter of fibroin H-chain gene(fib-H), respectively. Luciferase reporter gene assays confirmed the complex of Bmsage and SGF1 proteins increased the expression of fib-H. Together, these results suggest Bmsage is involved in the regulation of the expression of fib-H by being together with SGF1 in B. mori PSG cells. PMID:24740008

Thymosin From Bombyx mori Is Down-Regulated in Expression by BmNPV Exhibiting Antiviral Activity.

Science.gov (United States)

Zhang, Chen; Wang, Yongdi; Fang, Qiang; Xu, Minlin; Lv, Mengyuan; Liao, Jinxu; Li, Si; Nie, Zuoming; Zhang, Wenping

2016-01-01

Thymosins have been highly conserved during evolution. These hormones exist in many animal species and play an essential role in many biological events. However, little is known regarding the physiological function of silkworm Bombyx mori thymosin (BmTHY). In this study, we investigated the expression pattern of BmTHY in a Bombyx mori larval ovarian cell line (BmN) challenged with Bombyx mori nuclear polyhydrosis virus (BmNPV) and the antiviral effect of recombinant BmTHY (rBmTHY) for Bombyx mori against BmNPV. Western-blot assay and qRT-PCR analysis revealed that the level of BmTHY protein expression and transcription decreased over time when BmN cells were infected by BmNPV. Treatment with endotoxin-free rBmTHY led to a significant reduction in viral titer in the supernatant of BmN cells challenged with BmNPV. The results from antiviral tests performed in vitro and in vivo showed that endotoxin-free rBmTHY improved the survival rate of Bombyx mori infected with BmNPV. These findings suggest that BmTHY exerts immunomodulatory effects on Bombyx mori, rendering them resistant to viral infection. © The Authors 2016. Published by Oxford University Press on behalf of Entomological Society of America.

In vivo NMR analysis of incorporation of [2-13C] glycine into silk fibroin

International Nuclear Information System (INIS)

Asakura, Tetsuo; Nagashima, Mariko; Demura, Makoto; Osanai, Minoru.

1990-01-01

The biosynthetic mechanism of silk fibroin in silkworms, Bombyx mori, is unique because this fibrous protein composed mainly of glycine, alanine and serine is produced very rapidly in large quantity in the posterior silk glands. It is very meaningful to investigate into the biosynthesis of silk protein under nondestructive condition by in vivo NMR and C-13 labeling techniques. The sugar metabolism related to the production of silk fibroin was analyzed by monitoring the change in the C-13 labeled peaks in the NMR spectra for silkworms. In this paper, the monitoring of the 2-(C-13) glycine metabolism in Bombyx mori by the C-13 NMR in vivo is reported. In particular, the in vivo transport of glycine from the midgut to the posterior silk gland was measured, and the rate constants were determined with the course of the peak intensity in the C-13 NMR spectra. It is possible to discuss quantitatively the in vivo production of silk fibroin with these rate constants. The experiment and the results are reported. The in vivo C-13 NMR spectra of a 5 day old, 5th instar larva of Bombyx mori after the oral administration of 2-(C-13) glycine are shown. The significant increase of the peak intensity occurred. (K.I.)

Fibroin and sericin from Bombyx mori silk stimulate cell migration through upregulation and phosphorylation of c-Jun.

Directory of Open Access Journals (Sweden)

Celia Martínez-Mora

Full Text Available Wound healing is a biological process directed to the restoration of tissue that has suffered an injury. An important phase of wound healing is the generation of a basal epithelium able to wholly replace the epidermis of the wound. A broad range of products derived from fibroin and sericin from Bombyx mori silk are used to stimulate wound healing. However, so far the molecular mechanism underlying this phenomenon has not been elucidated. The aim of this work was to determine the molecular basis underlying wound healing properties of silk proteins using a cell model. For this purpose, we assayed fibroin and sericin in a wound healing scratch assay using MDA-MB-231 and Mv1Lu cells. Both proteins stimulated cell migration. Furthermore, treatment with sericin and fibroin involved key factors of the wound healing process such as upregulation of c-Jun and c-Jun protein phosphorylation. Moreover, fibroin and sericin stimulated the phosphorylation of ERK 1/2 and JNK 1/2 kinases. All these experiments were done in the presence of specific inhibitors for some of the cell signalling pathways referred above. The obtained results revealed that MEK, JNK and PI3K pathways are involved in fibroin and sericin stimulated cells migration. Inhibition of these three kinases prevented c-Jun upregulation and phosphorylation by fibroin or sericin. Fibroin and sericin were tested in the human keratinocyte cell line, HaCaT, with similar results. Altogether, our results showed that fibroin and sericin initiate cell migration by activating the MEK, JNK and PI3K signalling pathways ending in c-Jun activation.

Microstructural parameters in 8 MeV Electron irradiated Bombyx mori silk fibers by wide-angle X-ray scattering studies (WAXS)

International Nuclear Information System (INIS)

Halabhavi, Sangappa

2009-01-01

The present work looks into the microstructural modification in Bombyx mori silk fibers, induced by electron irradiation. The irradiation process was performed in air at room temperature by use of 8 MeV electron accelerators at different doses: 0, 25, 50, 75 and 100 kGy respectively. Irradiation of polymer can be used to crosslink or degrade the desired component or to fixate the polymer morphology. The changes in microstructural parameters in these natural polymer fibers have been studied using wide angle X-ray scattering (WAXS) method. The crystal imperfection parameters such as crystallite size , lattice strain (g in %) and enthalpy (a * ) have been determined by line profile analysis (LPA) using Fourier method of Warren. Exponential, Lognormal and Reinhold functions for the column length distributions have been used for the determination of these parameters. The goodness of the fit and the consistency of these results suggest that the exponential distribution gives much better results, even though lognormal distribution has been widely used to estimate the similar stacking faults in metal oxide compounds. (author)

Microwave assisted synthesis of luminescent carbonaceous nanoparticles from silk fibroin for bioimaging.

Science.gov (United States)

Gao, Hongzhi; Teng, Choon Peng; Huang, Donghong; Xu, Wanqing; Zheng, Chaohui; Chen, Yisong; Liu, Minghuan; Yang, Da-Peng; Lin, Ming; Li, Zibiao; Ye, Enyi

2017-11-01

Bombyx mori silk as a natural protein based biopolymer with high nitrogen content, is abundant and sustainable because of its mass product all over the world per year. In this study, we developed a facile and fast microwave-assisted synthesis of luminescent carbonaceous nanoparticles using Bombyx mori silk fibroin and silk solution as the precursors. As a result, the obtained carbonaceous nanoparticles exhibit a photoluminescence quantum yield of ~20%, high stability, low cytotoxicity, high biocompatibility. Most importantly, we successfully demonstrated bioimaging using these luminescent carbonaceous nanoparticles with excitation dependent luminescence. In addition, the microwave-assisted hydrothermal method can be extended to convert other biomass into functional nanomaterials. Copyright © 2017 Elsevier B.V. All rights reserved.

Changes in polyamine levels in various organs of Bombyx mori during its life cycle.

Science.gov (United States)

Hamana, K; Matsuzaki, S; Inoue, K

1984-06-01

Polyamines in various organs of larval, pupal, and moth stages of Bombyx mori, were assayed by high-performance ion-exchange chromatography and paper and thin-layer chromatography. Putrescine and spermidine were especially abundant in the silk gland, gonads, mucous gland, and sucking stomach; spermine was also present in them, but at much lower concentrations. Both norspermidine and norspermine were detected in almost all organs examined, while their precursor 1,3-diaminopropane was found only in a limited number of organs. Low concentrations of sym-homospermidine were observed in the silk gland and ovary. Cadaverine content was particularly high in the mucous gland which contained diapause eggs and the sucking stomach. Diapause eggs contained much higher levels of cadaverine than non-diapause eggs. The concentrations of most polyamines in the silk glands remained rather constant during the larval stage, and decreased markedly at the pupal stage. Polyamines in gonads, in contrast, did not decrease at the pupal stage, but putrescine, diaminopropane, and norspermidine rather increased during the pupal and moth stages.

Biotransformation effect of Bombyx Mori L. may play an important role in treating diabetic nephropathy.

Science.gov (United States)

Zhang, Lei; Zhang, La; Li, Yin; Guo, Xin-Feng; Liu, Xu-Sheng

2016-11-01

Compared with herbal drugs, medicine processed from animals (animal medicine) was thought to have more bioactive substances and higher activities. Biotransformation effect often plays an important role in their effect. However, researches about effect of animal medicine on diabetic nephropathy and applying animal medicine as natural bio-transformer were seldom reported. The purpose of this paper was to reveal the use of Bombyx Mori L. on diabetic nephropathy from ancient to modern times. The classical literature indicated that Saosi Decoction (), which contains Bombyx Mori L. or silkworm cocoon, was applied to treat disorders congruent with modern disease diabetic nephropathy from the Ming to Qing Dynasty in ancient China. Modern studies showed that Bombyx Mori L. contains four main active constituents. Among these, 1-deoxynojirimycin (1-DNJ) and quercetin showed promising potential to be new agents in diabetic nephropathy treatment. The concentrations of 1-DNJ and the activities of quercetin in Bombyx Mori L. are higher than in mulberry leaves, because of the biotransformation in the Bombyx Mori L. body. However, these specifific components need further human and mechanistic studies to determine their therapeutic potential for this challenging condition.

Protective Effect of Bombyx mori L Cocoon (Abresham) and its ...

African Journals Online (AJOL)

HP

Protective Effect of Bombyx mori L Cocoon (Abresham) and its ... agonist, at high doses, has been reported to produce ... 12:12 h. Standard pellet diet and tap water were ... induction of myocardial injury on the scheduled ... Total protein in of B. mori cocoon (Abresham) ..... The authors thank Professor SK Maulik, Head,.

Chitin in the Silk Gland Ducts of the Spider Nephila edulis and the Silkworm Bombyx mori

Science.gov (United States)

Davies, Gwilym J. G.; Knight, David P.; Vollrath, Fritz

2013-01-01

Here we report the detection and localisation of chitin in the cuticle of the spinning ducts of both the spider Nephila edulis and the silkworm Bombyx mori. Our observations demonstrate that the duct walls of both animals contain chitin notwithstanding totally independent evolutionary pathways of the systems. We conclude that chitin may well be an essential component for the construction of spinning ducts; we further conclude that in both species chitin may indicate the evolutionary origin of the spinning ducts. PMID:24015298

SilkDB: a knowledgebase for silkworm biology and genomics

DEFF Research Database (Denmark)

Wang, Jing; Xia, Qingyou; He, Ximiao

2005-01-01

The Silkworm Knowledgebase (SilkDB) is a web-based repository for the curation, integration and study of silkworm genetic and genomic data. With the recent accomplishment of a approximately 6X draft genome sequence of the domestic silkworm (Bombyx mori), SilkDB provides an integrated representati....... SilkDB is publicly accessible at http://silkworm.genomics.org.cn. Udgivelsesdato: 2005-Jan-1...

Horizontal gene transfer in silkworm, Bombyx mori

Science.gov (United States)

2011-01-01

Background The domesticated silkworm, Bombyx mori, is the model insect for the order Lepidoptera, has economically important values, and has gained some representative behavioral characteristics compared to its wild ancestor. The genome of B. mori has been fully sequenced while function analysis of BmChi-h and BmSuc1 genes revealed that horizontal gene transfer (HGT) maybe bestow a clear selective advantage to B. mori. However, the role of HGT in the evolutionary history of B. mori is largely unexplored. In this study, we compare the whole genome of B. mori with those of 382 prokaryotic and eukaryotic species to investigate the potential HGTs. Results Ten candidate HGT events were defined in B. mori by comprehensive sequence analysis using Maximum Likelihood and Bayesian method combining with EST checking. Phylogenetic analysis of the candidate HGT genes suggested that one HGT was plant-to- B. mori transfer while nine were bacteria-to- B. mori transfer. Furthermore, functional analysis based on expression, coexpression and related literature searching revealed that several HGT candidate genes have added important characters, such as resistance to pathogen, to B. mori. Conclusions Results from this study clearly demonstrated that HGTs play an important role in the evolution of B. mori although the number of HGT events in B. mori is in general smaller than those of microbes and other insects. In particular, interdomain HGTs in B. mori may give rise to functional, persistent, and possibly evolutionarily significant new genes. PMID:21595916

Respiratory allergy to moth: the importance of sensitization to Bombyx mori in children with asthma and rhinitis.

Science.gov (United States)

Araujo, Laura M L; Rosário Filho, Nelson A; Riedi, Carlos A

2014-01-01

this study aimed to prepare a silkworm moth (Bombyx mori) antigenic extract and to perform skin prick tests with this extract in patients with allergic respiratory diseases; to evaluate serum specific immunoglobulin E (IgE) to Bombyx mori using ImmunoCAP® system and to report the frequency of positivity between the two methods and with clinical data. this was a cross-sectional study with 99 children and adolescents diagnosed with asthma and/or allergic rhinitis, who had skin reactivity to at least one of the six aeroallergens tested. Clinical data were evaluated: skin prick tests with Bombyx mori in-house extract, and total and specific IgE analysis using ImmunoCAP® were performed. the frequency of Bombyx mori specific IgE was found to be 52.5% and 60% using the skin prick test and ImmunoCAP®, respectively. An association between a positive skin test for Bombyx mori and the presence of allergic rhinitis, atopic dermatitis, and urticaria was observed, but the same was not true for asthma or allergic conjunctivitis. There was no relation with the severity of asthma or rhinitis symptoms. a high frequency of sensitization to Bombyx mori was observed in a selected population of patients with respiratory allergic diseases in the city of Curitiba, state of Paraná, Brazil. The extract prepared from the wings of this moth species is effective in demonstrating this sensitivity. Copyright © 2013 Sociedade Brasileira de Pediatria. Published by Elsevier Editora Ltda. All rights reserved.

The effect of thyroxine on silk gland and the effect of two thyroxine ...

African Journals Online (AJOL)

The influence of feeding mulberry leaves treated with thyroxine to the growth of the silk gland, and the effect of two different mulberry species, that is, Morus nigra and Morus multicaulis treated with thyroxine on silk quality in the silkworm were studied. The silk glands from thyroxine treated Bombyx mori larvae weighed ...

20-Hydroxyecdysone stimulates nuclear accumulation of BmNep1, a nuclear ribosome biogenesis-related protein in the silkworm, Bombyx mori.

Science.gov (United States)

Ji, M-M; Liu, A-Q; Sima, Y-H; Xu, S-Q

2016-10-01

The pathway of communication between endocrine hormones and ribosome biogenesis critical for physiological adaptation is largely unknown. Nucleolar essential protein 1 (Nep1) is an essential gene for ribosome biogenesis and is functionally conserved in many in vertebrate and invertebrate species. In this study, we cloned Bombyx mori Nep1 (BmNep1) due to its high expression in silk glands of silkworms on day 3 of the fifth instar. We found that BmNep1 mRNA and protein levels were upregulated in silk glands during fourth-instar ecdysis and larval-pupal metamorphosis. By immunoprecipitation with the anti-BmNep1 antibody and liquid chromatography-tandem mass spectrometry analyses, it was shown that BmNep1 probably interacts with proteins related to ribosome structure formation. Immunohistochemistry, biochemical fractionation and immunocytochemistry revealed that BmNep1 is localized to the nuclei in Bombyx cells. Using BmN cells originally derived from ovaries, we demonstrated that 20-hydroxyecdysone (20E) induced BmNep1 expression and stimulated nuclear accumulation of BmNep1. Under physiological conditions, BmNep1 was also upregulated in ovaries during larval-pupal metamorphosis. Overall, our results indicate that the endocrine hormone 20E facilitates nuclear accumulation of BmNep1, which is involved in nuclear ribosome biogenesis in Bombyx. © 2016 The Royal Entomological Society.

Identification and Characterization of 30 K Protein Genes Found in Bombyx mori (Lepidoptera: Bombycidae) Transcriptome

Science.gov (United States)

Shi, Xiao-Feng; Li, Yi-Nü; Yi, Yong-Zhu; Xiao, Xing-Guo; Zhang, Zhi-Fang

2015-01-01

The 30 K proteins, the major group of hemolymph proteins in the silkworm, Bombyx mori (Lepidoptera: Bombycidae), are structurally related with molecular masses of ∼30 kDa and are involved in various physiological processes, e.g., energy storage, embryonic development, and immune responses. For this report, known 30 K protein gene sequences were used as Blastn queries against sequences in the B. mori transcriptome (SilkTransDB). Twenty-nine cDNAs (Bm30K-1–29) were retrieved, including four being previously unidentified in the Lipoprotein_11 family. The genomic structures of the 29 genes were analyzed and they were mapped to their corresponding chromosomes. Furthermore, phylogenetic analysis revealed that the 29 genes encode three types of 30 K proteins. The members increased in each type is mainly a result of gene duplication with the appearance of each type preceding the differentiation of each species included in the tree. Real-Time Quantitative Polymerase Chain Reaction (Q-PCR) confirmed that the genes could be expressed, and that the three types have different temporal expression patterns. Proteins from the hemolymph was separated by SDS-PAGE, and those with molecular mass of ∼30 kDa were isolated and identified by mass spectrometry sequencing in combination with searches of various databases containing B. mori 30K protein sequences. Of the 34 proteins identified, 13 are members of the 30 K protein family, with one that had not been found in the SilkTransDB, although it had been found in the B. mori genome. Taken together, our results indicate that the 30 K protein family contains many members with various functions. Other methods will be required to find more members of the family. PMID:26078299

Analysis of tissue-specific region in sericin 1 gene promoter of Bombyx mori

Energy Technology Data Exchange (ETDEWEB)

Yan, Liu [College of Biomedical Engineering and Instrument Science, Zhejiang University, Hangzhou 310027 (China); Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031 (China); Lian, Yu [College of Biomedical Engineering and Instrument Science, Zhejiang University, Hangzhou 310027 (China); Zhejiang Province Key Laboratory of Preventive Veterinary Medicine, Institute of Preventive Veterinary Medicine, Zhejiang University, Hangzhou 310029 (China); Xiuyang, Guo [Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031 (China); Tingqing, Guo [Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031 (China); Shengpeng, Wang [Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031 (China); Changde, Lu [Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031 (China)

2006-03-31

The gene encoding sericin 1 (Ser1) of silkworm (Bombyx mori) is specifically expressed in the middle silk gland cells. To identify element involved in this transcription-dependent spatial restriction, truncation of the 5' terminal from the sericin 1 (Ser1) promoter is studied in vivo. A 209 bp DNA sequence upstream of the transcriptional start site (-586 to -378) is found to be responsible for promoting tissue-specific transcription. Analysis of this 209 bp region by overlapping deletion studies showed that a 25 bp region (-500 to -476) suppresses the ectopic expression of the Ser1 promoter. An unknown factor abundant in fat body nuclear extracts is shown to bind to this 25 bp fragment. These results suggest that this 25 bp region and the unknown factor are necessary for determining the tissue-specificity of the Ser1 promoter.

Radiosensitivity of Bombyx mori embryos and its modification by thermal shock

International Nuclear Information System (INIS)

Agaev, F.A.; Zakrzhevskaya, D.T.; Yusifov, N.I.; Gaziev, A.I.; AN Azerbajdzhanskoj SSR, Baku

1991-01-01

Radiosensitivity of Bombyx mori embryos on days 3-4 of their development is more than 10 times higher than that of 7-9 day embryos. The rate of DNA synthesis in the embryos correlates with their radiosensitivity. Heat treatment (40 deg C, 60 min) of embryos just before γ-irradiation increases their radioresistance (DMF=+1.6), whereas such a treatment immediately after irradiation reduces the survival rate of embryos as compared to the controls irradiated without heat treatment (DMA=-1.5). The radiomodifying effect of the thermal shock on the Bombyx mori embryos is the same with exposure at both the radioresistant and the radiosensitive stage of their development. However, it is more pronounced at the radiosensitive stage

Bombyx mori cecropin A has a high antifungal activity to entomopathogenic fungus Beauveria bassiana.

Science.gov (United States)

Lu, Dingding; Geng, Tao; Hou, Chengxiang; Huang, Yuxia; Qin, Guangxing; Guo, Xijie

2016-05-25

A cDNA encoding cecropin A (CecA) was cloned from the larvae of silkworm, Bombyx mori, using RT-PCR. It encodes a protein of 63 amino acids, containing a 22 amino acid signal peptide and a 37 amino acid mat peptide of functional domain. The CecA secondary structure contains two typical amphiphilic α-helices. Real-time qPCR analysis revealed that CecA was expressed in all the tissues tested, including cuticle, fat body, hemocytes, Malpighian tubule, midgut and silk gland in the silkworm larvae with the highest expression in the fat body and hemocytes. The gene expression of B. mori CecA was rapidly induced by Beauveria bassiana challenge and reached maximum levels at 36h after inoculation in third instar larvae. In the fifth instar larvae infected with B. bassiana, the relative expression level of CecA was upregulated in fat body and hemocytes, but not in cuticle, Malpighian tubule, midgut and silk gland. The cDNA segment of the CecA was inserted into the expression plasmid pET-30a(+) to construct a recombinant expression plasmid. Western blot results revealed that his-tagged fusion protein was successfully expressed and purified. Then the mat peptide of CecA was chemically synthesized with C-terminus amidation for in vivo antifungal assay and purity achieved 93.7%. Mass spectrometry and SDS-PAGE showed its molecular weight to be 4046.95Da. Antifungal assays indicated that the B. mori CecA had a high antifungal activity to entomopathogenic fungus B. bassiana both in vitro and in vivo in the silkworm larvae. This is the first report that the CecA is effective to inhibit B. bassiana inside the body of silkworm. Copyright © 2016 Elsevier B.V. All rights reserved.

Identification and characterization of an arginine kinase as a major allergen from silkworm (Bombyx mori) larvae.

Science.gov (United States)

Liu, Zhigang; Xia, Lixin; Wu, Yulan; Xia, Qingyou; Chen, Jiajie; Roux, Kenneth H

2009-01-01

The silkworm, Bombyx mori, is an important insect in the textile industry and its pupa are used in Chinese cuisine and traditional Chinese medicine. The silk, urine and dander of silkworms is often the cause of allergies in sericulture workers and the pupa has been found to be a food allergen in China. Recent studies have focused on reporting cases of silkworm allergies, but only a few studies have addressed the specific allergens present in the B. mori silkworm. We collected sera from 10 patients with a positive skin prick test to silkworm crude extract (SCE) and analyzed these samples by Western blot and ELISA. The cDNA of arginine kinase from the B. mori silkworm was also cloned and expressed in high yield in Escherichia coli. Allergenicity and cross-allergenicity of the recombinant B. mori arginine kinase (rBmAK) were investigated by ELISA inhibition assay. Collected sera all reacted to a 42-kDa protein in a Western blot with SCE as the antigen. Preincubation of sera with rBmAK eliminated the reactivity of the patients' sera to this 42-kDa band. All patient sera also exhibited positive reactivity to SCE in an ELISA assay. BmAK also demonstrated cross-reactivity with a recombinant AK from cockroach. Arginine kinase from the B. mori silkworm is a major allergen and crossreacts with cockroach AK. Copyright 2009 S. Karger AG, Basel.

The differential expression of BmGlcNAcase2 in strains of Bombyx mori (Lepidoptera: Bombycidae) with different susceptibility to Bombyx mori (Lepidoptera: Bombycidae) nucleopolyhedrovirus infection.

Science.gov (United States)

Hao, Zhu; Quanbing, Ma; Xiaoyong, Liu

2015-01-01

GlcNAcase is a glycosyl hydrolase located in the lysosomes of numerous organisms. Levels of the protein, β-N-acetylglucosaminidase 2 (GlcNAcase2), which is a member of the GlcNAcase family, are different in two strains of the silkworm Bombyx mori that have different resistance to Bombyx mori nucleopolyhedroviruses (BmNPVs). We identified six single-nucleotide differences in the GlcNAcase2 coding sequence between the 306 and NB strains. Five are silent changes, but one is a nonsynonymous mutation. Reverse transcription-polymerase chain reaction analysis showed that GlcNAcase2 mRNA levels in the NB strain were nearly 2.57 times higher compared with those in the 306 strain. In addition, GlcNAcase2 enzyme activity was much higher in the NB strain compared with that in the 306 strain. Together, these results indicate that GlcNAcase2 may be involved in variable BmNPV resistance in B. mori. © The Author 2015. Published by Oxford University Press on behalf of the Entomological Society of America.

The angiotensin-converting enzyme (ACE) gene family of Bombyx mori.

Science.gov (United States)

Yan, Hai-Yan; Mita, Kazuei; Zhao, Xia; Tanaka, Yoshikazu; Moriyama, Minoru; Wang, Huabin; Iwanaga, Masashi; Kawasaki, Hideki

2017-04-15

We previously reported regarding an ecdysone-inducible angiotensin-converting enzyme (ACE) gene. We found another four ACE genes in the Bombyx genome. The present study was undertaken to clarify the evolutionally changed function of the ACE of Bombyx mori. Core regions of deduced amino acid sequences of ACE genes were compared with those of other insect ACE genes. Five Bombyx genes have the conserved Zn 2+ -binding-site motif (HEXXH); however, BmAcer4 has only one and BmAcer3 has no catalytic ligand. BmAcer1 and BmAcer2 were expressed in several organs. BmAcer3 was expressed in testes, and BmAcer4 and BmAcer5 were expressed in compound eyes; however, the transcription levels of these three genes were very low. Quantitative RT-PCR and Western analysis were conducted to determine the tissue distribution and developmental expression of BmAcer1and BmAcer2. Transcripts of BmAcer1 and BmAcer2 were found in the reproductive organs during the larval and pupal stages. BmAcer1 was dominant in fat bodies during the feeding stage and showed high expression in the epidermis, wing discs, and pupal wing tissues after the wandering stage. Its expression patterns in epidermis, wing discs, and wing tissues resembled the hemolymph ecdysteroid titer in the larval and pupal stages. Acer1 was observed in the hemolymph at all stages, appearing to be the source of it are fat bodies, wings, and epidermis, and functioning after being secreted into the hemolymph. BmAcer2 was abundant in the midgut during the feeding stage and after the wandering stage and in silk glands after the pupal stage. We conclude that the evolution of BmAcer occurred through duplication, and, thereafter, functional diversification developed. Copyright © 2017 Elsevier B.V. All rights reserved.

Produção de casulos de Bombyx mori L. alimentados com dietas artificiais e folhas “in natura” de Morus aba L. Production of cocoon of Bombyx mori L. fed on leaves of Morus aba L. and on artificial diets

Directory of Open Access Journals (Sweden)

Adriana Evangelista Rodrigues

2001-05-01

Full Text Available A utilização de dietas artificiais no Japão já é uma realidade, e no Brasil iniciam-se os estudos buscando encontrar um balanceamento que satisfaça as necessidades das larvas do bicho-da-seda, Bombyx mori (Lepidoptera. Desta forma, foram testados dois cultivares de amoreira como ingredientes das dietas, avaliando-se a qualidade do alimento, através do peso médio dos casulos e teor líquido de seda. As larvas foram separadas em parcelas, no início do 1º ínstar, onde já começaram a receber as dietas artificiais e as folhas “in natura”. Quando as larvas receberam folhas “in natura”, ao longo dos ínstares, apresentaram valores superiores para peso dos casulos. Por outro lado, quando receberam dietas artificiais, nos dois ínstares iniciais, não apresentaram diferença significativa para teor líquido de seda, quando comparadas com folhas “in natura”. Por fim, observou-se que a variedade Miura é melhor tanto como folha “in natura”, quanto como dieta artificial para peso de casulos.The utilization of artificial diets in Japan is fact and in Brazil the work is beginning to search meeting a balance form to satisfy the silkworm necessity, Bombyx mori (Lepidoptera. In such case, was tested two cultivars of mulberry in diets, to evaluate the quality of food trough mean cocoon weight and liquid silk. The larvae were separated in portion in the first instar begin and were to feed with diets and leaves “in nature”. When the silkworms were fed with leaves during five instars, showed cocoon weight high. When were fed diets in two inicial instars, showed that the silk liquid was good. The Miura variety is better in diets and leaves “in nature” for coccon weight.

Genome engineering and parthenocloning in the silkworm, Bombyx ...

Indian Academy of Sciences (India)

Genetic engineering of the silkworm, Bombyx mori, opens door to the production of new kinds of silk and to the use of silkworms as proteosynthetic bioreactors. The insertion of foreign genes into silkworm genome and the control of their expression by diverse promoters have become possible but are not yet efficient enough ...

Subcellular localization of Bombyx mori ribosomal protein S3a and ...

African Journals Online (AJOL)

USER

2010-04-05

Apr 5, 2010 ... In the present study, using a BV/PH-Bms3a-EGFP, we found that Bombyx mori ribosomal protein S3a. (BmS3a) with EGFP fused to its C-terminal, was predominantly localized in the cytoplasm of B. mori cells. Subsequently, to investigate the effect of BmS3a over-expression on BmNPV infection both at the.

Caspase-1 from the silkworm, Bombyx mori, is involved in Bombyx mori nucleopolyhedrovirus infection.

Science.gov (United States)

Wang, Qiang; Ju, Xiaoli; Chen, Liang; Chen, Keping

2017-03-01

Caspase-1 is one of the effector caspases in mammals that plays a central role in apoptosis. However, the lepidopteran caspase-1, especially the Bombyx mori caspase-1 (Bm-caspase-1), has not been investigated in detail. In this study, Bm-caspase-1 was identified from an expressed sequence tag database in B. mori by BLAST search. The open reading frame of Bm-caspase-1 contained 879 nucleotides and encoded 293 amino acids with a predicted molecular mass of 33 kDa. Bm-caspase-1 contained two consensus amino acid motifs of caspase cleavage sites, DEGDA and TETDG. Caspase activity assays revealed significant proteolytic activity of the Ac-DEVD-pNA substrate. Bm-caspase-1 can be detected in all tissues and developmental stages by a semi quantitative polymerase chain reaction assay. More importantly, the expression level of Bm-caspase-1 is increased upon baculovirus infection and up-regulated in BmNPV-resistant silkworms. Taken together, these results indicate that Bm-caspase-1 plays an important role during baculovirus infection.

Sequential steps of macroautophagy and chaperone-mediated autophagy are involved in the irreversible process of posterior silk gland histolysis during metamorphosis of Bombyx mori.

Science.gov (United States)

Shiba, Hajime; Yabu, Takeshi; Sudayama, Makoto; Mano, Nobuhiro; Arai, Naoto; Nakanishi, Teruyuki; Hosono, Kuniaki

2016-04-15

To elucidate the degradation process of the posterior silk gland during metamorphosis of the silkworm ITALIC! Bombyx mori, tissues collected on the 6th day after entering the 5th instar (V6), prior to spinning (PS), during spinning (SP) and after cocoon formation (CO) were used to analyze macroautophagy, chaperone-mediated autophagy (CMA) and the adenosine triphosphate (ATP)-dependent ubiquitin proteasome. Immediately after entering metamorphosis stage PS, the levels of ATP and phosphorylated p70S6 kinase protein decreased spontaneously and continued to decline at SP, followed by a notable restoration at CO. In contrast, phosphorylated AMP-activated protein kinase α (AMPKα) showed increases at SP and CO. Most of the Atg8 protein was converted to form II at all stages. The levels of ubiquitinated proteins were high at SP and CO, and low at PS. The proteasome activity was high at V6 and PS but low at SP and CO. In the isolated lysosome fractions, levels of Hsc70/Hsp70 protein began to increase at PS and continued to rise at SP and CO. The lysosomal cathepsin B/L activity showed a dramatic increase at CO. Our results clearly demonstrate that macroautophagy occurs before entering the metamorphosis stage and strongly suggest that the CMA pathway may play an important role in the histolysis of the posterior silk gland during metamorphosis. © 2016. Published by The Company of Biologists Ltd.

Biological and molecular characterization of silkworm strains from the Brazilian germplasm bank of Bombyx mori.

Science.gov (United States)

Pereira, N C; Munhoz, R E F; Bignotto, T S; Bespalhuk, R; Garay, L B; Saez, C R N; Fassina, V A; Nembri, A; Fernandez, M A

2013-06-28

Brazil has only one public genetic pool of Bombyx mori strains, which was established in 2005 at Universidade Estadual de Maringá, Maringá, Paraná State. This genetic bank has been maintained, and the strains have been characterized using genetic and morphological tools. The quantitative and qualitative traits, directly or indirectly related to productivity, were evaluated in 14 silkworm strains. In addition to biological and productivity analyses, DNA markers related to susceptibility to the B. mori nucleopolyhedrovirus (BmNPV) were analyzed. BmNPV is a major cause of production loss and is a serious problem for Paraná sericulture. The silkworm strains from diverse geographic origins were found to have different characteristics, including body weight, larval stage duration, cocoon weight, and other biological traits. In terms of productivity, the raw silk percentages were almost uniform, with an overall average of 16.28%. Overall, the Chinese strain C37 gave the best performance in many of the quantitative traits, and it surpassed the other strains in productivity traits. Therefore, it can be used as one of the strains that compose the elite germplasm for silkworm breeding programs. Additionally, genetic molecular markers were efficient in discriminating between B. mori strains that had been identified based on their geographical origin. We found that all Japanese strains produced a 400-bp molecular marker that has been associated with susceptibility to BmNPV.

Impact of microsporidian infection on growth and development of silkworm Bombyx mori L. (Lepidoptera: Bombycidae

Directory of Open Access Journals (Sweden)

Sunil Kumar Gupta

2016-09-01

Full Text Available Several species and strains of microsporidia have been isolated from infected silkworms among which pebrine caused by Nosema bombycis Nageli is the most important. Infection from this disease causes severe economic loss in sericulture. Reduction of larval and pupal development and reduced weights in silkworms due to infection has been reported. In the present study, five microsporidian (Nosema isolates from mulberry silkworm, Bombyx mori L. collected from different locations in West Bengal, India were sampled to study the impact of their infection on the growth and development of B. mori. The study revealed significant differences among the isolates in their ability to cause a reduction in the larval and pupal development of silkworm. Healthy larvae showed better body and tissue weights which were significantly higher than in infected lots. Among the isolates, M5 registered the maximum reduction in relative growth rate, larval silk gland tissue somatic index, larval male and female gonad tissue somatic index (GTSI and pupal female GTSI compared to the healthy control. Male and female pupa treated with M5 spores died before emergence, suggesting that the M5 isolate was the most virulent.

Transposable-element associated small RNAs in Bombyx mori genome.

Directory of Open Access Journals (Sweden)

Yimei Cai

Full Text Available Small RNAs are a group of regulatory RNA molecules that control gene expression at transcriptional or post-transcriptional levels among eukaryotes. The silkworm, Bombyx mori L., genome harbors abundant repetitive sequences derived from families of retrotransposons and transposons, which together constitute almost half of the genome space and provide ample resource for biogenesis of the three major small RNA families. We systematically discovered transposable-element (TE-associated small RNAs in B. mori genome based on a deep RNA-sequencing strategy and the effort yielded 182, 788 and 4,990 TE-associated small RNAs in the miRNA, siRNA and piRNA species, respectively. Our analysis suggested that the three small RNA species preferentially associate with different TEs to create sequence and functional diversity, and we also show evidence that a Bombyx non-LTR retrotransposon, bm1645, alone contributes to the generation of TE-associated small RNAs in a very significant way. The fact that bm1645-associated small RNAs partially overlap with each other implies a possibility that this element may be modulated by different mechanisms to generate different products with diverse functions. Taken together, these discoveries expand the small RNA pool in B. mori genome and lead to new knowledge on the diversity and functional significance of TE-associated small RNAs.

Attachment and growth of human bone marrow derived mesenchymal stem cells on regenerated antheraea pernyi silk fibroin films

Energy Technology Data Exchange (ETDEWEB)

Luan Xiying [Institute of Medical Biotechnology, Jiangsu Province Key Laboratory of Stem Cell, Suzhou University, Suzhou 215007 (China); Wang Yong [Institute of Medical Biotechnology, Jiangsu Province Key Laboratory of Stem Cell, Suzhou University, Suzhou 215007 (China); Duan Xiang [Institute of Medical Biotechnology, Jiangsu Province Key Laboratory of Stem Cell, Suzhou University, Suzhou 215007 (China); Duan Qiaoyan [Institute of Medical Biotechnology, Jiangsu Province Key Laboratory of Stem Cell, Suzhou University, Suzhou 215007 (China); Li Mingzhong [School of Materials Engineering, Suzhou University, Suzhou 215006 (China); Lu Shenzhou [School of Materials Engineering, Suzhou University, Suzhou 215006 (China); Zhang Huanxiang [Institute of Medical Biotechnology, Jiangsu Province Key Laboratory of Stem Cell, Suzhou University, Suzhou 215007 (China); Zhang Xueguang [Institute of Medical Biotechnology, Jiangsu Province Key Laboratory of Stem Cell, Suzhou University, Suzhou 215007 (China)

2006-12-15

Silk fibroin of the silkworm Bombyx mori has been studied extensively, while the research on Antheraea pernyi silk fibroin (A. pernyi SF) in biomaterials is only at an early stage. In this study, the attachment, morphology, growth and phenotype of human bone marrow derived mesenchymal stem cells (hBMSCs) cultured on the regenerated A. pernyi SF films were studied in vitro. The results indicated that the attachment of hBMSCs on the regenerated A. pernyi SF films was almost the same as that on the collagen films. MTT and cell counting analyses demonstrated that the growth of hBMSCs on the regenerated A. pernyi SF films was better than that on controls. Moreover, electron scanning microscopy and fluorescence-activated cell sorting assays showed that the regenerated A. pernyi SF supported hBMSCs growth and functional maintenance compared with the controls. These data suggest that the regenerated A. pernyi SF, like Bombyx mori silk fibroin (B. mori SF) and collagen, can support hBMSCs attachment, growth and phenotypic maintenance, and has better biocompatibilities for hBMSCs in vitro culture.

Attachment and growth of human bone marrow derived mesenchymal stem cells on regenerated antheraea pernyi silk fibroin films

International Nuclear Information System (INIS)

Luan Xiying; Wang Yong; Duan Xiang; Duan Qiaoyan; Li Mingzhong; Lu Shenzhou; Zhang Huanxiang; Zhang Xueguang

2006-01-01

Silk fibroin of the silkworm Bombyx mori has been studied extensively, while the research on Antheraea pernyi silk fibroin (A. pernyi SF) in biomaterials is only at an early stage. In this study, the attachment, morphology, growth and phenotype of human bone marrow derived mesenchymal stem cells (hBMSCs) cultured on the regenerated A. pernyi SF films were studied in vitro. The results indicated that the attachment of hBMSCs on the regenerated A. pernyi SF films was almost the same as that on the collagen films. MTT and cell counting analyses demonstrated that the growth of hBMSCs on the regenerated A. pernyi SF films was better than that on controls. Moreover, electron scanning microscopy and fluorescence-activated cell sorting assays showed that the regenerated A. pernyi SF supported hBMSCs growth and functional maintenance compared with the controls. These data suggest that the regenerated A. pernyi SF, like Bombyx mori silk fibroin (B. mori SF) and collagen, can support hBMSCs attachment, growth and phenotypic maintenance, and has better biocompatibilities for hBMSCs in vitro culture

Efficient TALEN construction for Bombyx mori gene targeting

Czech Academy of Sciences Publication Activity Database

Takasu, Y.; Sajwan, Suresh; Daimon, T.; Osanai-Futahashi, M.; Uchino, K.; Sezutsu, H.; Tamura, T.; Žurovec, Michal

2013-01-01

Roč. 8, č. 9 (2013), e73458 E-ISSN 1932-6203 R&D Projects: GA ČR GAP305/10/2406 Grant - others:Japan Society for the Promotion of Science(JP) 23580083 Institutional support: RVO:60077344 Keywords : Bombyx mori Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 3.534, year: 2013 http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0073458

Effect of Wheat Flour Noodles with Bombyx mori Powder on Glycemic Response in Healthy Subjects

Science.gov (United States)

Suk, Wanhee; Kim, JiEun; Kim, Do-Yeon; Lim, Hyunjung; Choue, Ryowon

2016-01-01

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±4.5 years, body mass index: 23.2±1.1 kg/m2) 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. PMID:27752491

Silk nanoparticles—an emerging anticancer nanomedicine

Directory of Open Access Journals (Sweden)

F. Philipp Seib

2017-03-01

Full Text Available Silk is a sustainable and ecologically friendly biopolymer with a robust clinical track record in humans for load bearing applications, in part due to its excellent mechanical properties and biocompatibility. Our ability to take bottom-up and top-down approaches for the generation of silk (inspired biopolymers has been critical in supporting the evolution of silk materials and formats, including silk nanoparticles for drug delivery. Silk nanoparticles are emerging as interesting contenders for drug delivery and are well placed to advance the nanomedicine field. This review covers the use of Bombyx mori and recombinant silks as an anticancer nanomedicine, highlighting the emerging trends and developments as well as critically assessing the current opportunities and challenges by providing a context specific assessment of this multidisciplinary field.

Natural Silk as a Photonics Component: a Study on Its Light Guiding and Nonlinear Optical Properties

OpenAIRE

Kujala, Sami; Mannila, Anna; Karvonen, Lasse; Kieu, Khanh; Sun, Zhipei

2016-01-01

Silk fibers are expected to become a pathway to biocompatible and bioresorbable waveguides, which could be used to deliver localized optical power for various applications, e.g., optical therapy or imaging inside living tissue. Here, for the first time, the linear and nonlinear optical properties of natural silk fibers have been studied. The waveguiding properties of silk fibroin of largely unprocessed Bombyx mori silkworm silk are assessed using two complementary methods, and found to be on ...

Depletion of juvenile hormone esterase extends larval growth in Bombyx mori.

Science.gov (United States)

Zhang, Zhongjie; Liu, Xiaojing; Shiotsuki, Takahiro; Wang, Zhisheng; Xu, Xia; Huang, Yongping; Li, Muwang; Li, Kai; Tan, Anjiang

2017-02-01

Two major hormones, juvenile hormone (JH) and 20-hydroxyecdysone (20E), regulate insect growth and development according to their precisely coordinated titres, which are controlled by both biosynthesis and degradation pathways. Juvenile hormone esterase (JHE) is the primary JH-specific degradation enzyme that plays a key role in regulating JH titers, along with JH epoxide hydrolase (JHEH) and JH diol kinase (JHDK). In the current study, a loss-of-function analysis of JHE in the silkworm, Bombyx mori, was performed by targeted gene disruption using the transgenic CRISPR/Cas9 (clustered regularly interspaced short palindromic repeats/RNA-guided Cas9 nucleases) system. Depletion of B. mori JHE (BmJHE) resulted in the extension of larval stages, especially the penultimate and ultimate larval stages, without deleterious effects to silkworm physiology. The expression of JHEH and JHDK was upregulated in mutant animals, indicating the existence of complementary routes in the JH metabolism pathway in which inactivation of one enzyme will activate other enzymes. RNA-Seq analysis of mutant animals revealed that genes involved in protein processing in the endoplasmic reticulum and in amino acid metabolism were affected by BmJHE depletion. Depletion of JHE and subsequent delayed JH metabolism activated genes in the TOR pathway, which are ultimately responsible for extending larval growth. The transgenic Cas9 system used in the current study provides a promising approach for analysing the actions of JH, especially in nondrosophilid insects. Furthermore, prolonging larval stages produced larger larvae and cocoons, which is greatly beneficial to silk production. Copyright © 2017 Elsevier Ltd. All rights reserved.

Comparative Study of Silk-Silk Alloy Materials

Science.gov (United States)

Xue, Ye; Jao, Dave; Hu, Wenbing; Wolf, Nathan; Rocks, Eva-Marie; Hu, Xiao

Silk fibroin materials can be used for various kinds of biomedical applications. We report a comparative study of silk-silk blend materials using thermal analysis and infrared spectroscopy. Four groups of silk-silk blend films: Mori-Tussah, Mori-Muga, Mori-Eri and Mori-Thai, were fabricated from aqueous solutions and blended at different weight ratios, respectively. These silk-silk blend systems exploit the beneficial material properties of both silks. DSC and temperature-modulated DSC were used to measure the transition temperatures and heat capacity of these water-based silk-silk blend films. Fourier transform infrared spectrometer was used to characterize secondary structures of silk-silk blends. This study demonstrates that Mori silk are fully miscible with Tussah, Muga, Eri and Thai silk at different weight ratios without phase separation. Glass transition temperatures, degradation temperatures and the contents of alpha-helix and random coils of those silk-silk blend films can be controlled by changing the contents of different silks in the blend system. The features of Mori silk combined with the attributes of Tussah, Muga, Eri and Thai silk offer a useful suite of materials for a variety of applications in the future.

In silico Identification of Novel Chitinase-Like Proteins in the Silkworm, Bombyx mori, Genome

Science.gov (United States)

Pan, Ye; Lü, Peng; Wang, Yong; Yin, Lijing; Ma, Hexiang; Ma, Guohong; Chen, Keping; He, Yuanqing

2012-01-01

In insects, chitinases participate in the periodic shedding of old exoskeletons and the turnover of peritrophic membranes. Chitinase family members have been identified in dozens of species, including Tribolium castaneum, Drosophila melanogaster, and Anopheles gambiae. In this study, nine chitinases and three hypothetical chitinases have been identified in Bombyx mori L. (Lepidoptera: Bombycidae) through genome-wide searching. Phylogenetic analyses revealed that seven of them belong to the seven chitinase groups, respectively. BmCht25 and BmCht26 could not be grouped into the known chitinase groups, and might belong to two new groups of the chitinase family. BmCht10, BmCht25, and BmIDGF have glutamate amino acid substitutions in the active catalytic domain. Only BmCht5 and BmCht10 contain CBD domain and PEST sequences (rich in proline, glutamic acid, serine, and threonine). BmCht5 and BmCht26 are located on chromosome 7, and others (BmCht6, BmCht7, BmCht10, BmCht11, BmCht20, BmIDGF) are located on separate chromosomes of Bombyx mori, respectively. The present study provides important background information for future studies using Bombyx mori as a model organism for insect development and virus and host interaction. PMID:23461297

Thromboelastometric and platelet responses to silk biomaterials.

Science.gov (United States)

Kundu, Banani; Schlimp, Christoph J; Nürnberger, Sylvia; Redl, Heinz; Kundu, S C

2014-05-13

Silkworm's silk is natural biopolymer with unique properties including mechanical robustness, all aqueous base processing and ease in fabrication into different multifunctional templates. Additionally, the nonmulberry silks have cell adhesion promoting tri-peptide (RGD) sequences, which make it an immensely potential platform for regenerative medicine. The compatibility of nonmulberry silk with human blood is still elusive; thereby, restricts its further application as implants. The present study, therefore, evaluate the haematocompatibility of silk biomaterials in terms of platelet interaction after exposure to nonmulberry silk of Antheraea mylitta using thromboelastometry (ROTEM). The mulberry silk of Bombyx mori and clinically used Uni-Graft W biomaterial serve as references. Shortened clotting time, clot formation times as well as enhanced clot strength indicate the platelet mediated activation of blood coagulation cascade by tested biomaterials; which is comparable to controls.

A highly divergent gene cluster in honey bees encodes a novel silk family

OpenAIRE

Sutherland, Tara D.; Campbell, Peter M.; Weisman, Sarah; Trueman, Holly E.; Sriskantha, Alagacone; Wanjura, Wolfgang J.; Haritos, Victoria S.

2006-01-01

The pupal cocoon of the domesticated silk moth Bombyx mori is the best known and most extensively studied insect silk. It is not widely known that Apis mellifera larvae also produce silk. We have used a combination of genomic and proteomic techniques to identify four honey bee fiber genes (AmelFibroin1–4) and two silk-associated genes (AmelSA1 and 2). The four fiber genes are small, comprise a single exon each, and are clustered on a short genomic region where the open reading frames are GC-r...

Bombyx mori Serpin6 regulates prophenoloxidase activity and the expression of antimicrobial proteins.

Science.gov (United States)

Li, Bing; Yu, Hai-Zhong; Ye, Chong-Jun; Ma, Yan; Li, Xing; Fan, Tao; Chen, Fu-Sheng; Xu, Jia-Ping

2017-04-30

Serpins are a family of serine protease inhibitors that are found widely in insects. They play an important role in insect physiological responses, such as innate immunity and development. In this study, we obtained the Bombyx mori serpin6 (BmSerpin6) sequence from National Center for Biotechnology Information (NCBI) and the silkworm genome database (SilkDB). Reverse transcription PCR (RT-PCR) results showed that BmSerpin6 was expressed highly in hemocytes, the midgut, and the fat body. After challenging with Micrococcus luteus (Mi) and Serratia marcescens (Sm), the BmSerpin6 expression level was induced significantly. Transcript levels of gloverin2 and prophenoloxidase (PPO) activity were reduced significantly in the fat body and hemocytes after injecting the recombinant BmSerpin6 protein into silkworm larvae. A BmSerpin6 recombinant plasmid (BmSerpin6-pAC 5.1) was constructed successfully and transfected into Drosophila S2 cells, which resulted in significantly reduced expression of the drosomycin protein. These results indicated that BmSerpin6 might regulate silkworm immune responses. Copyright © 2017 Elsevier B.V. All rights reserved.

STUDY OF PHENOTYPIC CHARACTERS VARIABILITY OF THE SILKMOTH COCOON FROM THE NATIVE GENETIC STOCK OF BOMBYX MORI L. SP.

Directory of Open Access Journals (Sweden)

ALEXANDRA MATEI

2008-10-01

Full Text Available This study had aims the analysis of phenotypic characters variability of silkmoth cocoon within the native genetic stock of Bombyx mori L. sp. The biological material was represented by 72 races consisting of the gene stock of Bombyx mori sp., grouped by their origin. The main phenotypical ad quantitative parameters of the races that represent the gene stock of Bombyx mori sp., present the following values: raw cocoon weight (1.445-2.361 g, cocoon shell weight (0.240-0.520 g, fiber length (746-1356 m, metric number of fiber (2917-3764 m/g. Depending on the quantitative parameters value, the silkworm races are being used differently, entire genetic stock being destined for various technological levels, as follows: 4 active races (parents of hybrids, 4 candidate races for parents of hybrids, 64 races in preservation.

Expression of RYamide in the nervous and endocrine system of Bombyx mori.

Science.gov (United States)

Roller, Ladislav; Čižmár, Daniel; Bednár, Branislav; Žitňan, Dušan

2016-06-01

RYamides are neuropeptides encoded by a gene whose precise expression and function have not yet been determined. We identified the RYamide gene transcript (fmgV1g15f, SilkBase database) and predicted two candidates for G-protein coupled RYamide receptors (A19-BAG68418 and A22-BAG68421) in the silkworm Bombyx mori. We cloned the RYamide transcript and described its spatial expression using in situ hybridisation. In the larval central nervous system (CNS) expression of RYamide was restricted to 12-14 small neurons in the brain and two posterior neurons in the terminal abdominal ganglion. During metamorphosis their number decreased to eight protocerebral neurons in the adults. Multiple staining, using various insect neuropeptide antibodies, revealed that neurons expressing RYamide are different from other peptidergic cells in the CNS. We also found RYamide expression in the enteroendocrine cells (EC) of the anterior midgut of larvae, pupae and adults. Two minor subpopulations of these EC were also immunoreactive to antibodies against tachykinin and myosupressin. This expression pattern suggests RYamides may play a role in the regulation of feeding and digestion. Copyright © 2016 Elsevier Inc. All rights reserved.

Crystallization and preliminary X-ray analysis of cecropin B from Bombyx mori

International Nuclear Information System (INIS)

Liu, Zhongyuan; Zhou, Qiangjun; Mao, Xinfang; Zheng, Xiangdong; Guo, Jiubiao; Zhang, Fuchun; Wen, Tingyi; Pang, Hai

2010-01-01

Cecropin B derived from the hemolymph of Bombyx mori has been crystallized by the hanging-drop vapour-diffusion method. The crystal diffracted to 1.43 Å resolution using X-ray radiation. Cecropin B is a 37-residue cationic antimicrobial peptide derived from the haemolymph of Bombyx mori. The precise mechanism by which cecropins exert their antimicrobial and cytolytic activities is not well understood. Crystals of cecropin B were obtained by the hanging-drop vapour-diffusion method using polyethylene glycol as a precipitant at 289 K. The crystal diffracted to 1.43 Å resolution using X-ray radiation and belonged to the orthorhombic space group P1, with unit-cell parameters a = 15.08, b = 22.75, c = 30.20 Å, α = 96.9, β = 103.1, γ = 96.5°. The asymmetric unit contained only one molecule of cecropin B, with a calculated Matthews coefficient of 2.48 Å 3 Da −1 and a solvent content of 50.4%

BAC-FISH mapping of synteny between chromosomes of Bombyx mori and Manducta sexta

Czech Academy of Sciences Publication Activity Database

Sahara, K.; Yoshido, A.; Marec, František; Vrbová, Iva; Kamimura, M.; Yasukochi, Y.

2007-01-01

Roč. 15, suppl. 2 (2007), s. 32-32 ISSN 0967-3849. [International Chromosome Conference /16./. 25.08.2007-29.08.2007, Amsterdam] Institutional research plan: CEZ:AV0Z50070508 Keywords : Bombyx mori Subject RIV: EB - Genetics ; Molecular Biology

Characterization of Bombyx mori nucleopolyhedrovirus Bm17.

Science.gov (United States)

Shen, Hongxing; Wang, Rudu; Han, Qinggong; Zhang, Wen; Nin, Bin; Zhou, Yang; Shao, Shihe; Yao, Qin; Chen, Keping; Liu, Xiaoyong

2013-10-01

Open reading frame17 (Bm17) of Bombyx mori nucleopolyhedrovirus is a highly conserved gene in lepidopteran nucleopolyhedroviruses, suggesting that it performs an important role in the virus life cycle whose function is unknown. In this report, we describe the characterization of Bm17. Reversed transcriptive-PCR (RT-PCR) and Western blot analysis demonstrated that Bm17 was expressed as a late gen. Immunofluorescence analysis by confocal microscopy showed that BM17 protein was localized on cytoplasm and nucleus of infected cells. These results show that BM17 was a late protein localized in cytoplasm and nucleus. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Diapause prevention effect of Bombyx mori by dimethyl sulfoxide.

Directory of Open Access Journals (Sweden)

Takayuki Yamamoto

Full Text Available HCl treatment has been, for about 80 years, the primary method for the prevention of entry into embryonic diapauses of Bombyx mori. This is because no method is as effective as the HCl treatment. In this study, we discovered that dimethyl sulfoxide (DMSO prevented entry into the diapause of the silkworm, Bombyx mori. The effect of diapause prevention was 78% as a result of treatment with 100% DMSO concentration, and the effect was comparable to that of the HCl treatment. In contrast, in the case of non-diapause eggs, hatchability was decreased by DMSO in a concentration-dependent manner. The effect of DMSO was restricted within 24 hours after oviposition of diapause eggs, and the critical period was slightly shorter than the effective period of the HCl treatment. DMSO analogs, such as dimethyl formamide (DMF and dimethyl sulfide (DMS, did little preventive effect against the diapause. Furthermore, we also investigated the permeation effects of chemical compounds by DMSO. When treated with an inhibitor of protein kinase CK2 (CK2 dissolved in DMSO, the prevention rate of the diapause was less than 40%. This means that the inhibition effect by the CK2 inhibitor was the inhibition of embryonic development after diapause prevention by DMSO. These data suggest that DMSO has the effects of preventing from entering into the diapause and permeation of chemicals into diapause eggs.

Timeless is a critical gene in the diapause of silkworm, Bombyx mori ...

African Journals Online (AJOL)

Timeless is a critical gene in the diapause of silkworm, Bombyx mori. L Xu, H Liang, LP Gan, WD Wang, YH Sima, SQ Xu. Abstract. The diapause is a specific physiological phenomenon induced by circadian zeitgebers of temperature and photoperiod at the stage of maternal embryonic development. In this research, the ...

Silk Electrogel Rheology

Science.gov (United States)

Tabatabai, A. P.; Urbach, J. S.; Blair, D. L.; Kaplan, D. L.

2014-03-01

We present experimental results on the rheology on electrogels derived from aqueous solutions of reconstituted Bombyx Mori silk fibroin protein. Through electrochemistry, the silk protein solution develops local pH changes resulting in the assembly of protein into a weak gel. We determine the physical properties of the electrogels by performing rheology and observe that they exhibit the characteristics of a crosslinked biopolymer network. Interestingly, we find that these silk gels exhibit linear elasticity over a range of up to two orders of magnitude larger than most crosslinked biopolymer networks. Moreover, the nonlinear rheology exhibits a strain-stiffening behavior that is fundamentally different than the strain-stiffening observed in crosslinked biopolymers. Through rheological techniques we aim to understand this distinctive material that cannot be explained by current polymeric models. This work is supported by a grant from the AFOSR FA9550-07-1-0130.

Protective effects of Bombyx mori, quercetin and benazepril against doxorubicin induced cardiotoxicity and nephrotoxicity

OpenAIRE

Abdul S. Nazmi; Shibli J. Ahmad; Krishna K. Pillai; Mohammad Akhtar; Aftab Ahmad; Abul K. Najmi

2016-01-01

The present study was conducted with the aim of evaluating the protective effects of Bombyx mori, quercetin and benazepril on doxorubicin (DXR) induced cardiotoxicity and nephrotoxicity in rats. B. mori, quercetin and benazepril were administered for 7 days, and a single intravenous injection of 10 mg/kg body weight of DXR on day five. The animals were sacrificed 48 h after DXR administration. DXR produced a significant elevation in the malondialdehyde (MDA) level and significantly inhibited ...

Characterization of an entomopathogenic fungi target integument protein, Bombyx mori single domain von Willebrand factor type C, in the silkworm, Bombyx mori.

Science.gov (United States)

Han, F; Lu, A; Yuan, Y; Huang, W; Beerntsen, B T; Huang, J; Ling, E

2017-06-01

The insect cuticle works as the first line of defence to protect insects from pathogenic infections and water evaporation. However, the old cuticle must be shed in order to enter the next developmental stage. During each ecdysis, moulting fluids are produced and secreted into the area among the old and new cuticles. In a previous study, the protein Bombyx mori single domain von Willebrand factor type C (BmSVWC; BGIBMGA011399) was identified in the moulting fluids of Bo. mori and demonstrated to regulate ecdysis. In this study we show that in Bo. mori larvae, BmSVWC primarily locates to the integument (epidermal cells and cuticle), wing discs and head. During the moulting stage, BmSVWC is released into the moulting fluids, and is then produced again by epidermal cells after ecdysis. Fungal infection was shown to decrease the amount of BmSVWC in the cuticle, which indicates that BmSVWC is a target protein of entomopathogenic fungi. Thus, BmSVWC is mainly involved in maintaining the integrity of the integument structure, which serves to protect insects from physical damage and pathogenic infection. © 2017 The Royal Entomological Society.

Functional characterization of the vitellogenin promoter in the silkworm, Bombyx mori.

Science.gov (United States)

Xu, J; Wang, Y Q; Li, Z Q; Ling, L; Zeng, B S; You, L; Chen, Y Z; Aslam, A F M; Huang, Y P; Tan, A J

2014-10-01

Genetic transformation and genome editing technologies have been successfully established in the lepidopteran insect model, the domesticated silkworm, Bombyx mori, providing great potential for functional genomics and practical applications. However, the current lack of cis-regulatory elements in B. mori gene manipulation research limits further exploitation in functional gene analysis. In the present study, we characterized a B. mori endogenous promoter, Bmvgp, which is a 798-bp DNA sequence adjacent to the 5'-end of the vitellogenin gene (Bmvg). PiggyBac-based transgenic analysis shows that Bmvgp precisely directs expression of a reporter gene, enhanced green fluorescent protein (EGFP), in a sex-, tissue- and stage-specific manner. In transgenic animals, EGFP expression can be detected in the female fat body from larval-pupal ecdysis to the following pupal and adult stage. Furthermore, in vitro and in vivo experiments revealed that EGFP expression can be activated by 20-hydroxyecdysone, which is consistent with endogenous Bmvg expression. These data indicate that Bmvgp is an effective endogenous cis-regulatory element in B. mori. © 2014 The Royal Entomological Society.

Biotechnology and Composite Materials

Science.gov (United States)

1993-04-01

means. Silk made from the caterpillar, Bombyx mori , has outstanding mechanical and good thermal properties. The Bombyx mori synthesises the components of...Silk Proteins for Composite Fibers 185 In natural systems, the two c=nm=n sources of silks are the dch!sticated silkworm, mori , and the orb weaving...unit cell remain parallel to their original orientation during deformation. This prevents the formation of any voids or gaps in the model. Using the

MicroRNA expression profiling during the life cycle of the silkworm (Bombyx mori

Directory of Open Access Journals (Sweden)

Cheng Daojun

2009-09-01

Full Text Available Abstract Background MicroRNAs (miRNAs are expressed by a wide range of eukaryotic organisms, and function in diverse biological processes. Numerous miRNAs have been identified in Bombyx mori, but the temporal expression profiles of miRNAs corresponding to each stage transition over the entire life cycle of the silkworm remain to be established. To obtain a comprehensive overview of the correlation between miRNA expression and stage transitions, we performed a whole-life test and subsequent stage-by-stage examinations on nearly one hundred miRNAs in the silkworm. Results Our results show that miRNAs display a wide variety of expression profiles over the whole life of the silkworm, including continuous expression from embryo to adult (miR-184, up-regulation over the entire life cycle (let-7 and miR-100, down-regulation over the entire life cycle (miR-124, expression associated with embryogenesis (miR-29 and miR-92, up-regulation from early 3rd instar to pupa (miR-275, and complementary pulses in expression between miR-34b and miR-275. Stage-by-stage examinations revealed further expression patterns, such as emergence at specific time-points during embryogenesis and up-regulation of miRNA groups in late embryos (miR-1 and bantam, expression associated with stage transition between instar and molt larval stages (miR-34b, expression associated with silk gland growth and spinning activity (miR-274, continuous high expression from the spinning larval to pupal and adult stages (miR-252 and miR-31a, a coordinate expression trough in day 3 pupae of both sexes (miR-10b and miR-281, up-regulation in pupal metamorphosis of both sexes (miR-29b, and down-regulation in pupal metamorphosis of both sexes (miR-275. Conclusion We present the full-scale expression profiles of miRNAs throughout the life cycle of Bombyx mori. The whole-life expression profile was further investigated via stage-by-stage analysis. Our data provide an important resource for more detailed

MicroRNA expression profiling during the life cycle of the silkworm (Bombyx mori).

Science.gov (United States)

Liu, Shiping; Zhang, Liang; Li, Qibin; Zhao, Ping; Duan, Jun; Cheng, Daojun; Xiang, Zhonghuai; Xia, Qingyou

2009-09-28

MicroRNAs (miRNAs) are expressed by a wide range of eukaryotic organisms, and function in diverse biological processes. Numerous miRNAs have been identified in Bombyx mori, but the temporal expression profiles of miRNAs corresponding to each stage transition over the entire life cycle of the silkworm remain to be established. To obtain a comprehensive overview of the correlation between miRNA expression and stage transitions, we performed a whole-life test and subsequent stage-by-stage examinations on nearly one hundred miRNAs in the silkworm. Our results show that miRNAs display a wide variety of expression profiles over the whole life of the silkworm, including continuous expression from embryo to adult (miR-184), up-regulation over the entire life cycle (let-7 and miR-100), down-regulation over the entire life cycle (miR-124), expression associated with embryogenesis (miR-29 and miR-92), up-regulation from early 3rd instar to pupa (miR-275), and complementary pulses in expression between miR-34b and miR-275. Stage-by-stage examinations revealed further expression patterns, such as emergence at specific time-points during embryogenesis and up-regulation of miRNA groups in late embryos (miR-1 and bantam), expression associated with stage transition between instar and molt larval stages (miR-34b), expression associated with silk gland growth and spinning activity (miR-274), continuous high expression from the spinning larval to pupal and adult stages (miR-252 and miR-31a), a coordinate expression trough in day 3 pupae of both sexes (miR-10b and miR-281), up-regulation in pupal metamorphosis of both sexes (miR-29b), and down-regulation in pupal metamorphosis of both sexes (miR-275). We present the full-scale expression profiles of miRNAs throughout the life cycle of Bombyx mori. The whole-life expression profile was further investigated via stage-by-stage analysis. Our data provide an important resource for more detailed functional analysis of miRNAs in this animal.

Structure of autophagy-related protein Atg8 from the silkworm Bombyx mori

International Nuclear Information System (INIS)

Hu, Chen; Zhang, Xuan; Teng, Yan-Bin; Hu, Hai-Xi; Li, Wei-Fang

2010-01-01

The crystal structure of autophagy-related protein Atg8 from the silkworm B. mori has two additional helices at the N-terminus before the expected ubiquitin fold. Autophagy-related protein Atg8 is ubiquitous in all eukaryotes. It is involved in the Atg8–PE ubiquitin-like conjugation system, which is essential for autophagosome formation. The structures of Atg8 from different species are very similar and share a ubiquitin-fold domain at the C-terminus. In the 2.40 Å crystal structure of Atg8 from the silkworm Bombyx mori reported here, the ubiquitin fold at the C-terminus is preceded by two additional helices at the N-terminus

Silk-Silk Interactions between Silkworm Fibroin and Recombinant Spider Silk Fusion Proteins Enable the Construction of Bioactive Materials.

Science.gov (United States)

Nilebäck, Linnea; Chouhan, Dimple; Jansson, Ronnie; Widhe, Mona; Mandal, Biman B; Hedhammar, My

2017-09-20

Natural silk is easily accessible from silkworms and can be processed into different formats suitable as biomaterials and cell culture matrixes. Recombinant DNA technology enables chemical-free functionalization of partial silk proteins through fusion with peptide motifs and protein domains, but this constitutes a less cost-effective production process. Herein, we show that natural silk fibroin (SF) can be used as a bulk material that can be top-coated with a thin layer of the recombinant spider silk protein 4RepCT in fusion with various bioactive motifs and domains. The coating process is based on a silk assembly to achieve stable interactions between the silk types under mild buffer conditions. The assembly process was studied in real time by quartz crystal microbalance with dissipation. Coatings, electrospun mats, and microporous scaffolds were constructed from Antheraea assama and Bombyx mori SFs. The morphology of the fibroin materials before and after coating with recombinant silk proteins was analyzed by scanning electron microscopy and atomic force microscopy. SF materials coated with various bioactive 4RepCT fusion proteins resulted in directed antibody capture, enzymatic activity, and improved cell attachment and spreading, respectively, compared to pristine SF materials. The herein-described procedure allows a fast and easy route for the construction of bioactive materials.

iTRAQ-based quantitative proteomic analysis of midgut in silkworm infected with Bombyx mori cytoplasmic polyhedrosis virus.

Science.gov (United States)

Gao, Kun; Deng, Xiang-Yuan; Shang, Meng-Ke; Qin, Guang-Xing; Hou, Cheng-Xiang; Guo, Xi-Jie

2017-01-30

Bombyx mori cytoplasmic polyhedrosis virus (BmCPV) specifically infects the epithelial cells in the midgut of silkworm and causes them to death, which negatively affects the sericulture industry. In order to determine the midgut response at the protein levels to the virus infection, differential proteomes of the silkworm midgut responsive to BmCPV infection were identified with isobaric tags for relative and absolute quantitation (iTRAQ) labeling followed by liquid chromatography-tandem mass spectrometry (LC-MS/MS). 193, 408, 189 differentially expressed proteins (DEPs) were reliably quantified by iTRAQ analysis in the midgut of BmCPV-infected and control larvae at 24, 48, 72h post infection (hpi) respectively. KEGG enrichment analysis showed that Oxidative phosphorylation, amyotrophic lateral sclerosis, Toll-like receptor signaling pathway, steroid hormone biosynthesis were the significant pathways (Q value≤0.05) both at 24 and 48hpi. qRT-PCR was used to further verify gene transcription of 30 DEPs from iTRAQ, showing that the regulations of 24 genes at the transcript level were consistent with those at the proteomic level. Moreover, the cluster analysis of the three time groups showed that there were seven co-regulated DEPs including BGIBMGA002620-PA, which was a putative p62/sequestosome-1 protein in silkworm. It was upregulated at both the mRNA level and the proteomic level and may play an important role in regulating the autophagy and apoptosis (especially apoptosis) induced by BmCPV infection. This was the first report using an iTRAQ approach to analyze proteomes of the silkworm midgut against BmCPV infection, which contributes to understanding the defense mechanisms of silkworm midgut to virus infection. The domesticated silkworm, Bombyx mori, is renowned for silk production as well as being a traditional lepidopteron model insect served as a subject for morphological, genetic, physiological, and developmental studies. Bombyx mori cytoplasmic polyhedrosis

Annotation and expression of carboxylesterases in the silkworm, Bombyx mori

Directory of Open Access Journals (Sweden)

Li Wen-Le

2009-11-01

Full Text Available Abstract Background Carboxylesterase is a multifunctional superfamily and ubiquitous in all living organisms, including animals, plants, insects, and microbes. It plays important roles in xenobiotic detoxification, and pheromone degradation, neurogenesis and regulating development. Previous studies mainly used Dipteran Drosophila and mosquitoes as model organisms to investigate the roles of the insect COEs in insecticide resistance. However, genome-wide characterization of COEs in phytophagous insects and comparative analysis remain to be performed. Results Based on the newly assembled genome sequence, 76 putative COEs were identified in Bombyx mori. Relative to other Dipteran and Hymenopteran insects, alpha-esterases were significantly expanded in the silkworm. Genomics analysis suggested that BmCOEs showed chromosome preferable distribution and 55% of which were tandem arranged. Sixty-one BmCOEs were transcribed based on cDNA/ESTs and microarray data. Generally, most of the COEs showed tissue specific expressions and expression level between male and female did not display obvious differences. Three main patterns could be classified, i.e. midgut-, head and integument-, and silk gland-specific expressions. Midgut is the first barrier of xenobiotics peroral toxicity, in which COEs may be involved in eliminating secondary metabolites of mulberry leaves and contaminants of insecticides in diet. For head and integument-class, most of the members were homologous to odorant-degrading enzyme (ODE and antennal esterase. RT-PCR verified that the ODE-like esterases were also highly expressed in larvae antenna and maxilla, and thus they may play important roles in degradation of plant volatiles or other xenobiotics. Conclusion B. mori has the largest number of insect COE genes characterized to date. Comparative genomic analysis suggested that the gene expansion mainly occurred in silkworm alpha-esterases. Expression evidence indicated that the expanded

Self-assembly of silk fibroin under osmotic stress

Science.gov (United States)

Sohn, Sungkyun

The supramolecular self-assembly behavior of silk fibroin was investigated using osmotic stress technique. In Chapter 2, a ternary phase diagram of water-silk-LiBr was constructed based on X-ray results on the osmotically stressed regenerated silk fibroin of Bombyx mori silkworm. Microscopic data indicated that silk I is a hydrated structure and a rough estimate of the number of water molecules lost by the structure upon converting from silk I to silk II has been made, and found to be about 2.2 per [GAGAGS] hexapeptide. In Chapter 3, wet-spinning of osmotically stressed, regenerated silk fibroin was performed, based on the prediction that the enhanced control over structure and phase behavior using osmotic stress method helps improve the physical properties of wet-spun regenerated silk fibroin fibers. The osmotic stress was applied in order to pre-structure the regenerated silk fibroin molecule from its original random coil state to more oriented state, manipulating the phase of the silk solution in the phase diagram before the start of spinning. Monofilament fiber with a diameter of 20 microm was produced. In Chapter 4, we investigated if there is a noticeable synergistic osmotic pressure increase between co-existing polymeric osmolyte and salt when extremely highly concentrated salt molecules are present both at sample subphase and stressing subphase, as is the case of silk fibroin self-assembly. The equilibration method that measures osmotic pressure relative to a reference with known osmotic pressure was introduced. Osmotic pressure of aqueous LiBr solution up to 2.75M was measured and it was found that the synergistic effect was insignificant up to this salt concentration. Solution parameters of stressing solutions and Arrhenius kinetics based on time-temperature relationship for the equilibration process were derived as well. In Chapter 5, self-assembly behavior of natural silk fibroin within the gland of Bombyx mori silkworm was investigated using osmotic

Water-insoluble Silk Films with Silk I Structure

Energy Technology Data Exchange (ETDEWEB)

Lu, Q.; Hu, X; Wang, X; Kluge, J; Lu, S; Cebe, P; Kaplan, D

2010-01-01

Water-insoluble regenerated silk materials are normally produced by increasing the {beta}-sheet content (silk II). In the present study water-insoluble silk films were prepared by controlling the very slow drying of Bombyx mori silk solutions, resulting in the formation of stable films with a predominant silk I instead of silk II structure. Wide angle X-ray scattering indicated that the silk films stabilized by slow drying were mainly composed of silk I rather than silk II, while water- and methanol-annealed silk films had a higher silk II content. The silk films prepared by slow drying had a globule-like structure at the core surrounded by nano-filaments. The core region was composed of silk I and silk II, surrounded by hydrophilic nano-filaments containing random turns and {alpha}-helix secondary structures. The insoluble silk films prepared by slow drying had unique thermal, mechanical and degradative properties. Differential scanning calorimetry results revealed that silk I crystals had stable thermal properties up to 250 C, without crystallization above the T{sub g}, but degraded at lower temperatures than silk II structure. Compared with water- and methanol-annealed films the films prepared by slow drying had better mechanical ductility and were more rapidly enzymatically degraded, reflecting the differences in secondary structure achieved via differences in post processing of the cast silk films. Importantly, the silk I structure, a key intermediate secondary structure for the formation of mechanically robust natural silk fibers, was successfully generated by the present approach of very slow drying, mimicking the natural process. The results also point to a new mode of generating new types of silk biomaterials with enhanced mechanical properties and increased degradation rates, while maintaining water insolubility, along with a low {beta}-sheet content.

Structural analysis and application to biomaterials of the silk fibroins

International Nuclear Information System (INIS)

Nakazawa, Yasumoto

2010-01-01

Silk fibroin from Bombyx mori silkworm has outstanding mechanical properties despite being spun from aqueous solution. I have clarified two distinct structures in the solid state; silk I and silk II, which mean the structures before and after spinning, by using solid state NMR. Moreover, I have been developing several kinds of biomaterials, such as bone regeneration materials and vascular grafts. In this paper, I present two topics: one is the structural analyses of the silk fibroin in detail, the other is applications of silk fibroins to tissue engineering. In the case of vascular regeneration, I have developed the small diameter vascular grafts made by silk fibroins. The new grafts from silk fibroins have good patency, and these grafts were commonly covered with cells and platelets at 4 weeks after implantation. For bone tissue engineering, I performed structural analyses of a new silk-like peptide, E n (AGSGAG) 4 , in order to consider the molecular design of biomaterials for bone regeneration. (author)

DNA replication events during larval silk gland development in the silkworm, Bombyx mori.

Science.gov (United States)

Zhang, Chun-Dong; Li, Fang-Fang; Chen, Xiang-Yun; Huang, Mao-Hua; Zhang, Jun; Cui, Hongjuan; Pan, Min-Hui; Lu, Cheng

2012-07-01

The silk gland is an important organ in silkworm as it synthesizes silk proteins and is critical to spinning. The genomic DNA content of silk gland cells dramatically increases 200-400 thousand times for the larval life span through the process of endomitosis. Using in vitro culture, DNA synthesis was measured using BrdU labeling during the larval molt and intermolt periods. We found that the cell cycle of endomitosis was activated during the intermolt and was inhibited during the molt phase. The anterior silk gland, middle silk gland, and posterior silk gland cells asynchronously exit the endomitotic cycle after day 6 in 5th instar larvae, which correlated with the reduced expression of the cell cycle-related cdt1, pcna, cyclin E, cdk2 and cdk1 mRNAs in the wandering phase. Additional starvation had no effect on the initiation of silk gland DNA synthesis of the freshly ecdysed larvae. Copyright © 2012 Elsevier Ltd. All rights reserved.

Silk-based biomaterials.

Science.gov (United States)

Altman, Gregory H; Diaz, Frank; Jakuba, Caroline; Calabro, Tara; Horan, Rebecca L; Chen, Jingsong; Lu, Helen; Richmond, John; Kaplan, David L

2003-02-01

Silk from the silkworm, Bombyx mori, has been used as biomedical suture material for centuries. The unique mechanical properties of these fibers provided important clinical repair options for many applications. During the past 20 years, some biocompatibility problems have been reported for silkworm silk; however, contamination from residual sericin (glue-like proteins) was the likely cause. More recent studies with well-defined silkworm silk fibers and films suggest that the core silk fibroin fibers exhibit comparable biocompatibility in vitro and in vivo with other commonly used biomaterials such as polylactic acid and collagen. Furthermore, the unique mechanical properties of the silk fibers, the diversity of side chain chemistries for 'decoration' with growth and adhesion factors, and the ability to genetically tailor the protein provide additional rationale for the exploration of this family of fibrous proteins for biomaterial applications. For example, in designing scaffolds for tissue engineering these properties are particularly relevant and recent results with bone and ligament formation in vitro support the potential role for this biomaterial in future applications. To date, studies with silks to address biomaterial and matrix scaffold needs have focused on silkworm silk. With the diversity of silk-like fibrous proteins from spiders and insects, a range of native or bioengineered variants can be expected for application to a diverse set of clinical needs.

Characterization of Bombyx mori nucleopolyhedrovirus with a knockout of Bm17

OpenAIRE

Shen, Hongxing; Zhou, Yang; Zhang, Wen; Nin, Bin; Wang, Hua; Wang, Xiaochun; Shao, Shihe; Chen, Huiqing; Guo, Zhongjian; Liu, Xiaoyong; Yao, Qin; Chen, Keping

2012-01-01

Open reading frame 17 (Bm17) gene of Bombyx mori nucleopolyhedrovirus is a highly conserved gene in lepidopteran nucleopolyhedroviruses, but its function remains unknown. In this report, transient-expression and superinfection assays indicated that BM17 localized in the nucleus and cytoplasm of infected BmN cells. To determine the role of Bm17 in baculovirus life cycle, we constructed a Bm17 knockout virus and characterized its properties in cells. Analysis of the production and infection of ...

Overview of research on Bombyx mori microRNA

Science.gov (United States)

Wang, Xin; Tang, Shun-ming; Shen, Xing-jia

2014-01-01

Abstract MicroRNAs (miRNAs) constitute some of the most significant regulatory factors involved at the post-transcriptional level after gene expression, contributing to the modulation of a large number of physiological processes such as development, metabolism, and disease occurrence. This review comprehensively and retrospectively explores the literature investigating silkworm, Bombyx mori L. (Lepidoptera: Bombicidae), miRNAs published to date, including discovery, identification, expression profiling analysis, target gene prediction, and the functional analysis of both miRNAs and their targets. It may provide experimental considerations and approaches for future study of miRNAs and benefit elucidation of the mechanisms of miRNAs involved in silkworm developmental processes and intracellular activities of other unknown non-coding RNAs. PMID:25368077

Screening for the genes involved in bombykol biosynthesis: Identification and functional characterization of Bombyx mori acyl carrier protein (BmACP

Directory of Open Access Journals (Sweden)

Atsushi eOhnishi

2011-12-01

Full Text Available Species-specific sex pheromones released by female moths to attract conspecific male moths are synthesized de novo in the pheromone gland (PG via fatty acid synthesis (FAS. Biosynthesis of moth sex pheromones is usually regulated by a neurohormone termed pheromone biosynthesis activating neuropeptide (PBAN, a 33-aa peptide that originates in the subesophageal ganglion. In the silkmoth, Bombyx mori, cytoplasmic lipid droplets (LDs, which store the sex pheromone (bombykol precursor fatty acid, accumulate in PG cells prior to eclosion. PBAN activation of the PBAN receptor stimulates lipolysis of the stored LD triacylglycerols (TAGs resulting in release of the bombykol precursor for final modification. While we have previously characterized a number of molecules involved in bombykol biosynthesis, little is known about the mechanisms of PBAN signaling that regulate the TAG lipolysis in PG cells. In the current study, we sought to further identify genes involved in bombykol biosynthesis as well as PBAN signaling, by using a subset of 312 expressed sequence tag (EST clones that are in either our B. mori PG cDNA library or the public B. mori EST databases, SilkBase and CYBERGATE, and which are preferentially expressed in the PG. Using RT-PCR expression analysis and an RNAi screening approach, we have identified another 8 EST clones involved in bombykol biosynthesis. Furthermore, we have determined the functional role of a clone designated BmACP that encodes B. mori acyl carrier protein (ACP. Our results indicate that BmACP plays an essential role in the biosynthesis of the bombykol precursor fatty acid via the canonical FAS pathway during pheromonogenesis.

Nutrigenetic Screening Strains of the Mulberry Silkworm, Bombyx mori, for Nutritional Efficiency

OpenAIRE

Ramesha, Chinnaswamy; Lakshmi, Hothur; Kumari, Savarapu Sugnana; Anuradha, Chevva M.; Kumar, Chitta Suresh

2012-01-01

The activity of sericulture is declining due the reduction of mulberry production area in sericulture practicing countries lead to adverse effects on silkworm rearing and cocoon production. Screening for nutrigenetic traits in silkworm, Bombyx mori L. (Lepidoptera: Bombycidae) is an essential prerequisite for better understanding and development of nutritionally efficient breeds/hybrids, which show less food consumption with higher efficiency conversion. The aim of this study was to identify ...

Study of recombinant proteins derived from Ser-2 gene of Bombyx mori

OpenAIRE

STAŠKOVÁ, Tereza

2012-01-01

Four different variants of recombinant proteins derived from Bombyx mori Ser-2 gene were expressed in bacteria. The ability of these proteins to coat hydrofobic surfaces and to support growth of various types of adherent cells in vitro were examined. It was shown that these proteins support cell adhesion and proliferation, and could be used as coating agents to realize surfaces suitable for growth of vertebrate and insect cells.

Applicability of biotechnologically produced insect silks.

Science.gov (United States)

Herold, Heike M; Scheibel, Thomas

2017-09-26

Silks are structural proteins produced by arthropods. Besides the well-known cocoon silk, which is produced by larvae of the silk moth Bombyx mori to undergo metamorphosis inside their silken shelter (and which is also used for textile production by men since millennia), numerous further less known silk-producing animals exist. The ability to produce silk evolved multiple independent times during evolution, and the fact that silk was subject to convergent evolution gave rise to an abundant natural diversity of silk proteins. Silks are used in air, under water, or like honey bee silk in the hydrophobic, waxen environment of the bee hive. The good mechanical properties of insect silk fibres together with their non-toxic, biocompatible, and biodegradable nature renders these materials appealing for both technical and biomedical applications. Although nature provides a great diversity of material properties, the variation in quality inherent in materials from natural sources together with low availability (except from silkworm silk) impeded the development of applications of silks. To overcome these two drawbacks, in recent years, recombinant silks gained more and more interest, as the biotechnological production of silk proteins allows for a scalable production at constant quality. This review summarises recent developments in recombinant silk production as well as technical procedures to process recombinant silk proteins into fibres, films, and hydrogels.

Identification and Analysis of the SET-Domain Family in Silkworm, Bombyx mori

Directory of Open Access Journals (Sweden)

Hailong Zhao

2015-01-01

Full Text Available As an important economic insect, Bombyx mori is also a useful model organism for lepidopteran insect. SET-domain-containing proteins belong to a group of enzymes named after a common domain that utilizes the cofactor S-adenosyl-L-methionine (SAM to achieve methylation of its substrates. Many SET-domain-containing proteins have been shown to display catalytic activity towards particular lysine residues on histones, but emerging evidence also indicates that various nonhistone proteins are specifically targeted by this clade of enzymes. To explore their diverse functions of SET-domain superfamily in insect, we identified, cloned, and analyzed the SET-domains proteins in silkworm, Bombyx mori. Firstly, 24 genes containing SET domain from silkworm genome were characterized and 17 of them belonged to six subfamilies of SUV39, SET1, SET2, SUV4-20, EZ, and SMYD. Secondly, SET domains of silkworm SET-domain family were intraspecifically and interspecifically conserved, especially for the catalytic core “NHSC” motif, substrate binding site, and catalytic site in the SET domain. Lastly, further analyses indicated that silkworm SET-domain gene BmSu(var3-9 owned different characterization and expression profiles compared to other invertebrates. Overall, our results provide a new insight into the functional and evolutionary features of SET-domain family.

Heritable genome editing with CRISPR/Cas9 in the silkworm, Bombyx mori.

Directory of Open Access Journals (Sweden)

Wei Wei

Full Text Available We report the establishment of an efficient and heritable gene mutagenesis method in the silkworm Bombyx mori using modified type II clustered regularly interspaced short palindromic repeats (CRISPR with an associated protein (Cas9 system. Using four loci Bm-ok, BmKMO, BmTH, and Bmtan as candidates, we proved that genome alterations at specific sites could be induced by direct microinjection of specific guide RNA and Cas9-mRNA into silkworm embryos. Mutation frequencies of 16.7-35.0% were observed in the injected generation, and DNA fragments deletions were also noted. Bm-ok mosaic mutants were used to test for mutant heritability due to the easily determined translucent epidermal phenotype of Bm-ok-disrupted cells. Two crossing strategies were used. In the first, injected Bm-ok moths were crossed with wild-type moths, and a 28.6% frequency of germline mutation transmission was observed. In the second strategy, two Bm-ok mosaic mutant moths were crossed with each other, and 93.6% of the offsprings appeared mutations in both alleles of Bm-ok gene (compound heterozygous. In summary, the CRISPR/Cas9 system can act as a highly specific and heritable gene-editing tool in Bombyx mori.

Identifying potential maternal genes of Bombyx mori using digital gene expression profiling

Science.gov (United States)

Xu, Pingzhen

2018-01-01

Maternal genes present in mature oocytes play a crucial role in the early development of silkworm. Although maternal genes have been widely studied in many other species, there has been limited research in Bombyx mori. High-throughput next generation sequencing provides a practical method for gene discovery on a genome-wide level. Herein, a transcriptome study was used to identify maternal-related genes from silkworm eggs. Unfertilized eggs from five different stages of early development were used to detect the changing situation of gene expression. The expressed genes showed different patterns over time. Seventy-six maternal genes were annotated according to homology analysis with Drosophila melanogaster. More than half of the differentially expressed maternal genes fell into four expression patterns, while the expression patterns showed a downward trend over time. The functional annotation of these material genes was mainly related to transcription factor activity, growth factor activity, nucleic acid binding, RNA binding, ATP binding, and ion binding. Additionally, twenty-two gene clusters including maternal genes were identified from 18 scaffolds. Altogether, we plotted a profile for the maternal genes of Bombyx mori using a digital gene expression profiling method. This will provide the basis for maternal-specific signature research and improve the understanding of the early development of silkworm. PMID:29462160

Viral Small-RNA Analysis of Bombyx mori Larval Midgut during Persistent and Pathogenic Cytoplasmic Polyhedrosis Virus Infection

OpenAIRE

Zografidis, Aris; Van Nieuwerburgh, Filip; Kolliopoulou, Anna; Apostolou-Karampelis, Konstantinos; Head, Steven R.; Deforce, Dieter; Smagghe, Guy; Swevers, Luc

2015-01-01

The lepidopteran innate immune response against RNA viruses remains poorly understood, while in other insects several studies have highlighted an essential role for the exo-RNAi pathway in combating viral infection. Here, by using deep-sequencing technology for viral small-RNA (vsRNA) assessment, we provide evidence that exo-RNAi is operative in the silkworm Bombyx mori against both persistent and pathogenic infection of B. mori cytoplasmic polyhedrosis virus (BmCPV) which is characterized by...

Nanoparticulate anatase TiO2 (TiO2 NPs) upregulates the expression of silkworm (Bombyx mori) neuropeptide receptor and promotes silkworm feeding, growth, and silking.

Science.gov (United States)

Ni, Min; Zhang, Hua; Li, Fan Chi; Wang, Bin Bin; Xu, Kai Zun; Shen, Wei De; Li, Bing

2015-06-01

Bombyx mori orphan G protein-coupled receptor, BNGR-A4, is the specific receptor of B. mori neuropeptide F (BmNPFR, neuropeptide F designated NPF). BmNPFR binds specifically and efficiently to B. mori neuropeptides BmNPF1a and BmNPF1b, which activates the ERK1/2 signaling pathway to regulate B. mori food intake and growth. Titanium dioxide nanoparticles (TiO2 NPs) can promote B. mori growth. However, whether the mechanisms of TiO2 NPs' effects are correlated with BmNPFR remains unknown. In this study, the effects of TiO2 NPs (5mg/L) feeding and BmNPFR-dsRNA injection on B. mori food intake and growth were investigated; after TiO2 NPs treatments, B. mori food intake, body weight, and cocoon shell weight were 5.82%, 4.64%, and 9.30% higher, respectively, than those of controls. The food intake, body weight, and cocoon shell weight of the BmNPFR-dsRNA injection group were reduced by 8.05%, 6.28%, and 6.98%, respectively, compared to the control. After TiO2 NPs treatment for 72h, the transcriptional levels of BmNPFR, BmNPF1a, and BmNPF1b in the midgut were 1.58, 1.43, and 1.34-folds, respectively, of those of the control, but 1.99, 2.26, and 2.19-folds, respectively, of the BmNPFR-dsRNA injection group; the phosphorylation level of MAPK was 24.03% higher than the control, while the phosphorylation level of BmNPFR-dsRNA injection group was 71.00% of control. The results indicated that TiO2 NPs affect B. mori feeding and growth through increasing the expression of BmNPFR. This study helps clarify the roles of BmNPF/BmNPFR system in TiO2 NPs' effects on B. mori feeding, growth, and development. Copyright © 2015 Elsevier Inc. All rights reserved.

Binding specificity of Bacillus thuringiensis Cry1Aa for purified, native Bombyx mori aminopeptidase N and cadherin-like receptors

Directory of Open Access Journals (Sweden)

Jenkins Jeremy L

2001-10-01

Full Text Available Abstract Background To better understand the molecular interactions of Bt toxins with non-target insects, we have examined the real-time binding specificity and affinity of Cry1 toxins to native silkworm (Bombyx mori midgut receptors. Previous studies on B. mori receptors utilized brush border membrane vesicles or purifed receptors in blot-type assays. Results The Bombyx mori (silkworm aminopeptidase N (APN and cadherin-like receptors for Bacillus thuringiensis insecticidal Cry1Aa toxin were purified and their real-time binding affinities for Cry toxins were examined by surface plasmon resonance. Cry1Ab and Cry1Ac toxins did not bind to the immobilized native receptors, correlating with their low toxicities. Cry1Aa displayed moderate affinity for B. mori APN (75 nM, and unusually tight binding to the cadherin-like receptor (2.6 nM, which results from slow dissociation rates. The binding of a hybrid toxin (Aa/Aa/Ac was identical to Cry1Aa. Conclusions These results indicate domain II of Cry1Aa is essential for binding to native B. mori receptors and for toxicity. Moreover, the high-affinity binding of Cry1Aa to native cadherin-like receptor emphasizes the importance of this receptor class for Bt toxin research.

Binding specificity of Bacillus thuringiensis Cry1Aa for purified, native Bombyx mori aminopeptidase N and cadherin-like receptors

Science.gov (United States)

Jenkins, Jeremy L; Dean, Donald H

2001-01-01

Background To better understand the molecular interactions of Bt toxins with non-target insects, we have examined the real-time binding specificity and affinity of Cry1 toxins to native silkworm (Bombyx mori) midgut receptors. Previous studies on B. mori receptors utilized brush border membrane vesicles or purifed receptors in blot-type assays. Results The Bombyx mori (silkworm) aminopeptidase N (APN) and cadherin-like receptors for Bacillus thuringiensis insecticidal Cry1Aa toxin were purified and their real-time binding affinities for Cry toxins were examined by surface plasmon resonance. Cry1Ab and Cry1Ac toxins did not bind to the immobilized native receptors, correlating with their low toxicities. Cry1Aa displayed moderate affinity for B. mori APN (75 nM), and unusually tight binding to the cadherin-like receptor (2.6 nM), which results from slow dissociation rates. The binding of a hybrid toxin (Aa/Aa/Ac) was identical to Cry1Aa. Conclusions These results indicate domain II of Cry1Aa is essential for binding to native B. mori receptors and for toxicity. Moreover, the high-affinity binding of Cry1Aa to native cadherin-like receptor emphasizes the importance of this receptor class for Bt toxin research. PMID:11722800

Thermally Induced Alpha-Helix to Beta-Sheet Transition in Regenerated Silk Fibers and Films

Energy Technology Data Exchange (ETDEWEB)

Drummy,L.; Phillips, D.; Stone, M.; Farmer, B.; Naik, R.

2005-01-01

The structure of thin films cast from regenerated solutions of Bombyx mori cocoon silk in hexafluoroisopropyl alcohol (HFIP) was studied by synchrotron X-ray diffraction during heating. A solid-state conformational transition from an alpha-helical structure to the well-known beta-sheet silk II structure occurred at a temperature of approximately 140 degrees C. The transition appeared to be homogeneous, as both phases do not coexist within the resolution of the current study. Modulated differential scanning calorimetry (DSC) of the films showed an endothermic melting peak followed by an exothermic crystallization peak, both occurring near 140 degrees C. Oriented fibers were also produced that displayed this helical molecular conformation. Subsequent heating above the structural transition temperature produced oriented beta-sheet fibers very similar in structure to B. mori cocoon fibers. Heat treatment of silk films at temperatures well below their degradation temperature offers a controllable route to materials with well-defined structures and mechanical behavior.

Bombyx mori E26 transformation-specific 2 (BmEts2), an Ets family protein, represses Bombyx mori Rels (BmRels)-mediated promoter activation of antimicrobial peptide genes in the silkworm Bombyx mori.

Science.gov (United States)

Tanaka, H; Sagisaka, A; Suzuki, N; Yamakawa, M

2016-10-01

E26 transformation-specific (Ets) family transcription factors are known to play roles in various biological phenomena, including immunity, in vertebrates. However, the mechanisms by which Ets proteins contribute to immunity in invertebrates remain poorly understood. In this study, we identified a cDNA encoding BmEts2, which is a putative orthologue of Drosophila Yan and human translocation-ets-leukemia/Ets-variant gene 6, from the silkworm Bombyx mori. Expression of the BmEts2 gene was significantly increased in the fat bodies of silkworm larvae in response to injection with Escherichia coli and Staphylococcus aureus. BmEts2 overexpression dramatically repressed B. mori Rels (BmRels)-mediated promoter activation of antimicrobial peptide genes in silkworm cells. Conversely, gene knockdown of BmEts2 significantly enhanced BmRels activity. In addition, two κB sites located on the 5' upstream region of cecropin B1 were found to be involved in the repression of BmRels-mediated promoter activation. Protein-competition analysis further demonstrated that BmEts2 competitively inhibited binding of BmRels to κB sites. Overall, BmEts2 acts as a repressor of BmRels-mediated transactivation of antimicrobial protein genes by inhibiting the binding of BmRels to κB sites. © 2016 The Royal Entomological Society.

MicroRNA of the fifth-instar posterior silk gland of silkworm identified by Solexa sequencing

Directory of Open Access Journals (Sweden)

Jisheng Li

2014-12-01

Full Text Available No special studies have been focused on the microRNA (miRNA in the fifth-instar posterior silk gland of Bombyx mori. Here, using next-generation sequencing, we acquired 93.2 million processed reads from 10 small RNA libraries. In this paper, we tried to thoroughly describe how our dataset generated from deep sequencing which was recently published in BMC genomics. Results showed that our findings are largely enriched silkworm miRNA depository and may benefit us to reveal the miRNA functions in the process of silk production.

Silkworm (Bombyx mori) hemocytes do not produce reactive oxygen metabolites as a part of defense mechanisms

Czech Academy of Sciences Publication Activity Database

Hyršl, P.; Číž, Milan; Kubala, Lukáš; Lojek, Antonín

2004-01-01

Roč. 49, č. 3 (2004), s. 315-319 ISSN 0015-5632 R&D Projects: GA AV ČR IBS5004009 Institutional research plan: CEZ:AV0Z5004920 Keywords : hemocytes * Bombyx mori * reactive oxygen species Subject RIV: BO - Biophysics Impact factor: 1.034, year: 2004

COCOON PRODUCTION OF THE SILKWORM, Bombyx mori L. (LEPIDOPTERA: BOMBYCIDAE, FED ON LEAVES OF MULBERRY HYBRIDS

Directory of Open Access Journals (Sweden)

GERBSON AZEVEDO DE MENDONÇA

2010-01-01

Full Text Available Brazil is the fourth cocoon producer in the world. In São Paulo State there are mulberry some hybrids whose productivity are higher than the commonly cultivated varieties. The objective of this study was to evaluate the effect of mulberry hybrids (Morus spp. on the cocoon production of silkworm (Bombyx mori L.. The experiment was conducted at the Unidade Regional de Pesquisa de Gália do Instituto de Zootecnia, SP. The caterpillars were fed on leaves of the hybrids IZ-3/2, IZ-13/6, IZ-15/7, IZ-19/13, IZ-56/4, IZ-57/2, IZ- 40, IZ-64, in a rearing hut at 25 oC ± 3 oC and 75% ± 5% relative humidity. 'Korin' was used as standard. The hybrids affected the duration of the larval period and the weight of the caterpillars, prepupaes and the silk glands as well. There was a reduction in the duration of larval development when the caterpillars had been fed with hybrid IZ-56/4 and the 'Korin' variety. Hybrids IZ-57/2, IZ-56/4 and IZ-15/7 presented the highest cocoon production.

A novel immune-related gene HDD1 of silkworm Bombyx mori is involved in bacterial response.

Science.gov (United States)

Zhang, Kui; Pan, Guangzhao; Zhao, Yuzu; Hao, Xiangwei; Li, Chongyang; Shen, Li; Zhang, Rui; Su, Jingjing; Cui, Hongjuan

2017-08-01

Insects have evolved an effective immune system to respond to various challenges. In this study, a novel immune-related gene, called BmHDD1, was first charactered in silkworm, Bombyx mori. BmHDD1 contained an ORF of 837bp and encoding a deduced protein of 278 amino acids. BmHDD1 was specifically expressed in hemocytes, and highly expressed at the molting and metamorphosis stages under normal physiological conditions. Our results suggested that BmHDD1 was mainly generated by hemocytes and secreted into hemolymph. Our results also showed that the expression level of BmHDD1 was significantly increased after 20E injection, which indicated that BmHDD1 might be regulated by ecdysone. More importantly, BmHDD1 was dramatically induced after injected with different types of PAMPs or bacteria, either in hemocytes or fat body. Those results suggested that BmHDD1 plays a role in developing and immunity system in silkworm, Bombyx mori. Copyright © 2017. Published by Elsevier Ltd.

Sublethal dose of phoxim and Bombyx mori nucleopolyhedrovirus interact to elevate silkworm mortality.

Science.gov (United States)

Gu, ZhiYa; Li, FanChi; Hu, JingSheng; Ding, Chao; Wang, Chaoqian; Tian, JiangHai; Xue, Bin; Xu, KaiZun; Shen, WeiDe; Li, Bing

2017-03-01

Silkworm (Bombyx mori) is an economically important insect. It is relatively less resistant to certain chemicals and environment exposures such as pesticides and pathogens. After pesticide exposures, the silkworms are more susceptible to microbial infections. The mechanism underlying the susceptibility might be related to immune response and oxidative stress. A sublethal dose of phoxim combined with Bombyx mori nucleopolyhedrovirus (BmNPV) elevated the silkworm mortality at 96 h. We found a higher content of H 2 O 2 and increased levels of genes related to oxidative stress and immune response after treatment with a sublethal dose of phoxim for 24 h or 48 h. However, such response decreased with longer pesticide treatment. Mortality increased by 44% when B. mori was exposed to combined treatment with BmNPV and phoxim rather than BmNPV alone. The level of examined immune-related and oxidative-stress-related genes significantly decreased in the combined treatment group compared with the BmNPV group. Our results indicated that, with long-term exposure to pesticides such as OPs, even at sublethal dose, the oxidative stress response and immune responses in silkworm were inhibited, which may lead to further immune impairment and accumulation of oxidative stress, resulting in susceptibility to the virus and harm to the silkworm. Our study provided insights for understanding the susceptibility to pathogen after pesticide exposures, which may promote the development of better pesticide controls to avoid significant economic losses. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

Development of a standard acute dietary toxicity test for the silkworm (Bombyx mori L.)

NARCIS (Netherlands)

Sun, X.; Valk, H.; Jiang, H.; Wang, X.; Yuan, S.; Zhang, Y.; Roessink, I.; Gao, X.

2012-01-01

Larvae of the silkworm (Bombyx mod L.) may be exposed to pesticide residues on the leaves of their food plant, the mulberry tree (Morus spp.), which can lead to adverse effects on silk production. A new acute dietary toxicity test method was evaluated as the basis for pesticide risk assessment. A

Effects of Ag Nanoparticles on Growth and Fat Body Proteins in Silkworms (Bombyx mori).

Science.gov (United States)

Meng, Xu; Abdlli, Nouara; Wang, Niannian; Lü, Peng; Nie, Zhichao; Dong, Xin; Lu, Shuang; Chen, Keping

2017-12-01

Ag nanoparticles (AgNPs), a widely used non-antibiotic, antibacterial material, have shown toxic and other potentially harmful effects in mammals. However, the deleterious effects of AgNPs on insects are still unknown. Here, we studied the effects of AgNPs on the model invertebrate organism Bombyx mori. After feeding silkworm larvae different concentrations of AgNPs, we evaluated the changes of B. mori body weights, survival rates, and proteomic differences. The results showed that low concentrations (mori. Although high concentrations (≥800 mg/L) of AgNPs also improved B. mori growth, they resulted in silkworm death. An analysis of fat body proteomic differences revealed 13 significant differences in fat body protein spots, nine of which exhibited significantly downregulated expression, while four showed significantly upregulated expression. Reverse transcription-polymerase chain reaction results showed that at an AgNP concentration of 1600 mg/L, the expression levels of seven proteins were similar to the transcription levels of their corresponding genes. Our results suggest that AgNPs lowered the resistance to oxidative stress, affected cell apoptosis, and induced cell necrosis by regulating related protein metabolism and metabolic pathways in B. mori.

Identification and analysis of YELLOW protein family genes in the silkworm, Bombyx mori

Directory of Open Access Journals (Sweden)

Yi Yong-Zhu

2006-08-01

Full Text Available Abstract Background The major royal jelly proteins/yellow (MRJP/YELLOW family possesses several physiological and chemical functions in the development of Apis mellifera and Drosophila melanogaster. Each protein of the family has a conserved domain named MRJP. However, there is no report of MRJP/YELLOW family proteins in the Lepidoptera. Results Using the YELLOW protein sequence in Drosophila melanogaster to BLAST silkworm EST database, we found a gene family composed of seven members with a conserved MRJP domain each and named it YELLOW protein family of Bombyx mori. We completed the cDNA sequences with RACE method. The protein of each member possesses a MRJP domain and a putative cleavable signal peptide consisting of a hydrophobic sequence. In view of genetic evolution, the whole Bm YELLOW protein family composes a monophyletic group, which is distinctly separate from Drosophila melanogaster and Apis mellifera. We then showed the tissue expression profiles of Bm YELLOW protein family genes by RT-PCR. Conclusion A Bombyx mori YELLOW protein family is found to be composed of at least seven members. The low homogeneity and unique pattern of gene expression by each member among the family ensure us to prophesy that the members of Bm YELLOW protein family would play some important physiological functions in silkworm development.

A User’s Manual for Fiber Diffraction: The Automated Picker and Huber Diffractometers

Science.gov (United States)

1990-07-01

17 3. Layer line scan of degummed silk ( Bombyx mori ) ................................. 18...index (arbitrary units) Figure 3. Layer line scan of degummed silk ( Bombyx mori ) showing layers 0 through 6. If the fit is rejected, new values for... originally made at intervals larger than 0.010. The smoothing and interpolation is done by a least-squares polynomial fit to segments of the data. The number

Hygroscopics and yield characteristics of cocoon in races of Bombyx mori L.

OpenAIRE

Antonio José Porto; José Eduardo de Almeida

2012-01-01

Cocoons, cocoon shells and chrysalis of four races of Bombyx mori L., two from China (C202 and C212) and two from Japan (B104 and M11-2), were analyzed in function of determinant factors as weight (dry mater and moisture) and by hygroscopic capacity after cooking. It was used a complete randomized design, with four treatments and ten replications. Although the cocoon shell has a higher hygroscopic capacity, the percentage of water in the chrysalis is the main factor to determine the weight of...

Genomic diversity of Bombyx mori nucleopolyhedrovirus strains.

Science.gov (United States)

Xu, Yi-Peng; Cheng, Ruo-Lin; Xi, Yu; Zhang, Chuan-Xi

2013-07-01

Bombyx mori nucleopolyhedrovirus (BmNPV) is a baculovirus that selectively infects the domestic silkworm. In this study, six BmNPV strains were compared at the whole genome level. We found that the number of bro genes and the composition of the homologous regions (hrs) are the two primary areas of divergence within these genomes. When we compared the ORFs of these BmNPV variants, we noticed a high degree of sequence divergence in the ORFs that are not baculovirus core genes. This result is consistent with the results derived from phylogenetic trees and evolutionary pressure analyses of these ORFs, indicating that ORFs that are not core genes likely play important roles in the evolution of BmNPV strains. The evolutionary relationships of these BmNPV strains might be explained by their geographic origins or those of their hosts. In addition, the total number of hr palindromes seems to affect viral DNA replication in Bm5 cells. Copyright © 2013 Elsevier Inc. All rights reserved.

Metal nanoparticles triggered persistent negative photoconductivity in silk protein hydrogels

Science.gov (United States)

Gogurla, Narendar; Sinha, Arun K.; Naskar, Deboki; Kundu, Subhas C.; Ray, Samit K.

2016-03-01

Silk protein is a natural biopolymer with intriguing properties, which are attractive for next generation bio-integrated electronic and photonic devices. Here, we demonstrate the negative photoconductive response of Bombyx mori silk protein fibroin hydrogels, triggered by Au nanoparticles. The room temperature electrical conductivity of Au-silk hydrogels is found to be enhanced with the incorporation of Au nanoparticles over the control sample, due to the increased charge transporting networks within the hydrogel. Au-silk lateral photoconductor devices show a unique negative photoconductive response under an illumination of 325 nm, with excitation energy higher than the characteristic metal plasmon resonance band. The enhanced photoconductance yield in the hydrogels over the silk protein is attributed to the photo-oxidation of amino groups in the β-pleated sheets of the silk around the Au nanoparticles followed by the breaking of charge transport networks. The Au-silk nanocomposite does not show any photoresponse under visible illumination because of the localization of excited charges in Au nanoparticles. The negative photoconductive response of hybrid Au-silk under UV illumination may pave the way towards the utilization of silk for future bio-photonic devices using metal nanoparticle platforms.

MicroRNA expression profiling during the life cycle of the silkworm (Bombyx mori)

OpenAIRE

Liu, Shiping; Zhang, Liang; Li, Qibin; Zhao, Ping; Duan, Jun; Cheng, Daojun; Xiang, Zhonghuai; Xia, Qingyou

2009-01-01

Abstract Background MicroRNAs (miRNAs) are expressed by a wide range of eukaryotic organisms, and function in diverse biological processes. Numerous miRNAs have been identified in Bombyx mori, but the temporal expression profiles of miRNAs corresponding to each stage transition over the entire life cycle of the silkworm remain to be established. To obtain a comprehensive overview of the correlation between miRNA expression and stage transitions, we performed a whole-life test and subsequent s...

Invited review nonmulberry silk biopolymers.

Science.gov (United States)

Kundu, S C; Kundu, Banani; Talukdar, Sarmistha; Bano, Subia; Nayak, Sunita; Kundu, Joydip; Mandal, Biman B; Bhardwaj, Nandana; Botlagunta, Mahendran; Dash, Biraja C; Acharya, Chitrangada; Ghosh, Ananta K

2012-06-01

The silk produced by silkworms are biopolymers and can be classified into two types--mulberry and nonmulberry. Mulberry silk of silkworm Bombyx mori has been extensively explored and used for century old textiles and sutures. But for the last few decades it is being extensively exploited for biomedical applications. However, the transformation of nonmulberry silk from being a textile commodity to biomaterials is relatively new. Within a very short period of time, the combination of load bearing capability and tensile strength of nonmulberry silk has been equally envisioned for bone, cartilage, adipose, and other tissue regeneration. Adding to its advantage is its diverse morphology, including macro to nano architectures with controllable degradation and biocompatibility yields novel natural material systems in vitro. Its follow on applications involve sustained release of model compounds and anticancer drugs. Its 3D cancer models provide compatible microenvironment systems for better understanding of the cancer progression mechanism and screening of anticancer compounds. Diversely designed nonmulberry matrices thus provide an array of new cutting age technologies, which is unattainable with the current synthetic materials that lack biodegradability and biocompatibility. Scientific exploration of nonmulberry silk in tissue engineering, regenerative medicine, and biotechnological applications promises advancement of sericulture industries in India and China, largest nonmulberry silk producers of the world. This review discusses the prospective biomedical applications of nonmulberry silk proteins as natural biomaterials. Copyright © 2012 Wiley Periodicals, Inc.

Antiviral activity of a serine protease from the digestive juice of Bombyx mori larvae against nucleopolyhedrovirus

International Nuclear Information System (INIS)

Nakazawa, Hiroshi; Tsuneishi, Eiko; Ponnuvel, Kangayam M.; Furukawa, Seiichi; Asaoka, Ai; Tanaka, Hiromitsu; Ishibashi, Jun; Yamakawa, Minoru

2004-01-01

A protein showing strong antiviral activity against Bombyx mori nucleopolyhedrovirus (BmNPV) was purified from the digestive juice of B. mori larvae. The molecular mass of this protein was 24 271 Da. Partial N-terminal amino acid sequence of the protein was determined and cDNA was cloned based on the amino acid sequence. A homology search of the deduced amino acid sequence of the cDNA showed 94% identity with B. mori serine protease so the protein was designated B. mori serine protease-2 (BmSP-2). Analysis of BmSP-2 gene expression showed that this gene is expressed in the midgut but not in other tissues. In addition, BmSP-2 gene was shown to not be expressed in the molting and wandering stages, indicating that the gene is hormonally regulated. Our results suggest that BmSP-2, an insect digestive enzyme, can be a potential antiviral factor against BmNPV at the initial site of viral infection

Induction of thermal shock proteins and changes in radiosensitivity after heat treatment of Bombyx mori L. embryos

International Nuclear Information System (INIS)

Agaev, F.A.

1993-01-01

The method of gel-electrophoresis was used to study thermal shock protein synthesis in Bombyx mori embryos exposed to a mixture of heat and gamma-radiation. Induction of thermal shock protein synthesis was not inhibited by gamma-radiation. It is suggested that thermal shock proteins are involved embryo radiosensitivity modification

The Rheology behind Stress-Induced Solidification in Native Silk Feedstocks.

Science.gov (United States)

Laity, Peter R; Holland, Chris

2016-10-29

The mechanism by which native silk feedstocks are converted to solid fibres in nature has attracted much interest. To address this question, the present work used rheology to investigate the gelation of Bombyx mori native silk feedstock. Exceeding a critical shear stress appeared to be more important than shear rate, during flow-induced initiation. Compositional changes (salts, pH etc.,) were not required, although their possible role in vivo is not excluded. Moreover, after successful initiation, gel strength continued to increase over a considerable time under effectively quiescent conditions, without requiring further application of the initial stimulus. Gelation by elevated temperature or freezing was also observed. Prior to gelation, literature suggests that silk protein adopts a random coil configuration, which argued against the conventional explanation of gelation, based on hydrophilic and hydrophobic interactions. Instead, a new hypothesis is presented, based on entropically-driven loss of hydration, which appears to explain the apparently diverse methods by which silk feedstocks can be gelled.

The Rheology behind Stress-Induced Solidification in Native Silk Feedstocks

Directory of Open Access Journals (Sweden)

Peter R. Laity

2016-10-01

Full Text Available The mechanism by which native silk feedstocks are converted to solid fibres in nature has attracted much interest. To address this question, the present work used rheology to investigate the gelation of Bombyx mori native silk feedstock. Exceeding a critical shear stress appeared to be more important than shear rate, during flow-induced initiation. Compositional changes (salts, pH etc., were not required, although their possible role in vivo is not excluded. Moreover, after successful initiation, gel strength continued to increase over a considerable time under effectively quiescent conditions, without requiring further application of the initial stimulus. Gelation by elevated temperature or freezing was also observed. Prior to gelation, literature suggests that silk protein adopts a random coil configuration, which argued against the conventional explanation of gelation, based on hydrophilic and hydrophobic interactions. Instead, a new hypothesis is presented, based on entropically-driven loss of hydration, which appears to explain the apparently diverse methods by which silk feedstocks can be gelled.

Native Silk Feedstock as a Model Biopolymer: A Rheological Perspective.

Science.gov (United States)

Laity, Peter R; Holland, Chris

2016-08-08

Variability in silk's rheology is often regarded as an impediment to understanding or successfully copying the natural spinning process. We have previously reported such variability in unspun native silk extracted straight from the gland of the domesticated silkworm Bombyx mori and discounted classical explanations such as differences in molecular weight and concentration. We now report that variability in oscillatory measurements can be reduced onto a simple master-curve through normalizing with respect to the crossover. This remarkable result suggests that differences between silk feedstocks are rheologically simple and not as complex as originally thought. By comparison, solutions of poly(ethylene-oxide) and hydroxypropyl-methyl-cellulose showed similar normalization behavior; however, the resulting curves were broader than for silk, suggesting greater polydispersity in the (semi)synthetic materials. Thus, we conclude Nature may in fact produce polymer feedstocks that are more consistent than typical man-made counterparts as a model for future rheological investigations.

Improved human tenocyte proliferation and differentiation in vitro by optimized silk degumming

Energy Technology Data Exchange (ETDEWEB)

Wang Xiao; Qiu Yiwei; Carr, Andrew J; Triffitt, James T; Sabokbar, Afsie; Xia Zhidao, E-mail: z.xia@swansea.ac.uk [Botnar Research Centre, Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, University of Oxford, Oxford (United Kingdom)

2011-06-15

Tendon disorders are common clinical conditions. Tendon tissue engineering provides a new approach for tendon repair by integrating engineered substitutes with their native counterparts. Silk is considered to be a promising candidate for tendon engineering because of its biological and mechanical properties. However, a major concern with using silk for biomedical applications is the immune responses generated by sericin, a glue-like protein that coats the silk fibres. This study improves the existing protocols for silk 'degumming' which removes sericin and enables preparation of silk that is suitable for tendon regeneration. Bombyx mori silks were treated by sequential treatments with different proteases. The efficiency of degumming was determined by measuring weight loss, picric acid and carmine staining and scanning electron microscopy. To evaluate the cellular responses after degumming, the growth and differentiation of human tenocytes on silks were examined. The results showed that sequential protease treatment effectively degummed raw silks. The sequentially degummed silks showed enhanced tenocyte proliferation and upregulated mRNA levels of tendon markers. Thick cell multilayers formed on the treated silks, with cells and collagen fibres penetrating into the spaces in individual silk filaments, resulting in a structure resembling human tendon.

Improved human tenocyte proliferation and differentiation in vitro by optimized silk degumming

Energy Technology Data Exchange (ETDEWEB)

Xiao, Wang; Yiwei, Qiu; Carr, Andrew J; Triffitt, James T; Sabokbar, Afsie; Xia Zhidao, E-mail: z.xia@swansea.ac.uk [Botnar Research Centre, Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, University of Oxford, Oxford (United Kingdom)

2011-06-15

Tendon disorders are common clinical conditions. Tendon tissue engineering provides a new approach for tendon repair by integrating engineered substitutes with their native counterparts. Silk is considered to be a promising candidate for tendon engineering because of its biological and mechanical properties. However, a major concern with using silk for biomedical applications is the immune responses generated by sericin, a glue-like protein that coats the silk fibres. This study improves the existing protocols for silk 'degumming' which removes sericin and enables preparation of silk that is suitable for tendon regeneration. Bombyx mori silks were treated by sequential treatments with different proteases. The efficiency of degumming was determined by measuring weight loss, picric acid and carmine staining and scanning electron microscopy. To evaluate the cellular responses after degumming, the growth and differentiation of human tenocytes on silks were examined. The results showed that sequential protease treatment effectively degummed raw silks. The sequentially degummed silks showed enhanced tenocyte proliferation and upregulated mRNA levels of tendon markers. Thick cell multilayers formed on the treated silks, with cells and collagen fibres penetrating into the spaces in individual silk filaments, resulting in a structure resembling human tendon.

Resistance to BmNPV via overexpression of an exogenous gene controlled by an inducible promoter and enhancer in transgenic silkworm, Bombyx mori.

Directory of Open Access Journals (Sweden)

Liang Jiang

Full Text Available The hycu-ep32 gene of Hyphantria cunea NPV can inhibit Bombyx mori nucleopolyhedrovirus (BmNPV multiplication in co-infected cells, but it is not known whether the overexpression of the hycu-ep32 gene has an antiviral effect in the silkworm, Bombyx mori. Thus, we constructed four transgenic vectors, which were under the control of the 39 K promoter of BmNPV (39 KP, Bombyx mori A4 promoter (A4P, hr3 enhancer of BmNPV combined with 39 KP, and hr3 combined with A4P. Transgenic lines were created via embryo microinjection using practical diapause silkworm. qPCR revealed that the expression level of hycu-ep32 could be induced effectively after BmNPV infection in transgenic lines where hycu-ep32 was controlled by hr3 combined with 39 KP (i.e., HEKG. After oral inoculation of BmNPV with 3 × 10(5 occlusion bodies per third instar, the mortality with HEKG-B was approximately 30% lower compared with the non-transgenic line. The economic characteristics of the transgenic lines remained unchanged. These results suggest that overexpression of an exogenous antiviral gene controlled by an inducible promoter and enhancer is a feasible method for breeding silkworms with a high antiviral capacity.

Silk: a potential medium for tissue engineering.

Science.gov (United States)

Sobajo, Cassandra; Behzad, Farhad; Yuan, Xue-Feng; Bayat, Ardeshir

2008-01-01

Human skin is a complex bilayered organ that serves as a protective barrier against the environment. The loss of integrity of skin by traumatic experiences such as burns and ulcers may result in considerable disability or ultimately death. Therefore, in skin injuries, adequate dermal substitutes are among primary care targets, aimed at replacing the structural and functional properties of native skin. To date, there are very few single application tissue-engineered dermal constructs fulfilling this criterion. Silk produced by the domestic silkworm, Bombyx mori, has a long history of use in medicine. It has recently been increasingly investigated as a promising biomaterial for dermal constructs. Silk contains 2 fibrous proteins, sericin and fibroin. Each one exhibits unique mechanical and biological properties. Comprehensive review of randomized-controlled trials investigating current dermal constructs and the structures and properties of silk-based constructs on wound healing. This review revealed that silk-fibroin is regarded as the most promising biomaterial, providing options for the construction of tissue-engineered skin. The research available indicates that silk fibroin is a suitable biomaterial scaffold for the provision of adequate dermal constructs.

Sialylation potentials of the silkworm, Bombyx mori; B. mori possesses an active α2,6-sialyltransferase.

Science.gov (United States)

Kajiura, Hiroyuki; Hamaguchi, Yuichi; Mizushima, Hiroki; Misaki, Ryo; Fujiyama, Kazuhito

2015-12-01

N-Glycosylation is an important post-translational modification in most secreted and membrane-bound proteins in eukaryotic cells. However, the insect N-glycosylation pathway and the potentials contributing to the N-glycan synthesis are still unclear because most of the studies on these subjects have focused on mammals and plants. Here, we identified Bombyx mori sialyltransferase (BmST), which is a Golgi-localized glycosyltransferase and which can modify N-glycans. BmST was ubiquitously expressed in different organs and in various stages of development and localized at the Golgi. Biochemical analysis using Sf9-expressed BmST revealed that BmST encoded α2,6-sialyltransferase and transferred N-acetylneuraminic acid (NeuAc) to the nonreducing terminus of Galβ1-R, but exhibited the highest activity toward GalNAcβ1,4-GlcNAc-R. Unlike human α2,6-sialyltransferase, BmST required the post-translational modification, especially N-glycosylation, for its full activity. N-Glycoprotein analysis of B. mori fifth instar larvae revealed that high-mannose-type structure was predominant and GlcNAc-linked and fucosylated structures were observed but endogenous galactosyl-, N-acetylgalactosaminyl- and sialyl-N-glycoproteins were undetectable under the standard analytical approach. These results indicate that B. mori genome encodes an α2,6-sialyltransferase, but further investigations of the sialylation potentials are necessary. © The Author 2015. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Protective effects of Bombyx mori, quercetin and benazepril against doxorubicin induced cardiotoxicity and nephrotoxicity

Directory of Open Access Journals (Sweden)

Abdul S. Nazmi

2016-09-01

Full Text Available The present study was conducted with the aim of evaluating the protective effects of Bombyx mori, quercetin and benazepril on doxorubicin (DXR induced cardiotoxicity and nephrotoxicity in rats. B. mori, quercetin and benazepril were administered for 7 days, and a single intravenous injection of 10 mg/kg body weight of DXR on day five. The animals were sacrificed 48 h after DXR administration. DXR produced a significant elevation in the malondialdehyde (MDA level and significantly inhibited the activity of glutathione (GSH in the heart and the kidney followed by the activity of catalase (CAT in the heart tissue with a significant rise in the serum levels of aspartate transaminase (AST, lactate dehydrogenase (LDH, blood urea nitrogen (BUN, creatinine and a reduction in serum GSH levels indicating acute cardiac toxicity. B. mori, quercetin and benazepril pretreatment significantly reduced the MDA concentration and ameliorated the inhibition of cardiac GSH and CAT activity. B. mori, quercetin and benazepril also significantly improved the serum levels of AST, LDH, BUN, creatinine and GSH in DXR-treated rats. Furthermore, histological examination of the heart sections confirmed the myocardial injury with DXR administration, and the near normal pattern with B. mori, quercetin and benazepril pretreatment. The results provide clear evidence that the B. mori, quercetin and benazepril pretreatments offer significant protection against DXR-induced enzymatic changes in serum, cardiac and renal tissue damage.

Proteome identification of the silkworm middle silk gland

Directory of Open Access Journals (Sweden)

Jian-ying Li

2016-03-01

Full Text Available To investigate the functional differentiation among the anterior (A, middle (M, and posterior (P regions of silkworm middle silk gland (MSG, their proteomes were characterized by shotgun LC–MS/MS analysis with a LTQ-Orbitrap mass spectrometer. To get better proteome identification and quantification, triplicate replicates of mass spectrometry analysis were performed for each sample. The mass spectrometry proteomics data have been deposited to the ProteomeXchange Consortium (Vizcaíno et al., 2014 [1] via the PRIDE partner repository (Vizcaino, 2013 [2] with the dataset identifier http://www.ebi.ac.uk/pride/archive/projects/PXD003371. The peptide identifications that were further processed by PeptideProphet program in Trans-Proteomic Pipeline (TPP after database search with Mascot software were also available in .XML format files. Data presented here are related to a research article published in Journal of Proteomics by Li et al. (2015 [3]. Keywords: Bombyx mori, Middle silk gland, Silk protein synthesis, Shotgun proteomics, Label-free

An integrated CRISPR Bombyx mori genome editing system with improved efficiency and expanded target sites.

Science.gov (United States)

Ma, Sanyuan; Liu, Yue; Liu, Yuanyuan; Chang, Jiasong; Zhang, Tong; Wang, Xiaogang; Shi, Run; Lu, Wei; Xia, Xiaojuan; Zhao, Ping; Xia, Qingyou

2017-04-01

Genome editing enabled unprecedented new opportunities for targeted genomic engineering of a wide variety of organisms ranging from microbes, plants, animals and even human embryos. The serial establishing and rapid applications of genome editing tools significantly accelerated Bombyx mori (B. mori) research during the past years. However, the only CRISPR system in B. mori was the commonly used SpCas9, which only recognize target sites containing NGG PAM sequence. In the present study, we first improve the efficiency of our previous established SpCas9 system by 3.5 folds. The improved high efficiency was also observed at several loci in both BmNs cells and B. mori embryos. Then to expand the target sites, we showed that two newly discovered CRISPR system, SaCas9 and AsCpf1, could also induce highly efficient site-specific genome editing in BmNs cells, and constructed an integrated CRISPR system. Genome-wide analysis of targetable sites was further conducted and showed that the integrated system cover 69,144,399 sites in B. mori genome, and one site could be found in every 6.5 bp. The efficiency and resolution of this CRISPR platform will probably accelerate both fundamental researches and applicable studies in B. mori, and perhaps other insects. Copyright © 2017 Elsevier Ltd. All rights reserved.

Rab proteins in the brain and corpus allatum of Bombyx mori.

Science.gov (United States)

Uno, Tomohide; Furutani, Masayuki; Watanabe, Chihiro; Sakamoto, Katsuhiko; Uno, Yuichi; Kanamaru, Kengo; Yamagata, Hiroshi; Mizoguchi, Akira; Takeda, Makio

2016-07-01

In eukaryotic cells, Rab guanosine triphosphate-ases serve as key regulators of membrane-trafficking events, such as exocytosis and endocytosis. Rab3, Rab6, and Rab27 control the regulatory secretory pathway of neuropeptides and neurotransmitters. The cDNAs of Rab3, Rab6, and Rab27 from B. mori were inserted into a plasmid, transformed into Escherichia coli, and then subsequently purified. We then produced antibodies against Rab3, Rab6, and Rab27 of Bombyx mori in rabbits and rats for use in western immunoblotting and immunohistochemistry. Western immunoblotting of brain tissue revealed a single band at approximately 26 kDa. Immunohistochemistry results revealed that Rab3, Rab6, and Rab27 expression was restricted to neurons in the pars intercerebralis and dorsolateral protocerebrum of the brain. Rab3 and Rab6 co-localized with bombyxin, an insect neuropeptide. However, there was no Rab that co-localized with prothoracicotropic hormone. The corpus allatum secretes neuropeptides synthesized in the brain into the hemolymph. Results showed that Rab3 and Rab6 co-localized with bombyxin in the corpus allatum. These findings suggest that Rab3 and Rab6 are involved in neurosecretion in B. mori. This study is the first to report a possible relationship between Rab and neurosecretion in the insect corpus allatum.

Juvenile Hormone Analogues, Methoprene and Fenoxycarb Dose-Dependently Enhance Certain Enzyme Activities in the Silkworm Bombyx Mori (L

Directory of Open Access Journals (Sweden)

M. Rajeswara Rao

2008-06-01

Full Text Available Use of Juvenile Hormone Analogues (JHA in sericulture practices has been shown to boost good cocoon yield; their effect has been determined to be dose-dependent. We studied the impact of low doses of JHA compounds such as methoprene and fenoxycarb on selected key enzymatic activities of the silkworm Bombyx mori. Methoprene and fenoxycarb at doses of 1.0 μg and 3.0fg/larvae/48 hours showed enhancement of the 5th instar B. mori larval muscle and silkgland protease, aspartate aminotransaminase (AAT and alanine aminotransaminase (ALAT, adenosine triphosphate synthase (ATPase and cytochrome-c-oxidase (CCO activity levels, indicating an upsurge in the overall oxidative metabolism of the B.mori larval tissues.

Characterization of Bombyx mori mitochondrial transcription factor A, a conserved regulator of mitochondrial DNA.

Science.gov (United States)

Sumitani, Megumi; Kondo, Mari; Kasashima, Katsumi; Endo, Hitoshi; Nakamura, Kaoru; Misawa, Toshihiko; Tanaka, Hiromitsu; Sezutsu, Hideki

2017-04-15

In the present study, we initially cloned and characterized a mitochondrial transcription factor A (Tfam) homologue in the silkworm, Bombyx mori. Bombyx mori TFAM (BmTFAM) localized to mitochondria in cultured silkworm and human cells, and co-localized with mtDNA nucleoids in human HeLa cells. In an immunoprecipitation analysis, BmTFAM was found to associate with human mtDNA in mitochondria, indicating its feature as a non-specific DNA-binding protein. In spite of the low identity between BmTFAM and human TFAM (26.5%), the expression of BmTFAM rescued mtDNA copy number reductions and enlarged mtDNA nucleoids in HeLa cells, which were induced by human Tfam knockdown. Thus, BmTFAM compensates for the function of human TFAM in HeLa cells, demonstrating that the mitochondrial function of TFAM is highly conserved between silkworms and humans. BmTfam mRNA was strongly expressed in early embryos. Through double-stranded RNA (dsRNA)-based RNA interference (RNAi) in silkworm embryos, we found that the knockdown of BmTFAM reduced the amount of mtDNA and induced growth retardation at the larval stage. Collectively, these results demonstrate that BmTFAM is a highly conserved mtDNA regulator and may be a good candidate for investigating and modulating mtDNA metabolism in this model organism. Copyright © 2017 Elsevier B.V. All rights reserved.

Characterization of the Bm61 of the Bombyx mori nucleopolyhedrovirus.

Science.gov (United States)

Shen, Hongxing; Chen, Keping; Yao, Qin; Zhou, Yang

2009-07-01

orf61 (bm61) of Bombyx mori Nucleopolyhedrovirus (BmNPV) is a highly conserved baculovirus gene, suggesting that it performs an important role in the virus life cycle whose function is unknown. In this study, we describe the characterization of bm61. Quantitative polymerase chain reaction (qPCR) and western blot analysis demonstrated that bm61 was expressed as a late gene. Immunofluorescence analysis by confocal microscopy showed that BM61 protein was localized on nuclear membrane and in intranuclear ring zone of infected cells. Structure localization of the BM61 in BV and ODV by western analysis demonstrated that BM61 was the protein of both BV and ODV. In addition, our data indicated that BM61 was a late structure protein localized in nucleus.

The influence of low level γ-radiation on the development of bombyx Mori L

International Nuclear Information System (INIS)

Yusifov, N.I.; Kuzin, A.M.; Agaev, F.A.; Mozgovoj, E.G.; AN Azerbajdzhanskoj SSR, Baku. Sektor Radiatsionnykh Issledovanij)

1988-01-01

Chronic γ-irradiation of a grain at a dose-rate 100, 1000 and 4000 times as high as that of the natural radiation background significantly accelerates the development of Bombyx moti L. The caterpillar development may also be stimulated by a single exposure of the grain to 2 Gy radiation. The acceleration of the caterpillar growth promotes the increase in the cocoon weight and the raw-silk mass

The influence of specific binding of collagen-silk chimeras to silk biomaterials on hMSC behavior.

Science.gov (United States)

An, Bo; DesRochers, Teresa M; Qin, Guokui; Xia, Xiaoxia; Thiagarajan, Geetha; Brodsky, Barbara; Kaplan, David L

2013-01-01

Collagen-like proteins in the bacteria Streptococcus pyogenes adopt a triple-helix structure with a thermal stability similar to that of animal collagens, can be expressed in high yield in Escherichia coli and can be easily modified through molecular biology techniques. However, potential applications for such recombinant collagens are limited by their lack of higher order structure to achieve the physical properties needed for most biomaterials. To overcome this problem, the S. pyogenes collagen domain was fused to a repetitive Bombyx mori silk consensus sequence, as a strategy to direct specific non-covalent binding onto solid silk materials whose superior stability, mechanical and material properties have been previously established. This approach resulted in the successful binding of these new collagen-silk chimeric proteins to silk films and porous scaffolds, and the binding affinity could be controlled by varying the number of repeats in the silk sequence. To explore the potential of collagen-silk chimera for regulating biological activity, integrin (Int) and fibronectin (Fn) binding sequences from mammalian collagens were introduced into the bacterial collagen domain. The attachment of bioactive collagen-silk chimeras to solid silk biomaterials promoted hMSC spreading and proliferation substantially in comparison to the controls. The ability to combine the biomaterial features of silk with the biological activities of collagen allowed more rapid cell interactions with silk-based biomaterials, improved regulation of stem cell growth and differentiation, as well as the formation of artificial extracellular matrices useful for tissue engineering applications. Copyright © 2012 Elsevier Ltd. All rights reserved.

Fabrication and characterization of biomaterial film from gland silk of muga and eri silkworms.

Science.gov (United States)

Dutta, Saranga; Talukdar, Bijit; Bharali, Rupjyoti; Rajkhowa, Rangam; Devi, Dipali

2013-05-01

This study discusses the possibilities of liquid silk (Silk gland silk) of Muga and Eri silk, the indigenous non mulberry silkworms of North Eastern region of India, as potential biomaterials. Silk protein fibroin of Bombyx mori, commonly known as mulberry silkworm, has been extensively studied as a versatile biomaterial. As properties of different silk-based biomaterials vary significantly, it is important to characterize the non mulberry silkworms also in this aspect. Fibroin was extracted from the posterior silk gland of full grown fifth instars larvae, and 2D film was fabricated using standard methods. The films were characterized using SEM, Dynamic contact angle test, FTIR, XRD, DSC, and TGA and compared with respective silk fibers. SEM images of films reveal presence of some globules and filamentous structure. Films of both the silkworms were found to be amorphous with random coil conformation, hydrophobic in nature, and resistant to organic solvents. Non mulberry silk films had higher thermal resistance than mulberry silk. Fibers were thermally more stable than the films. This study provides insight into the new arena of research in application of liquid silk of non mulberry silkworms as biomaterials. Copyright © 2012 Wiley Periodicals, Inc.

Development of an enzyme-linked-immunosorbent-assay technique for accurate identification of poorly preserved silks unearthed in ancient tombs.

Science.gov (United States)

Zheng, Qin; Wu, Xiaofeng; Zheng, Hailing; Zhou, Yang

2015-05-01

We report the preparation of a specific fibroin antibody and its use for the identification of unearthed ancient silk relics. Based on the 12-amino-acid repeat sequence "GAGAGSGAGAGS", which is found in fibroin of the silkworm Bombyx mori, a specific antibody against fibroin was prepared in rabbits through peptide synthesis and carrier-protein coupling. This antibody was highly specific for fibroin found in silk. Using this antibody we have successfully identified four silk samples from different time periods. Our results reveal, for the first time, a method capable of detecting silk from a few milligrams of archaeological fabric that has been buried for thousands of years, confirming that the ancient practice of wearing silk products while praying for rebirth dated back to at least 400 BCE. This method also complements current approaches in silk detection, especially for the characterization of poorly preserved silks, promoting the investigation of silk origins and of ancient clothing cultures.

Pheromone discrimination by a pH-tuned polymorphism of the Bombyx mori pheromone-binding protein

OpenAIRE

Damberger, Fred F.; Michel, Erich; Ishida, Yuko; Leal, Walter S.; Wüthrich, Kurt

2013-01-01

Pheromone recognition by insect olfactory organs is critical for the ability of insects to locate mates. The silkworm moth Bombyx mori has long served as a model organism for studies of this process. Key components in the sensory organs have been identified, including the pheromone bombykol, pheromone-binding protein (BmorPBP), ligand-degrading enzymes, and the pheromone receptor, but many details of the mechanism allowing highly sensitive and selective pheromone detection are still elusive. ...

Cloning and characterization of carboxyl terminus of heat shock cognate 70-interacting protein gene from the silkworm, Bombyx mori.

Science.gov (United States)

Ohsawa, Takeshi; Fujimoto, Shota; Tsunakawa, Akane; Shibano, Yuka; Kawasaki, Hideki; Iwanaga, Masashi

2016-11-01

Carboxyl terminus of heat shock cognate 70-interacting protein (CHIP) is an evolutionarily conserved E3 ubiquitin ligase across different eukaryotic species and is known to play a key role in protein quality control. CHIP has two distinct functional domains, an N-terminal tetratricopeptide repeat (TPR) and a C-terminal U-box domain, which are required for the ubiquitination of numerous labile client proteins that are chaperoned by heat shock proteins (HSPs) and heat shock cognate proteins (HSCs). During our screen for CHIP-like proteins in the Bombyx mori databases, we found a novel silkworm gene, Bombyx mori CHIP. Phylogenetic analysis showed that BmCHIP belongs to Lepidopteran lineages. Quantitative reverse transcription-PCR analysis indicated that BmCHIP was relatively highly expressed in the gonad and fat body. A pull-down experiment and auto-ubiquitination assay showed that BmCHIP interacted with BmHSC70 and had E3 ligase activity. Additionally, immunohistochemical analysis revealed that BmCHIP was partially co-localized with ubiquitin in BmN4 cells. These data support that BmCHIP plays an important role in the ubiquitin proteasome system as an E3 ubiquitin ligase in B. mori. Copyright © 2016 Elsevier Inc. All rights reserved.

Molecular cloning and characterization of the α-glucosidase II from Bombyx mori and Spodoptera frugiperda.

Science.gov (United States)

Watanabe, Satoko; Kakudo, Akemi; Ohta, Masato; Mita, Kazuei; Fujiyama, Kazuhito; Inumaru, Shigeki

2013-04-01

The α-glucosidase II (GII) is a heterodimer of α- and β-subunits and important for N-glycosylation processing and quality control of nascent glycoproteins. Although high concentration of α-glucosidase inhibitors from mulberry leaves accumulate in silkworms (Bombyx mori) by feeding, silkworm does not show any toxic symptom against these inhibitors and N-glycosylation of recombinant proteins is not affected. We, therefore, hypothesized that silkworm GII is not sensitive to the α-glucosidase inhibitors from mulberry leaves. However, the genes for B. mori GII subunits have not yet been identified, and the protein has not been characterized. Therefore, we isolated the B. mori GII α- and β-subunit genes and the GII α-subunit gene of Spodoptera frugiperda, which does not feed on mulberry leaves. We used a baculovirus expression system to produce the recombinant GII subunits and identified their enzyme characteristics. The recombinant GII α-subunits of B. mori and S. frugiperda hydrolyzed p-nitrophenyl α-d-glucopyranoside (pNP-αGlc) but were inactive toward N-glycan. Although the B. mori GII β-subunit was not required for the hydrolysis of pNP-αGlc, a B. mori GII complex of the α- and β-subunits was required for N-glycan cleavage. As hypothesized, the B. mori GII α-subunit protein was less sensitive to α-glucosidase inhibitors than was the S. frugiperda GII α-subunit protein. Our observations suggest that the low sensitivity of GII contributes to the ability of B. mori to evade the toxic effect of α-glucosidase inhibitors from mulberry leaves. Copyright © 2013 Elsevier Ltd. All rights reserved.

Influence of electron irradiation on the structural and thermal properties of silk fibroin films

Energy Technology Data Exchange (ETDEWEB)

Asha, S.; Sangappa,; Sanjeev, Ganesh, E-mail: ganeshanjeev@rediffmail.com [Department of Studies in Physics, Mangalore University, Mangalagangotri, Mangalore - 574 199 (India)

2015-06-24

Radiation-induced changes in Bombyx mori silk fibroin (SF) films under electron irradiation were investigated and correlated with dose. SF films were irradiated in air at room temperature using 8 MeV electron beam in the range 0-150 kGy. Various properties of the irradiated SF films were studied using X-ray diffraction (XRD), Differential Scanning Calorimetry (DSC) and Thermogravimetric Analysis (TGA). Electron irradiation was found to induce changes in the physical and thermal properties, depending on the radiation dose.

BmRobo2/3 is required for axon guidance in the silkworm Bombyx mori.

Science.gov (United States)

Li, Xiao-Tong; Yu, Qi; Zhou, Qi-Sheng; Zhao, Xiao; Liu, Zhao-Yang; Cui, Wei-Zheng; Liu, Qing-Xin

2016-02-15

Axon guidance is critical for proper wiring of the nervous system. During the neural development, the axon guidance molecules play a key role and direct axons to choose the correct way to reach the target. Robo, as the receptor of axon guidance molecule Slit, is evolutionarily conserved from planarians to humans. However, the function of Robo in the silkworm, Bombyx mori, remained unknown. In this study, we cloned robo2/3 from B. mori (Bmrobo2/3), a homologue of robo2/3 in Tribolium castaneum. Moreover, BmRobo2/3 was localized in the neuropil, and RNAi-mediated knockdown of Bmrobo2/3 resulted in the longitudinal connectives forming closer to the midline. These data demonstrate that BmRobo2/3 is required for axon guidance in the silkworm. Copyright © 2015 Elsevier B.V. All rights reserved.

Transcriptome analysis of the brain of the silkworm Bombyx mori infected with Bombyx mori nucleopolyhedrovirus: A new insight into the molecular mechanism of enhanced locomotor activity induced by viral infection.

Science.gov (United States)

Wang, Guobao; Zhang, Jianjia; Shen, Yunwang; Zheng, Qin; Feng, Min; Xiang, Xingwei; Wu, Xiaofeng

2015-06-01

Baculoviruses have been known to induce hyperactive behavior in their lepidopteran hosts for over a century. As a typical lepidopteran insect, the silkworm Bombyx mori displays enhanced locomotor activity (ELA) following infection with B. mori nucleopolyhedrovirus (BmNPV). Some investigations have focused on the molecular mechanisms underlying this abnormal hyperactive wandering behavior due to the virus; however, there are currently no reports about B. mori. Based on previous studies that have revealed that behavior is controlled by the central nervous system, the transcriptome profiles of the brains of BmNPV-infected and non-infected silkworm larvae were analyzed with the RNA-Seq technique to reveal the changes in the BmNPV-infected brain on the transcriptional level and to provide new clues regarding the molecular mechanisms that underlies BmNPV-induced ELA. Compared with the controls, a total of 742 differentially expressed genes (DEGs), including 218 up-regulated and 524 down-regulated candidates, were identified, of which 499, 117 and 144 DEGs could be classified into GO categories, KEGG pathways and COG annotations by GO, KEGG and COG analyses, respectively. We focused our attention on the DEGs that are involved in circadian rhythms, synaptic transmission and the serotonin receptor signaling pathway of B. mori. Our analyses suggested that these genes were related to the locomotor activity of B. mori via their essential roles in the regulations of a variety of behaviors and the down-regulation of their expressions following BmNPV infection. These results provide new insight into the molecular mechanisms of BmNPV-induced ELA. Copyright © 2015 Elsevier Inc. All rights reserved.

Feeding Single-Walled Carbon Nanotubes or Graphene to Silkworms for Reinforced Silk Fibers.

Science.gov (United States)

Wang, Qi; Wang, Chunya; Zhang, Mingchao; Jian, Muqiang; Zhang, Yingying

2016-10-12

Silkworm silk is gaining significant attention from both the textile industry and research society because of its outstanding mechanical properties and lustrous appearance. The possibility of creating tougher silks attracts particular research interest. Carbon nanotubes and graphene are widely studied for their use as reinforcement. In this work, we report mechanically enhanced silk directly collected by feeding Bombyx mori larval silkworms with single-walled carbon nanotubes (SWNTs) and graphene. We found that parts of the fed carbon nanomaterials were incorporated into the as-spun silk fibers, whereas the others went into the excrement of silkworms. Spectroscopy study indicated that nanocarbon additions hindered the conformation transition of silk fibroin from random coil and α-helix to β-sheet, which may contribute to increased elongation at break and toughness modules. We further investigated the pyrolysis of modified silk, and a highly developed graphitic structure with obviously enhanced electrical conductivity was obtained through the introduction of SWNTs and graphene. The successful generation of these SWNT- or graphene-embedded silks by in vivo feeding is expected to open up possibilities for the large-scale production of high-strength silk fibers.

MicroRNA-281 regulates the expression of ecdysone receptor (EcR) isoform B in the silkworm, Bombyx mori

Science.gov (United States)

Hundreds of Bombyx mori miRNAs had been identified in recent years, but their function in vivo remains poorly understood. The silkworm EcR gene (BmEcR) has three transcriptional isoforms, A, B1 and B2. Isoform sequences are different in the 3’UTR region of the gene, which is the case only in insects...

Crystal structure of Bombyx mori arylphorins reveals a 3:3 heterohexamer with multiple papain cleavage sites

Science.gov (United States)

Hou, Yong; Li, Jianwei; Li, Yi; Dong, Zhaoming; Xia, Qingyou; Yuan, Y Adam

2014-01-01

In holometabolous insects, the accumulation and utilization of storage proteins (SPs), including arylphorins and methionine-rich proteins, are critical for the insect metamorphosis. SPs function as amino acids reserves, which are synthesized in fat body, secreted into the larval hemolymph and taken up by fat body shortly before pupation. However, the detailed molecular mechanisms of digestion and utilization of SPs during development are largely unknown. Here, we report the crystal structure of Bombyx mori arylphorins at 2.8 Å, which displays a heterohexameric structural arrangement formed by trimerization of dimers comprising two structural similar arylphorins. Our limited proteolysis assay and microarray data strongly suggest that papain-like proteases are the major players for B. mori arylphorins digestion in vitro and in vivo. Consistent with the biochemical data, dozens of papain cleavage sites are mapped on the surface of the heterohexameric structure of B. mori arylphorins. Hence, our results provide the insightful information to understand the metamorphosis of holometabolous insects at molecular level. PMID:24639361

New insights into the catalytic mechanism of Bombyx mori prostaglandin E synthase gained from structure–function analysis

Energy Technology Data Exchange (ETDEWEB)

Yamamoto, Kohji, E-mail: yamamok@agr.kyushu-u.ac.jp [Faculty of Agriculture, Kyushu University Graduate School, 6-10-1 Hakozaki, Higashi-ku, Fukuoka 812-8581 (Japan); Suzuki, Mamoru; Higashiura, Akifumi [Institute for Protein Research, Osaka University, Suita 565-0871 (Japan); Aritake, Kosuke; Urade, Yoshihiro; Uodome, Nobuko [Department of Molecular Behavioral Biology, Osaka Bioscience Institute, 6-2-4 Furuedai, Suita, Osaka 565-0874 (Japan); Hossain, MD. Tofazzal [Faculty of Agriculture, Kyushu University Graduate School, 6-10-1 Hakozaki, Higashi-ku, Fukuoka 812-8581 (Japan); Nakagawa, Atsushi [Institute for Protein Research, Osaka University, Suita 565-0871 (Japan)

2013-11-01

Highlights: •Structure of Bombyx mori prostaglandin E synthase is determined. •Bound glutathione sulfonic acid is located at the glutathione-binding site. •Electron-sharing network is present in this protein. •This network includes Asn95, Asp96, and Arg98. •Site-directed mutagenesis reveals that the residues contribute to the catalytic activity. -- Abstract: Prostaglandin E synthase (PGES) catalyzes the isomerization of PGH{sub 2} to PGE{sub 2}. We previously reported the identification and structural characterization of Bombyx mori PGES (bmPGES), which belongs to Sigma-class glutathione transferase. Here, we extend these studies by determining the structure of bmPGES in complex with glutathione sulfonic acid (GTS) at a resolution of 1.37 Å using X-ray crystallography. GTS localized to the glutathione-binding site. We found that electron-sharing network of bmPGES includes Asn95, Asp96, and Arg98. Site-directed mutagenesis of these residues to create mutant forms of bmPGES mutants indicate that they contribute to catalytic activity. These results are, to our knowledge, the first to reveal the presence of an electron-sharing network in bmPGES.

Structural evolution of regenerated silk fibroin under shear: Combined wide- and small-angle x-ray scattering experiments using synchrotron radiation

International Nuclear Information System (INIS)

Rossle, Manfred; Panine, Pierre; Urban, Volker S.; Riekel, Christine

2004-01-01

The structural evolution of regenerated Bombyx mori silk fibroin during shearing with a Couette cell has been studied in situ by synchrotron radiation small- and wide-angle x-ray scattering techniques. An elongation of fibroin molecules was observed with increasing shear rate, followed by an aggregation phase. The aggregates were found to be amorphous with β-conformation according to infrared spectroscopy. Scanning x-ray microdiffraction with a 5 (micro)m beam on aggregated material, which had solidified in air, showed silk II reflections and a material with equatorial reflections close to the silk I structure reflections, but with strong differences in reflection intensities. This silk I type material shows up to two low-angle peaks suggesting the presence of water molecules that might be intercalated between hydrogen-bonded sheets.

Structural evolution of regenerated silk fibroin under shear: Combined wide- and small-angle x-ray scattering experiments using synchrotron radiation

Energy Technology Data Exchange (ETDEWEB)

Rossle, Manfred [European Molecular Biology Laboratory (EMBL), France; Panine, Pierre [European Synchrotron Radiation Facility (ESRF); Urban, Volker S [ORNL; Riekel, Christine [European Synchrotron Radiation Facility (ESRF)

2004-04-01

The structural evolution of regenerated Bombyx mori silk fibroin during shearing with a Couette cell has been studied in situ by synchrotron radiation small- and wide-angle x-ray scattering techniques. An elongation of fibroin molecules was observed with increasing shear rate, followed by an aggregation phase. The aggregates were found to be amorphous with {beta}-conformation according to infrared spectroscopy. Scanning x-ray microdiffraction with a 5 {micro}m beam on aggregated material, which had solidified in air, showed silk II reflections and a material with equatorial reflections close to the silk I structure reflections, but with strong differences in reflection intensities. This silk I type material shows up to two low-angle peaks suggesting the presence of water molecules that might be intercalated between hydrogen-bonded sheets.

Electricity from the Silk Cocoon Membrane

Science.gov (United States)

Tulachan, Brindan; Meena, Sunil Kumar; Rai, Ratan Kumar; Mallick, Chandrakant; Kusurkar, Tejas Sanjeev; Teotia, Arun Kumar; Sethy, Niroj Kumar; Bhargava, Kalpana; Bhattacharya, Shantanu; Kumar, Ashok; Sharma, Raj Kishore; Sinha, Neeraj; Singh, Sushil Kumar; Das, Mainak

2014-01-01

Silk cocoon membrane (SCM) is an insect engineered structure. We studied the electrical properties of mulberry (Bombyx mori) and non-mulberry (Tussar, Antheraea mylitta) SCM. When dry, SCM behaves like an insulator. On absorbing moisture, it generates electrical current, which is modulated by temperature. The current flowing across the SCM is possibly ionic and protonic in nature. We exploited the electrical properties of SCM to develop simple energy harvesting devices, which could operate low power electronic systems. Based on our findings, we propose that the temperature and humidity dependent electrical properties of the SCM could find applications in battery technology, bio-sensor, humidity sensor, steam engines and waste heat management. PMID:24961354

New synthesis of a stereoisomeric mixture of methyl 12-trishomofarnesoate, a juvenile hormone mimic useful in sericulture by increasing silk production.

Science.gov (United States)

Mori, Kenji

2017-01-01

A mixture of (E,Z)-isomers of methyl 12-trishomofarnesoate (methyl 3,7,11-trimethyl-2,6,10-pentadecatrienoate), a juvenile hormone mimic, was synthesized in nine steps (32.6% overall yield) by starting from only four commercially available materials: 2-hexanone, vinylmagnesium bromide, methyl acetoacetate and trimethyl phosphonoacetate. The mimic is useful in increasing the yield of silk by elongating the larval period of the silkworm, Bombyx mori (L.).

Reproductive performance of Palmistichus elaeisis Delvare and LaSalle (Hymenoptera: Eulophidae) with previously refrigerated pupae of Bombyx mori L. (Lepidoptera: Bombycidae)

OpenAIRE

Pereira, FF.; Zanuncio, JC.; Serrão, JE.; Pastori, PL.; Ramalho, F.S.

2009-01-01

The mass rearing of parasitoids represents a fundamental stage for programmes of biological control. The progeny of the parasitoid Palmistichus elaeisis Delvare and LaSalle (Hymenoptera: Eulophidae) were evaluated on previously refrigerated pupae of Bombyx mori L. (Lepidoptera: Bombycidae). Forty-eight to 72 hours-old pupae of B. mori were stored at 10 ºC for five, 10, 15 or 20 days and then exposed to parasitism by P. elaeisis females. This parasitoid showed shorter duration of the life cycl...

Identification and characterization of vp7 gene in Bombyx mori cytoplasmic polyhedrosis virus.

Science.gov (United States)

He, Lei; Hu, Xiaolong; Zhu, Min; Liang, Zi; Chen, Fei; Zhu, Liyuan; Kuang, Sulan; Cao, Guangli; Xue, Renyu; Gong, Chengliang

2017-09-05

The genome of Bombyx mori cytoplasmic polyhedrosis virus (BmCPV) contains 10 double stranded RNA segments (S1-S10). The segment 7 (S7) encodes 50kDa protein which is considered as a structural protein. The expression pattern and function of p50 in the virus life cycle are still unclear. In this study, the viral structural protein 7 (VP7) polyclonal antibody was prepared with immunized mouse to explore the presence of small VP7 gene-encoded proteins in Bombyx mori cytoplasmic polyhedrosis virus. The expression pattern of vp7 gene was investigated by its overexpression in BmN cells. In addition to VP7, supplementary band was identified with western blotting technique. The virion, BmCPV infected cells and midguts were also examined using western blotting technique. 4, 2 and 5 bands were detected in the corresponding samples, respectively. The replication of BmCPV genome in the cultured cells and midgut of silkworm was decreased by reducing the expression level of vp7 gene using RNA interference. In immunoprecipitation experiments, using a polyclonal antiserum directed against the VP7, one additional shorter band in BmCPV infected midguts was detected, and then the band was analyzed with mass spectrum (MS), the MS results showed thatone candidate interacted protein (VP7 voltage-dependent anion-selective channel-like isoform, VDAC) was identified from silkworm. We concluded that the novel viral product was generated with a leaky scanning mechanism and the VDAC may be an interacted protein with VP7. Copyright © 2017 Elsevier B.V. All rights reserved.

Inter- and intra-population genetic variability of introduced silkworm (Bombyx mori L.) strains raised in Bulgaria

OpenAIRE

Teodora Staykova

2013-01-01

The genetic variability of four populations belonging to two introduced silkworm strains (Bombyx mori L.) of various origins has been studied using isoenzymic analysis of six enzyme systems. Nonspecific esterases, phosphoglucomutase, malate dehydrogenase, acid phosphatase, alkaline phosphatase and hexokinase from different tissue of larvae 5th instar have been analysed using PAGE. Polymorphism in six from a total of nine loci has been found. Inter- and intra-population differences have been a...

Vitellogenin from the silkworm, Bombyx mori: an effective anti-bacterial agent.

Science.gov (United States)

Singh, Nitin Kumar; Pakkianathan, Britto Cathrin; Kumar, Manish; Prasad, Tulika; Kannan, Mani; König, Simone; Krishnan, Muthukalingan

2013-01-01

Silkworm, Bombyx mori, vitellogenin (Vg) was isolated from perivisceral fat body of day 3 of pupa. Both Vg subunits were co-purified as verified by mass spectrometry and immunoblot. Purified Vg responded to specific tests for major posttranslational modifications on native gels indicating its nature as lipo-glyco-phosphoprotein. The Vg fraction had strong antibacterial activity against Gram negative bacterium Escherichia coli and Gram positive bacterium Bacillus subtilis. Microscopic images showed binding of Vg to bacterial cells and their destruction. When infected silkworm larvae were treated with purified Vg they survived the full life cycle in contrast to untreated animals. This result showed that Vg has the ability to inhibit the proliferation of bacteria in the silkworm fluid system without disturbing the regular metabolism of the host.

Characterization of Bombyx mori nucleopolyhedrovirus with a knockout of Bm17.

Science.gov (United States)

Shen, Hongxing; Zhou, Yang; Zhang, Wen; Nin, Bin; Wang, Hua; Wang, Xiaochun; Shao, Shihe; Chen, Huiqing; Guo, Zhongjian; Liu, Xiaoyong; Yao, Qin; Chen, Keping

2012-12-01

Open reading frame 17 (Bm17) gene of Bombyx mori nucleopolyhedrovirus is a highly conserved gene in lepidopteran nucleopolyhedroviruses, but its function remains unknown. In this report, transient-expression and superinfection assays indicated that BM17 localized in the nucleus and cytoplasm of infected BmN cells. To determine the role of Bm17 in baculovirus life cycle, we constructed a Bm17 knockout virus and characterized its properties in cells. Analysis of the production and infection of budded virions, the level of viral DNA replication revealed showed that there was no significant difference among the mutant, the control, and the Bm17 repaired virus strains. These results suggest that BM17 is not essential for virus replication in cultured cells.

Effect of solvents on properties of Bombyx mori silk grafted by methyl methacrylate (MMA and methacrylamide (MAA

Directory of Open Access Journals (Sweden)

Wattana Klairatsamee

2005-11-01

Full Text Available Mulberry silks were chemically modified in order to increase weight gain, resulting from degumming process using graft copolymerisation technique with vinyl monomers, i.e. MMA, MAA and MMA/MAA. Due to the appearance of PMMA homopolymer granules adhered on the MMA- and MMA/MAA-grafted silk surfaces resulting in surface roughness when silk was grafted by MMA in water, the influence of grafting solvents was examined, using different water/ethanol volume ratios of 100/0, 75/25, 50/50, 25/75 and 0/100. FTIR spectra of the grafted silks presented the absorption bands of the vinyl monomers used for the grafting process. In addition, high values of % polymer add-on were obtained for all of the grafted silks. It was also found that the suitable solvents were 25/75 water/ethanol for the silk grafted by MMA and MMA/MAA, and water for the silk grafted by MAA, in order to get the smooth grafted silk surface and high polymer add-on. Moreover, all the grafted silks showed slightly greater stiffness, as indicated by the increase of Young's modulus and the decrease of elongation.

An optically transparent, flexible, patterned and conductive silk biopolymer film (Conference Presentation)

Science.gov (United States)

Umar, Muhammad; Min, Kyungtaek; Kim, Sunghwan

2017-02-01

Transparent, flexible, and conducting films are of great interest for wearable electronics. For better biotic/abiotic interface, the films to integrate the electronics components requires the patterned surface conductors with optical transparency, smoothness, good electrical conductivity, along with the biofriendly traits of films. We focus on silk fibroin, a natural biopolymer extracted from the Bombyx mori cocoons, for this bioelectronics applications. Here we report an optically transparent, flexible, and patterned surface conductor on a silk film by burying a silver nanowires (AgNW) network below the surface of the silk film. The conducting silk film reveals high optical transparency of 80% and the excellent electronic conductivity of 15 Ω/sq, along with smooth surface. The integration of light emitting diode (LED) chip on the patterned electrodes confirms that the current can flow through the transparent and patterned electrodes on the silk film, and this result shows an application for integration of functional electronic/opto-electronic devices. Additionally, we fabricate a transparent and flexible radio frequency (RF) antenna and resistor on a silk film and apply these as a food sensor by monitoring the increasing resistance by the flow of gases from the spoiled food.

Molecular characterization of DnaJ 5 homologs in silkworm Bombyx mori and its expression during egg diapause.

Science.gov (United States)

Sirigineedi, Sasibhushan; Vijayagowri, Esvaran; Murthy, Geetha N; Rao, Guruprasada; Ponnuvel, Kangayam M

2014-12-01

A comparison of the cDNA sequences (1 056 bp) of Bombyx mori DnaJ 5 homolog with B. mori genome revealed that unlike in other Hsps, it has an intron of 234 bp. The DnaJ 5 homolog contains 351 amino acids, of which 70 contain the conserved DnaJ domain at the N-terminal end. This homolog of B. mori has all desirable functional domains similar to other insects, and the 13 different DnaJ homologs identified in B. mori genome were distributed on different chromosomes. The expressed sequence tag database analysis of Hsp40 gene expression revealed higher expression in wing disc followed by diapause-induced eggs. Microarray analysis revealed higher expression of DnaJ 5 homolog at 18th h after oviposition in diapause-induced eggs. Further validation of DnaJ 5 expression through qPCR in diapause-induced and nondiapause eggs at different time intervals revealed higher expression in diapause eggs at 18 and 24 h after oviposition, which coincided with the expression of Hsp70 as the Hsp 40 is its co-chaperone. This study thus provides an outline of the genome organization of Hsp40 gene, and its role in egg diapause induction in B. mori. © 2013 Institute of Zoology, Chinese Academy of Sciences.

Development and reproduction of Podisus distinctus (Heteroptera: Pentatomidae) fed on larva of Bombyx mori (Lepidoptera: Bombycidae)

OpenAIRE

Lacerda, M. C.; Ferreira, A. M. R. M.; Zanuncio, T. V.; Zanuncio, J. C.; Bernardino, A. S.; Espindula, M. C.

2004-01-01

Biological control has been reducing the use of chemical products against insect pests, specially predatory Pentatomidae. Species of this group can present high variations in their life cycle as a result of their diet. Thus, the objective of this research was to study nymph development and reproduction of Podisus distinctus (Stäl, 1860) (Heteroptera: Pentatomidae) fed on Bombyx mori L., 1758 (Lepidoptera: Bombycidae) larvae (T1), compared to those fed on Tenebrio molitor L., 1758 (Coleoptera:...

The Bombyx mori nucleopolyhedrovirus Bm111 affects virulence but not virus replication.

Science.gov (United States)

Han, Yingying; Xia, Hengchuan; Tang, Qi; Lü, Peng; Ma, Shangshang; Yang, Yanhua; Shao, Dandan; Ma, Quanbing; Chen, Keping

2014-07-01

The Bm111 of Bombyx mori nucleopolyhedrovirus (BmNPV) encodes a small polypeptide (70 amino acids) of which the function remains unknown. To characterize its function, multiple sequence alignments were performed, and the predicted protein was found to share amazingly high (98 %) sequence identity with the Bombyx mandarina nucleopolyhedrovirus ORF110 (Boma110) but negligible with proteins of other insect viruses, indicating the close relationship between these two NPVs with silkworm larvae. The transcription of Bm111 was detected as early as 3 hpi in BmNPV-infected BmN cells, suggesting it is an early gene. To investigate the role of Bm111 in baculovirus life cycle, a Bm111-knockout virus was constructed by bacmid recombination in Escherichia coli. The results showed that knockout of the Bm111 did not affect the replication of virus DNA, but significantly extended the death time of infected silkworm larvae compared to the wild-type or rescued viruses. We also successfully expressed the recombinant protein Bm111 in E. coli to provide sufficient material for subsequent studies. Taken together, our data indicate that Bm111 only affects the virulence of BmNPV, but not its replication.

Reproductive performance of Palmistichus elaeisis Delvare and LaSalle (Hymenoptera: Eulophidae with previously refrigerated pupae of Bombyx mori L. (Lepidoptera: Bombycidae

Directory of Open Access Journals (Sweden)

FF. Pereira

Full Text Available The mass rearing of parasitoids represents a fundamental stage for programmes of biological control. The progeny of the parasitoid Palmistichus elaeisis Delvare and LaSalle (Hymenoptera: Eulophidae were evaluated on previously refrigerated pupae of Bombyx mori L. (Lepidoptera: Bombycidae. Forty-eight to 72 hours-old pupae of B. mori were stored at 10 ºC for five, 10, 15 or 20 days and then exposed to parasitism by P. elaeisis females. This parasitoid showed shorter duration of the life cycle when reared on pupae of B. mori which were previously stored at 10 ºC during 15 days. P. elaeisis parasitized 100% of the pupae of B. mori after storage at 10 ºC during all periods with emergence of this parasitoid from 78 to 100% of these pupae. P. elaeisis had a higher number of progeny per pupa of B. mori stored for 15 days at 10 ºC. Pupae of B. mori can be stored for 15 days at 10 ºC before being used to rear P. elaeisis.

Reproductive performance of Palmistichus elaeisis Delvare and LaSalle (Hymenoptera: Eulophidae) with previously refrigerated pupae of Bombyx mori L. (Lepidoptera: Bombycidae).

Science.gov (United States)

Pereira, F F; Zanuncio, J C; Serrão, J E; Pastori, P L; Ramalho, F S

2009-08-01

The mass rearing of parasitoids represents a fundamental stage for programmes of biological control. The progeny of the parasitoid Palmistichus elaeisis Delvare and LaSalle (Hymenoptera: Eulophidae) were evaluated on previously refrigerated pupae of Bombyx mori L. (Lepidoptera: Bombycidae). Forty-eight to 72 hours-old pupae of B. mori were stored at 10 degrees C for five, 10, 15 or 20 days and then exposed to parasitism by P. elaeisis females. This parasitoid showed shorter duration of the life cycle when reared on pupae of B. mori which were previously stored at 10 degrees C during 15 days. P. elaeisis parasitized 100% of the pupae of B. mori after storage at 10 degrees C during all periods with emergence of this parasitoid from 78 to 100% of these pupae. P. elaeisis had a higher number of progeny per pupa of B. mori stored for 15 days at 10 degrees C. Pupae of B. mori can be stored for 15 days at 10 degrees C before being used to rear P. elaeisis.

Bombyx mori nucleopolyhedrovirus BM5 protein regulates progeny virus production and viral gene expression

International Nuclear Information System (INIS)

Kokusho, Ryuhei; Koh, Yoshikazu; Fujimoto, Masaru; Shimada, Toru; Katsuma, Susumu

2016-01-01

Bombyx mori nucleopolyhedrovirus (BmNPV) orf5 (Bm5) is a core gene of lepidopteran baculoviruses and encodes the protein with the conserved amino acid residues (DUF3627) in its C-terminus. Here, we found that Bm5 disruption resulted in lower titers of budded viruses and fewer numbers of occlusion bodies (OBs) in B. mori cultured cells and larvae, although viral genome replication was not affected. Bm5 disruption also caused aberrant expression of various viral genes at the very late stage of infection. Immunocytochemical analysis revealed that BM5 localized to the nuclear membrane. We also found that DUF3627 is important for OB production, transcriptional regulation of viral genes, and subcellular localization of BM5. Compared with wild-type BmNPV infection, larval death was delayed when B. mori larvae were infected with Bm5 mutants. These results suggest that BM5 is involved in progeny virus production and regulation of viral gene expression at the very late stage of infection. -- Highlights: •The role of BmNPV BM5 protein was examined in B. mori cultured cells and larvae. •BM5 contributes to efficient production of budded viruses and occlusion bodies. •BM5 regulates viral gene expression at the very late stage of infection. •BM5 dominantly localizes to the nuclear membrane. •Bm5 mutant showed v-cath down-regulation and resulting delay of larval death.

Bombyx mori nucleopolyhedrovirus BM5 protein regulates progeny virus production and viral gene expression

Energy Technology Data Exchange (ETDEWEB)

Kokusho, Ryuhei, E-mail: kokusho@ss.ab.a.u-tokyo.ac.jp; Koh, Yoshikazu; Fujimoto, Masaru; Shimada, Toru; Katsuma, Susumu, E-mail: katsuma@ss.ab.a.u-tokyo.ac.jp

2016-11-15

Bombyx mori nucleopolyhedrovirus (BmNPV) orf5 (Bm5) is a core gene of lepidopteran baculoviruses and encodes the protein with the conserved amino acid residues (DUF3627) in its C-terminus. Here, we found that Bm5 disruption resulted in lower titers of budded viruses and fewer numbers of occlusion bodies (OBs) in B. mori cultured cells and larvae, although viral genome replication was not affected. Bm5 disruption also caused aberrant expression of various viral genes at the very late stage of infection. Immunocytochemical analysis revealed that BM5 localized to the nuclear membrane. We also found that DUF3627 is important for OB production, transcriptional regulation of viral genes, and subcellular localization of BM5. Compared with wild-type BmNPV infection, larval death was delayed when B. mori larvae were infected with Bm5 mutants. These results suggest that BM5 is involved in progeny virus production and regulation of viral gene expression at the very late stage of infection. -- Highlights: •The role of BmNPV BM5 protein was examined in B. mori cultured cells and larvae. •BM5 contributes to efficient production of budded viruses and occlusion bodies. •BM5 regulates viral gene expression at the very late stage of infection. •BM5 dominantly localizes to the nuclear membrane. •Bm5 mutant showed v-cath down-regulation and resulting delay of larval death.

Development and silk production by silkworm larvae after topical application of methoprene

Directory of Open Access Journals (Sweden)

Miranda José Ednilson

2002-01-01

Full Text Available Juvenile hormone analogues have been tested as insect growth regulators in silkworm (Bombyx mori, seeking an increment of silk production. These chemical products, when applied in small or moderate rates, promote the extension of the last larval instar. To understand the physiologic consequences on silk production by the silkworm strain C115 x N108, the application of methoprene, a juvenile hormone analogue, was performed to evaluate its effects on larval development and silk production. Methoprene was topically applied 48h after the fourth larval ecdysis, on the dorsal integument of the 2nd thoracic segment of the insects, at seven rates between 0 and 20 ng a.i. Methoprene influenced positively the duration of the fifth instar and the weight gain of the insects. The application of 1ng methoprene resulted in the heaviest silkglands, cocoons, shell cocoons and pupae weights. Comparatively to the control, the increment on silk production (approximately 24% by the use of 1ng methoprene was more accentuated than the corresponding negative effects on the cocooning rate (approximately 12%.

Control of protein synthesis in the female pupa of Bombyx mori

International Nuclear Information System (INIS)

Yamao, Masami; Koga, Katsumi

1975-01-01

For the purpose of understanding the mechanisms of insect metamorphosis, protein synthesis by silkmoth pupae has been studied. Synthetic rate and contents of total RNA and protein changed markedly in the female pupae of Bombyx mori. Attempt was made to find what the limiting step for the synthesis of the bulk of proteins during the adult development of female pupae is. Several female pupae of hydridstrain were homogenized at each of stated periods in buffer. The ribosomal fraction prepared from the homogenates was incubated in the buffer containing 3 H-leucine or 3 H-phenylalanine. The incorporation of leucine depending on endogenous mRNA and that of phenylalanine directed by added poly U were the largest in 9--10 days and 7th day, respectively. From the results, the synthesis of protein during the late adult development of female silkworms is controlled at the level of mRNA. The increase of ribosomes, which were active to bind mRNA, preceded the appearance of available endogenous mRNA, and it may be attributed to neogenesis and ''run-off'' of previous ribosomes. It is conceivable that such neogenesis or run-off serves as less direct control for the protein synthesis during the metamorphosis of Bombix mori. (Kobatake, H.)

Identification of specific sites in the third intracellular loop and carboxyl terminus of the Bombyx mori PBAN receptor crucial for ligand-induced internalization

Science.gov (United States)

Sex pheromone production in most moths is mediated by the pheromone biosynthesis activating neuropeptide receptor (PBANR). Similar to other rhodopsin-like G protein-coupled receptors, the silkmoth Bombyx mori PBANR (BmPBANR) undergoes agonist-induced internalization. Despite interest in developing...

A Single Sex Pheromone Receptor Determines Chemical Response Specificity of Sexual Behavior in the Silkmoth Bombyx mori

OpenAIRE

Sakurai, Takeshi; Mitsuno, Hidefumi; Haupt, Stephan Shuichi; Uchino, Keiro; Yokohari, Fumio; Nishioka, Takaaki; Kobayashi, Isao; Sezutsu, Hideki; Tamura, Toshiki; Kanzaki, Ryohei

2011-01-01

In insects and other animals, intraspecific communication between individuals of the opposite sex is mediated in part by chemical signals called sex pheromones. In most moth species, male moths rely heavily on species-specific sex pheromones emitted by female moths to identify and orient towards an appropriate mating partner among a large number of sympatric insect species. The silkmoth, Bombyx mori, utilizes the simplest possible pheromone system, in which a single pheromone component, (E, Z...

Vitellogenin from the silkworm, Bombyx mori: an effective anti-bacterial agent.

Directory of Open Access Journals (Sweden)

Nitin Kumar Singh

Full Text Available Silkworm, Bombyx mori, vitellogenin (Vg was isolated from perivisceral fat body of day 3 of pupa. Both Vg subunits were co-purified as verified by mass spectrometry and immunoblot. Purified Vg responded to specific tests for major posttranslational modifications on native gels indicating its nature as lipo-glyco-phosphoprotein. The Vg fraction had strong antibacterial activity against Gram negative bacterium Escherichia coli and Gram positive bacterium Bacillus subtilis. Microscopic images showed binding of Vg to bacterial cells and their destruction. When infected silkworm larvae were treated with purified Vg they survived the full life cycle in contrast to untreated animals. This result showed that Vg has the ability to inhibit the proliferation of bacteria in the silkworm fluid system without disturbing the regular metabolism of the host.

Soaking RNAi in Bombyx mori BmN4-SID1 Cells Arrests Cell Cycle Progression

Science.gov (United States)

Mon, Hiroaki; Li, Zhiqing; Kobayashi, Isao; Tomita, Shuichiro; Lee, JaeMan; Sezutsu, Hideki; Tamura, Toshiki; Kusakabe, Takahiro

2013-01-01

RNA interference (RNAi) is an evolutionarily conserved mechanism for sequence-specific gene silencing. Previously, the BmN4-SID1 cell expressing Caenorhabditis ele gans SID-1 was established, in which soaking RNAi could induce effective gene silencing. To establish its utility, 6 cell cycle progression related cDNAs, CDK1, MYC, MYB, RNRS, CDT1, and GEMININ, were isolated from the silkworm, Bombyx mori L. (Lepidoptera: Bombycidae), and their expressions were further silenced by soaking RNAi in the BmN4-SID1 cells. The cell cycle progression analysis using flow cytometer demonstrated that the small amount of double stranded RNA was enough to arrest cell cycle progression at the specific cell phases. These data suggest that RNAi in the BmN4-SID1 cells can be used as a powerful tool for loss-of-function analysis of B. mori genes. PMID:24773378

Transcriptome sequencing and positive selected genes analysis of Bombyx mandarina.

Directory of Open Access Journals (Sweden)

Tingcai Cheng

Full Text Available The wild silkworm Bombyx mandarina is widely believed to be an ancestor of the domesticated silkworm, Bombyx mori. Silkworms are often used as a model for studying the mechanism of species domestication. Here, we performed transcriptome sequencing of the wild silkworm using an Illumina HiSeq2000 platform. We produced 100,004,078 high-quality reads and assembled them into 50,773 contigs with an N50 length of 1764 bp and a mean length of 941.62 bp. A total of 33,759 unigenes were identified, with 12,805 annotated in the Nr database, 8273 in the Pfam database, and 9093 in the Swiss-Prot database. Expression profile analysis found significant differential expression of 1308 unigenes between the middle silk gland (MSG and posterior silk gland (PSG. Three sericin genes (sericin 1, sericin 2, and sericin 3 were expressed specifically in the MSG and three fibroin genes (fibroin-H, fibroin-L, and fibroin/P25 were expressed specifically in the PSG. In addition, 32,297 Single-nucleotide polymorphisms (SNPs and 361 insertion-deletions (INDELs were detected. Comparison with the domesticated silkworm p50/Dazao identified 5,295 orthologous genes, among which 400 might have experienced or to be experiencing positive selection by Ka/Ks analysis. These data and analyses presented here provide insights into silkworm domestication and an invaluable resource for wild silkworm genomics research.

The Expression, Purification, and Characterization of a Ras Oncogene (Bras2) in Silkworm (Bombyx mori)

OpenAIRE

Lv, Zhengbing; Wang, Tao; Zhuang, Wenhua; Wang, Dan; Chen, Jian; Nie, Zuoming; Liu, Lili; Zhang, Wenping; Wang, Lisha; Wang, Deming; Wu, Xiangfu; Li, Jun; Qian, Lian; Zhang, Yaozhou

2013-01-01

The Ras oncogene of silkworm pupae (Bras2) may belong to the Ras superfamily. It shares 77% of its amino acid identity with teratocarcinoma oncogene 21 (TC21) related ras viral oncogene homolog-2 (R-Ras2) and possesses an identical core effector region. The mRNA of Bombyx mori Bras2 has 1412 bp. The open reading frame contains 603 bp, which encodes 200 amino acid residues. This recombinant BmBras2 protein was subsequently used as an antigen to raise a rabbit polyclonal antibody. Western blott...

Identification of plasmalogen in the gut of silkworm (Bombyx mori).

Science.gov (United States)

Aboshi, Takako; Nishida, Ritsuo; Mori, Naoki

2012-08-01

Herbivorous insect species are constantly challenged with endogenous and exogenous oxidative stress. Consequently, they possess an array of antioxidant enzymes and small molecular weight antioxidants. Lipid-soluble small molecular antioxidants, such as tocopherols, have not been well studied in insects but may play important antioxidant roles. In this study, we identified plasmalogen phosphatidylethanolamines (pPEs) as well as α-, β/γ-, δ-tocopherol in the larvae of the silkworm Bombyx mori by LCMS analyses and examined their distribution. Plasmalogen are reported to inhibit the metal ion induced oxidation. The composition of tocopherols was the same among gut contents, gut tissues, and the other tissues. However, plasmalogens, a unique class of glycerophospholipids rich in polyunsaturated fatty acids and containing a vinyl ether bond at the sn-1 position, were mainly distributed in gut tissues. Plasmalogens might protect gut tissues from oxidation stress. Copyright © 2012 Elsevier Ltd. All rights reserved.

Radiation degradation of silk protein

Energy Technology Data Exchange (ETDEWEB)

Wachiraporn Pewlong; Boonya Sudatis [Office of Atomic Energy for Peace, Bangkok (Thailand); Takeshita, Hidefumi; Yoshii, Fumio; Kume, Tamikazu [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment

2000-09-01

Silk fibroin fiber from the domesticated silkworm Bombyx mori was irradiated in the dose range up to 2500 kGy using an electron beam accelerator to apply the radiation degradation technique as a means to solubilize fibroin. The tensile strength of irradiated fibroin fiber decreased with increasing dose and the presence of oxygen in the irradiation atmosphere enhanced the degradation. The solubilization of irradiated fibroin fiber was evaluated using the following three kinds of solutions: calcium chloride solution (CaCl{sub 2}/C{sub 2}H{sub 5}OH/H{sub 2}O = 1 : 2 : 8 in mole ratio), hydrochloric acid (0.5N) and distilled water. Dissolution of fibroin fiber into these solutions was significantly enhanced by irradiation. Especially, an appreciable amount of water-soluble protein was extracted by distilled water. (author)

Transgenic Expression of the piRNA-Resistant Masculinizer Gene Induces Female-Specific Lethality and Partial Female-to-Male Sex Reversal in the Silkworm, Bombyx mori.

Science.gov (United States)

Sakai, Hiroki; Sumitani, Megumi; Chikami, Yasuhiko; Yahata, Kensuke; Uchino, Keiro; Kiuchi, Takashi; Katsuma, Susumu; Aoki, Fugaku; Sezutsu, Hideki; Suzuki, Masataka G

2016-08-01

In Bombyx mori (B. mori), Fem piRNA originates from the W chromosome and is responsible for femaleness. The Fem piRNA-PIWI complex targets and cleaves mRNAs transcribed from the Masc gene. Masc encodes a novel CCCH type zinc-finger protein and is required for male-specific splicing of B. mori doublesex (Bmdsx) transcripts. In the present study, several silkworm strains carrying a transgene, which encodes a Fem piRNA-resistant Masc mRNA (Masc-R), were generated. Forced expression of the Masc-R transgene caused female-specific lethality during the larval stages. One of the Masc-R strains weakly expressed Masc-R in various tissues. Females heterozygous for the transgene expressed male-specific isoform of the Bombyx homolog of insulin-like growth factor II mRNA-binding protein (ImpM) and Bmdsx. All examined females showed a lower inducibility of vitellogenin synthesis and exhibited abnormalities in the ovaries. Testis-like tissues were observed in abnormal ovaries and, notably, the tissues contained considerable numbers of sperm bundles. Homozygous expression of the transgene resulted in formation of the male-specific abdominal segment in adult females and caused partial male differentiation in female genitalia. These results strongly suggest that Masc is an important regulatory gene of maleness in B. mori.

Understanding Natural Silks and Their Integration into Composites

Science.gov (United States)

2012-02-01

Bombyx   mori ...nonwoven  composite  model  based  on  silkworm  cocoon   ( Bombyx   mori ),  Journal  of  Materials  Science  and  Engineering...structural   parameters   to   describe   composition   and   morphology.   Thus,   a   model   originally  

Lack of Connection Between Midgut Cell Autophagy Gene Expression and BmCPV Infection in the Midgut of Bombyx mori.

Science.gov (United States)

Yang, Xiaobing; Wu, Suli; Wu, Yongpeng; Liu, Yang; Qian, Yonghua; Jiao, Feng

2015-01-01

Autophagy is associated with multiple biological processes and has protective and defensive functions with respect to immunity, inflammation, and resistance to microbial infection. In this experiment, we wished to investigate whether autophagy is a factor in the midgut cell response of Bombyx mori to infection by the B. mori cytoplasmic polyhedrosis virus (BmCPV). Our results indicated that the expression of three autophagy-related genes (BmAtg8, BmAtg5, and BmAtg7) in the midgut did not change greatly after BmCPV infection in B. mori. Basal ATG8/ATG8PE protein expression was detected in different B. mori tissues by using western blot analysis. Immunohistochemistry showed that the ATG8/ATG8PE proteins were located mainly in the cytoplasm. ATG8/ATG8PE protein levels decreased at 12 and 16 h after BmCPV infection. Our results indicate that autophagy responded slightly to BmCPV infection, but could not prevent the invasion and replication of the virus. © The Author 2015. Published by Oxford University Press on behalf of the Entomological Society of America.

Machine-Washable PEDOT:PSS Dyed Silk Yarns for Electronic Textiles.

Science.gov (United States)

Ryan, Jason D; Mengistie, Desalegn Alemu; Gabrielsson, Roger; Lund, Anja; Müller, Christian

2017-03-15

Durable, electrically conducting yarns are a critical component of electronic textiles (e-textiles). Here, such yarns with exceptional wear and wash resistance are realized through dyeing silk from the silkworm Bombyx mori with the conjugated polymer:polyelectrolyte complex PEDOT:PSS. A high Young's modulus of approximately 2 GPa combined with a robust and scalable dyeing process results in up to 40 m long yarns that maintain their bulk electrical conductivity of approximately 14 S cm -1 when experiencing repeated bending stress as well as mechanical wear during sewing. Moreover, a high degree of ambient stability is paired with the ability to withstand both machine washing and dry cleaning. For the potential use for e-textile applications to be illustrated, an in-plane thermoelectric module that comprises 26 p-type legs is demonstrated by embroidery of dyed silk yarns onto a piece of felted wool fabric.

Identification of key uric acid synthesis pathway in a unique mutant silkworm Bombyx mori model of Parkinson's disease.

Directory of Open Access Journals (Sweden)

Hiroko Tabunoki

Full Text Available Plasma uric acid (UA levels decrease following clinical progression and stage development of Parkinson's disease (PD. However, the molecular mechanisms underlying decreases in plasma UA levels remain unclear, and the potential to apply mutagenesis to a PD model has not previously been discovered. We identified a unique mutant of the silkworm Bombyx mori (B.mori op. Initially, we investigated the causality of the phenotypic "op" by microarray analysis using our constructed KAIKO functional annotation pipeline. Consequently, we found a novel UA synthesis-modulating pathway, from DJ-1 to xanthine oxidase, and established methods for large-scale analysis of gene expression in B. mori. We found that the mRNA levels of genes in this pathway were significantly lower in B. mori op mutants, indicating that downstream events in the signal transduction cascade might be prevented. Additionally, levels of B.mori tyrosine hydroxylase (TH and DJ-1 mRNA were significantly lower in the brain of B. mori op mutants. UA content was significantly lower in the B. mori op mutant tissues and hemolymph. The possibility that the B. mori op mutant might be due to loss of DJ-1 function was supported by the observed vulnerability to oxidative stress. These results suggest that UA synthesis, transport, elimination and accumulation are decreased by environmental oxidative stress in the B. mori op mutant. In the case of B. mori op mutants, the relatively low availability of UA appears to be due both to the oxidation of DJ-1 and to its expenditure to mitigate the effects of environmental oxidative stress. Our findings are expected to provide information needed to elucidate the molecular mechanism of decreased plasma UA levels in the clinical stage progression of PD.

Feeding response of the silkworm, Bombyx mori, to UV irradiation of mulberry leaves

International Nuclear Information System (INIS)

Yazawa, M.; Shimizu, T.; Hirao, T.

1992-01-01

Ultraviolet irradiation of mulberry leaves caused a reduced feeding response in Bombyx mori larvae (ca. 22% reduction in consumption as compared with control). Sucrose content of the foliage decreased after exposure to UV irradiation (0.5 mW/cm 2 ) for 1 hr. Electrophysiological responses of the sensilla styloconica-I to sucrose concentration (ca. 0-80 mg/g) showed a reduced response to UV-irradiated foliage when compared with the control. From feeding, gustatory, and electrophysiological responses, as well as the measurement of sucrose contents of the leaves, we concluded that the reduced feeding response to UV-irradiated leaves is due to the reduced sucrose content of the mulberry leaves, thus reducing pleogostimulatory levels

Silk film biomaterials for ocular surface repair

Science.gov (United States)

Lawrence, Brian David

Current biomaterial approaches for repairing the cornea's ocular surface upon injury are partially effective due to inherent material limitations. As a result there is a need to expand the biomaterial options available for use in the eye, which in turn will help to expand new clinical innovations and technology development. The studies illustrated here are a collection of work to further characterize silk film biomaterials for use on the ocular surface. Silk films were produced from regenerated fibroin protein solution derived from the Bombyx mori silkworm cocoon. Methods of silk film processing and production were developed to produce consistent biomaterials for in vitro and in vivo evaluation. A wide range of experiments was undertaken that spanned from in vitro silk film material characterization to in vivo evaluation. It was found that a variety of silk film properties could be controlled through a water-annealing process. Silk films were then generated that could be use in vitro to produce stratified corneal epithelial cell sheets comparable to tissue grown on the clinical standard substrate of amniotic membrane. This understanding was translated to produce a silk film design that enhanced corneal healing in vivo on a rabbit injury model. Further work produced silk films with varying surface topographies that were used as a simplified analog to the corneal basement membrane surface in vitro. These studies demonstrated that silk film surface topography is capable of directing corneal epithelial cell attachment, growth, and migration response. Most notably epithelial tissue development was controllably directed by the presence of the silk surface topography through increasing cell sheet migration efficiency at the individual cellular level. Taken together, the presented findings represent a comprehensive characterization of silk film biomaterials for use in ocular surface reconstruction, and indicate their utility as a potential material choice in the

Characterisation of a desmosterol reductase involved in phytosterol dealkylation in the silkworm, Bombyx mori.

Directory of Open Access Journals (Sweden)

Leonora F Ciufo

Full Text Available Most species of invertebrate animals cannot synthesise sterols de novo and many that feed on plants dealkylate phytosterols (mostly C(29 and C(28 yielding cholesterol (C(27. The final step of this dealkylation pathway involves desmosterol reductase (DHCR24-catalysed reduction of desmosterol to cholesterol. We now report the molecular characterisation in the silkworm, Bombyx mori, of such a desmosterol reductase involved in production of cholesterol from phytosterol, rather than in de novo synthesis of cholesterol. Phylogenomic analysis of putative desmosterol reductases revealed the occurrence of various clades that allowed for the identification of a strong reductase candidate gene in Bombyx mori (BGIBMGA 005735. Following PCR-based cloning of the cDNA (1.6 kb and its heterologous expression in Saccharomyces cerevisae, the recombinant protein catalysed reduction of desmosterol to cholesterol in an NADH- and FAD-dependent reaction.Conceptual translation of the cDNA, that encodes a 58.9 kDa protein, and database searching, revealed that the enzyme belongs to an FAD-dependent oxidoreductase family. Western blotting revealed reductase protein expression exclusively in the microsomal subcellular fraction and primarily in the gut. The protein is peripherally associated with microsomal membranes. 2D-native gel and PAGE analysis revealed that the reductase is part of a large complex with molecular weight approximately 250 kDa. The protein occurs in midgut microsomes at a fairly constant level throughout development in the last two instars, but is drastically reduced during the wandering stage in preparation for metamorphosis. Putative Broad Complex transcription factor-binding sites detectable upstream of the DHCR24 gene may play a role in this down-regulation.

Characterisation of a Desmosterol Reductase Involved in Phytosterol Dealkylation in the Silkworm, Bombyx mori

Science.gov (United States)

Ciufo, Leonora F.; Murray, Patricia A.; Thompson, Anu; Rigden, Daniel J.; Rees, Huw H.

2011-01-01

Most species of invertebrate animals cannot synthesise sterols de novo and many that feed on plants dealkylate phytosterols (mostly C29 and C28) yielding cholesterol (C27). The final step of this dealkylation pathway involves desmosterol reductase (DHCR24)-catalysed reduction of desmosterol to cholesterol. We now report the molecular characterisation in the silkworm, Bombyx mori, of such a desmosterol reductase involved in production of cholesterol from phytosterol, rather than in de novo synthesis of cholesterol. Phylogenomic analysis of putative desmosterol reductases revealed the occurrence of various clades that allowed for the identification of a strong reductase candidate gene in Bombyx mori (BGIBMGA 005735). Following PCR-based cloning of the cDNA (1.6 kb) and its heterologous expression in Saccharomyces cerevisae, the recombinant protein catalysed reduction of desmosterol to cholesterol in an NADH- and FAD- dependent reaction. Conceptual translation of the cDNA, that encodes a 58.9 kDa protein, and database searching, revealed that the enzyme belongs to an FAD-dependent oxidoreductase family. Western blotting revealed reductase protein expression exclusively in the microsomal subcellular fraction and primarily in the gut. The protein is peripherally associated with microsomal membranes. 2D-native gel and PAGE analysis revealed that the reductase is part of a large complex with molecular weight approximately 250kDa. The protein occurs in midgut microsomes at a fairly constant level throughout development in the last two instars, but is drastically reduced during the wandering stage in preparation for metamorphosis. Putative Broad Complex transcription factor-binding sites detectable upstream of the DHCR24 gene may play a role in this down-regulation. PMID:21738635

BmICE-2 is a novel pro-apoptotic caspase involved in apoptosis in the silkworm, Bombyx mori.

Science.gov (United States)

Yi, Hua-Shan; Pan, Cai-Xia; Pan, Chun; Song, Juan; Hu, Yan-Fen; Wang, La; Pan, Min-Hui; Lu, Cheng

2014-02-28

In this study we identified a potential pro-apoptotic caspase gene, Bombyx mori(B. mori)ICE-2 (BmICE-2) which encoded a polypeptide of 284 amino acid residues, including a (169)QACRG(173) sequence which surrounded the catalytic site and contained a p20 and a p10 domain. BmICE-2 expressed in Escherichia coli (E. coli) exhibited high proteolytic activity for the synthetic human initiator caspase-9 substrates Ac-LEHD-pNA, but little activity towards the effector caspase-3 substrates Ac-DEVD-pNA. When BmICE-2 was transiently expressed in BmN-SWU1 silkworm B. mori cells, we found that the high proteolytic activity for Ac-LEHD-pNA triggered caspase-3-like protease activity resulting in spontaneous cleavage and apoptosis in these cells. This effect was not replicated in Spodoptera frugiperda 9 cells. In addition, spontaneous cleavage of endogenous BmICE-2 in BmN-SWU1 cells could be induced by actinomycin D. These results suggest that BmICE-2 may be a novel pro-apoptotic gene with caspase-9 activity which is involved apoptotic processes in BmN-SWU1 silkworm B. mori cells. Copyright © 2014 Elsevier Inc. All rights reserved.

Development and reproduction of Podisus distinctus (Heteroptera: Pentatomidae) fed on larva of Bombyx mori (Lepidoptera: Bombycidae).

Science.gov (United States)

Lacerda, M C; Ferreira, A M R M; Zanuncio, T V; Zanuncio, J C; Bernardino, A S; Espindula, M C

2004-05-01

Biological control has been reducing the use of chemical products against insect pests, especially predatory Pentatomidae. Species of this group can present high variations in their life cycle as a result of their diet. Thus, the objective of this research was to study nymph development and reproduction of Podisus distinctus (Stäl, 1860) (Heteroptera: Pentatomidae) fed on Bombyx mori L., 1758 (Lepidoptera: Bombycidae) larvae (T1), compared to those fed on Tenebrio molitor L., 1758 (Coleoptera: Tenebrionidae) (T2) and Musca domestica L., 1758 (Diptera: Muscidae) larvae (T3) at a temperature of 25 +/- 0.5 degrees C, relative humidity of 70 +/- 2%, and photophase of 12 h. Predators fed on B. mori showed duration of the nymph phase (18.68 +/- 1.02) similar to those fed on T. molitor (18.32 +/- 1.49). Pre-oviposition and oviposition periods and number of egg masses, besides eggs and nymphs per female, were higher with B. mori (5.83 +/- 2.02; 15.00 +/- 7.40; 8.42 +/- 1.84; 296.69 +/- 154.75; and 228.55 +/- 141.04, respectively) while longevity of males and females of P. distinctus was 25.76 +/- 16.15 and 35.00 +/- 16.15 days with T. molitor, and 20.57 +/- 13.60 and 23.46 +/- 12.35 days with B. mori, respectively.

The effect of gamma irradiation on some morphological and quantitative changes of Bombyx mori L. silk gland

International Nuclear Information System (INIS)

Petkov, N.; Malinova, K.; Binkh, N.

1996-01-01

A study to determine the effect of gamma irradiation of silkworm eggs at doses of 1.00; 2.00 and 3.00 on silk gland weight, length and width is performed. It was found that gamma irradiation of eggs in the stage of embryo most intensive growth in length (B 2 ) at doses 2.00 and 3.00 Gy stimulates increasing of silk glands weight in silkworms on the fifth day instar by 12-25 mg, as well as the silk worm width - by 7-33 μm, which is of significant importance for the synthesis and secretion of silk proteins (fibroin and sericin). A breed specificity was also observed

Effects of BmCPV Infection on Silkworm Bombyx mori Intestinal Bacteria.

Directory of Open Access Journals (Sweden)

Zhenli Sun

Full Text Available The gut microbiota has a crucial role in the growth, development and environmental adaptation in the host insect. The objective of our work was to investigate the microbiota of the healthy silkworm Bombyx mori gut and changes after the infection of B. mori cypovirus (BmCPV. Intestinal contents of the infected and healthy larvae of B. mori of fifth instar were collected at 24, 72 and 144 h post infection with BmCPV. The gut bacteria were analyzed by pyrosequencing of the 16S rRNA gene. 147(135 and 113(103 genera were found in the gut content of the healthy control female (male larvae and BmCPV-infected female (male larvae, respectively. In general, the microbial communities in the gut content of healthy larvae were dominated by Enterococcus, Delftia, Pelomonas, Ralstonia and Staphylococcus, however the abundance change of each genus was depended on the developmental stage and gender. Microbial diversity reached minimum at 144 h of fifth instar larvae. The abundance of Enterococcus in the females was substantially lower and the abundance of Delftia, Aurantimonas and Staphylococcus was substantially higher compared to the males. Bacterial diversity in the intestinal contents decreased after post infection with BmCPV, whereas the abundance of both Enterococcus and Staphylococcus which belongs to Gram-positive were increased. Therefore, our findings suggested that observed changes in relative abundance was related to the immune response of silkworm to BmCPV infection. Relevance analysis of plenty of the predominant genera showed the abundance of the Enterococcus genus was in negative correlation with the abundance of the most predominant genera. These results provided insight into the relationship between the gut microbiota and development of the BmCPV-infected silkworm.

A Review of the Implications of Heterozygosity and Inbreeding on Germplasm Biodiversity and Its Conservation in the Silkworm, Bombyx mori

Science.gov (United States)

Jingade, A.H.; Vijayan, K.; Somasundaram, P.; Srivasababu, G.K.; Kamble, C.K.

2011-01-01

Silkworm genebanks assume paramount importance as the reservoirs of biodiversity and source of alleles that can be easily retrieved for genetic enhancement of popular breeds. More than 4000 Bombyx mori L (Lepidoptera: Bombycidae) strains are currently available and these strains are maintained through continuous sibling mating. This repeated sibling mating makes the populations of each strain more homozygous, but leads to loss of unique and valuable genes through the process of inbreeding depression. Hence, it is essential to maintain a minimal degree of heterozygosity within the population of each silkworm strain, especially in the traditional geographic strains, to avoid such loss. As a result, accurate estimation of genetic diversity is becoming more important in silkworm genetic resources conservation. Application of molecular markers help estimate genetic diversity much more accurately than that of morphological traits. Since a minimal amount of heterozygosity in each silkworm strain is essential for better conservation by avoiding inbreeding depression, this article overviews both theoretical and practical importance of heterozygosity together with impacts of inbreeding depression and the merits and demerits of neutral molecular markers for measurements of both heterozygosity and inbreeding depression in the silkworm Bombyx mori. PMID:21521139

Biological characteristics of Trichospilus diatraeae (Hymenopetra: Eulophidae in the hosts Bombyx mori (Lepidoptera: Bombycidae and Diatraea saccharalis (Lepidoptera: Crambidae

Directory of Open Access Journals (Sweden)

Vanessa Rodrigues Ferreira Calado

2014-03-01

Full Text Available Trichospilus diatraeae Cherian & Margabandhu, 1942 (Hymenoptera: Eulophidae is a pupal endoparasitoid of lepidoptera and it has been studied as a potential agent for biological control of pests. For developing techniques to breed parasitoids, there is a need to choose the appropriate alternative host, thus, this article aims to evaluate the biological characteristics of T. diatraeae with regard to the hosts Bombyx mori Linneaus (Lepidoptera: Bombycidae and Diatraea saccharalis (Fabricius (Lepidoptera: Crambidae, in laboratory. Twelve pupae of B. mori and twelve pupae of D. saccharalis, within 72 and 24 h of life, respectively, were exposed to parasitism by 21 female parasitoids at 25 ± 1°C, with relative humidity 70 ± 10% and photophase of 14 h. Life-cycle duration (egg – adult of T. diatraeae was 19.44 ± 0.12 days in pupae of D. saccharalis and 18.00 ± 0.05 days in pupae of B. mori, the emergence of parasitoid progeny was 66.60% in pupae of D. saccharalis, and 75.00% in pupae of B. mori. The progeny of T. diatraeae was 354.50 ± 43.21 per pupa of D. saccharalis and 469.11 ± 15.19 per pupa of B. mori. Trichospilus diatraeae showed suitability to the host and its ability to parasitize various hosts.

Sem study on the invasion of Nomuraea rileyi (Farlow) on silkworm, Bombyx mori Linn. causing green muscardine.

Science.gov (United States)

Kumar, V; Singh, G P; Kumar, V; Babu, A M; Datta, R K

1997-01-01

The mature conidia of Nomuraea rileyi (Farlow) germinate on the larval integument of Bombyx mori within 24 h and penetrate the cuticle within 36 h after inoculation at 24.0 +/- 1.0 degrees C temperature and 80.0 +/- 5.0% relative humidity. The penetrating hyphae multiply by budding and septa formation in the hemocoel, and the larva succumbs to the infection 6-7 days post-treatment. The hyphal bodies elongate and become interwoven with other hyphae forming a mycelial complex across different tissues. The ramification of hyphae along the epidermal tissue results in larval mummification in 7-8 days. Numerous conidiophores emerge, producing a confluent white fungal mat over the entire surface of the host larva by 9-10 days. Pale green conidia develop, making the larval body green. Life cycle of the fungus on B. mori is completed in 10-11 days.

Hygroscopics and yield characteristics of cocoon in races of Bombyx mori L.

Directory of Open Access Journals (Sweden)

Antonio José Porto

2012-01-01

Full Text Available Cocoons, cocoon shells and chrysalis of four races of Bombyx mori L., two from China (C202 and C212 and two from Japan (B104 and M11-2, were analyzed in function of determinant factors as weight (dry mater and moisture and by hygroscopic capacity after cooking. It was used a complete randomized design, with four treatments and ten replications. Although the cocoon shell has a higher hygroscopic capacity, the percentage of water in the chrysalis is the main factor to determine the weight of cocoon. The percentage of water in the cocoon and its components are inversely related to the absorption after cooking. Of all races evaluated, the chinese ones had lower percentage of water in the cocoon and higher cocoon shell weight than the japanese races.

Expression analysis of several antiviral related genes to BmNPV in different resistant strains of silkworm, Bombyx mori.

Science.gov (United States)

Cheng, Yang; Wang, Xue-yang; Du, Chang; Gao, Juan; Xu, Jia-ping

2014-05-30

Bombyx mori L. (Lepidoptera: Bombycidae) nucleopolyhedrovirus (BmNPV) is a highly pathogenic virus in the sericultural industry, often causing severe damage leading to large economic losses. The immune mechanisms of B. mori against this virus remain obscure. Previous studies had demonstrated Bmlipase-1, BmNox and Bmserine protease-2 showing antiviral activity in vitro, but data on the transcription levels of these proteins in different resistant strains were not reported. In order to determine the resistance level of the four different strains (P50, A35, A40, A53) and gain a better understanding of the mechanism of resistance to BmNPV in B. mori, the relative expression level of the genes coding the three antiviral proteins in larval haemolymph and midgut of different B. mori strains resistant to BmNPV was determined. The results showed that these genes expressed significantly higher in the resistant strains compared to the susceptible strain, and the differential expression levels were consistent with the LC50 values in different strains. The transcription level of the target genes almost all up-regulated in the larvae midgut and down-regulated in the haemolymph. The results indicate the correlation of these genes to BmNPV resistance in B. mori. This is an open access paper. We use the Creative Commons Attribution 3.0 license that permits unrestricted use, provided that the paper is properly attributed.

A highly divergent gene cluster in honey bees encodes a novel silk family.

Science.gov (United States)

Sutherland, Tara D; Campbell, Peter M; Weisman, Sarah; Trueman, Holly E; Sriskantha, Alagacone; Wanjura, Wolfgang J; Haritos, Victoria S

2006-11-01

The pupal cocoon of the domesticated silk moth Bombyx mori is the best known and most extensively studied insect silk. It is not widely known that Apis mellifera larvae also produce silk. We have used a combination of genomic and proteomic techniques to identify four honey bee fiber genes (AmelFibroin1-4) and two silk-associated genes (AmelSA1 and 2). The four fiber genes are small, comprise a single exon each, and are clustered on a short genomic region where the open reading frames are GC-rich amid low GC intergenic regions. The genes encode similar proteins that are highly helical and predicted to form unusually tight coiled coils. Despite the similarity in size, structure, and composition of the encoded proteins, the genes have low primary sequence identity. We propose that the four fiber genes have arisen from gene duplication events but have subsequently diverged significantly. The silk-associated genes encode proteins likely to act as a glue (AmelSA1) and involved in silk processing (AmelSA2). Although the silks of honey bees and silkmoths both originate in larval labial glands, the silk proteins are completely different in their primary, secondary, and tertiary structures as well as the genomic arrangement of the genes encoding them. This implies independent evolutionary origins for these functionally related proteins.

Biobased silver nanocolloid coating on silk fibers for prevention of post-surgical wound infections

Directory of Open Access Journals (Sweden)

Dhas SP

2015-10-01

Full Text Available Sindhu Priya Dhas, Suruthi Anbarasan, Amitava Mukherjee, Natarajan Chandrasekaran Center for Nanobiotechnology, VIT University, Vellore, India Abstract: Bombyx mori silk fibers are an important biomaterial and are used in surgical sutures due to their remarkable biocompatibility. The major drawback to the application of biomaterials is the risk of bacterial invasion, leading to clinical complications. We have developed an easy and cost-effective method for fabrication of antibacterial silk fibers loaded with silver nanoparticles (AgNPs by an in situ and ex situ process using an aqueous extract of Rhizophora apiculata leaf. Scanning electron microscopy revealed that well dispersed nanoparticles impregnated the silk fibers both in situ and ex situ. The crystalline nature of the AgNPs in the silk fibers was demonstrated by X-ray diffraction. The thermal and mechanical properties of the silk fibers were enhanced after they were impregnated with AgNPs. The silver-coated silk fibers fabricated by the in situ and ex situ method exhibited more than 90% inhibition against Pseudomonas aeruginosa and Staphylococcus aureus. Silk fibers doped with AgNPs were found to be biocompatible with 3T3 fibroblasts. The results obtained represent an important advance towards the clinical application of biocompatible AgNP-loaded silk fibers for prevention of surgical wound infections. Keywords: silk fibers, silver nanoparticles, antibacterial activity, wound infections, cytotoxicity, 3T3 fibroblast cells

Genome-Wide Identification of Polycomb Target Genes Reveals a Functional Association of Pho with Scm in Bombyx mori

OpenAIRE

Li, Zhiqing; Cheng, Daojun; Mon, Hiroaki; Tatsuke, Tsuneyuki; Zhu, Li; Xu, Jian; Lee, Jae Man; Xia, Qingyou; Kusakabe, Takahiro

2012-01-01

Polycomb group (PcG) proteins are evolutionarily conserved chromatin modifiers and act together in three multimeric complexes, Polycomb repressive complex 1 (PRC1), Polycomb repressive complex 2 (PRC2), and Pleiohomeotic repressive complex (PhoRC), to repress transcription of the target genes. Here, we identified Polycomb target genes in Bombyx mori with holocentric centromere using genome-wide expression screening based on the knockdown of BmSCE, BmESC, BmPHO, or BmSCM gene, which represent ...

Structure and morphology of regenerated silk nano-fibers produced by electrospinning

Science.gov (United States)

Zarkoob, Shahrzad

The impressive physical and mechanical properties of natural silk fiberssp1 and the possibility of producing these proteins using biotechnology,sp2 have provided the impetus for recent efforts in both the biosynthesissp{3,4} and the spinning of these protein based biopolymers.sp{5,6,7} The question still remains: whether fibers spun from solutions with similar chemical makeup can produce fibers with similar structures and therefore with the possibility of improved properties. Since genetically engineered silk solutions were not readily available, the first objective of this project was to completely dissolve the Bombyx mori cocoon and the Nephila clavipes dragline silk while maintaining the molecular weight integrity of the polymer. The second objective was to develop a system for re-spinning from very small amount of the resulting silk solutions by the process of electrospinning. The third objective was, to produce regenerated silk fibers with diameters that are several orders of magnitude smaller than the original fibers, suitable for direct observation and analysis by transmission electron microscopy and electron diffraction. And finally, to compare these results to structural information obtained from natural (as spun by the organism) fibers to see if the regenerated solutions are able to form the same structure as the original fibers. Both types of silk fibers were successfully dissolved while maintaining the polymer integrity. Small quantities (25-50 mul) of these solutions were used to electrospin fibers with diameters ranging from 8nm-200nm. The fibers were observed by optical, scanning electron, and transmission electron microscopy. These nano fibers showed optical retardation, appeared to have a circular cross-section, and were dimensionally stable at temperatures above 280sp°C. Electron diffraction patterns of annealed electrospun fibers of B. mori and N. clavipes showed reflections, demonstrating orientational and semicrystalline order in the material

Standard method for detecting Bombyx mori nucleopolyhedrovirus disease-resistant silkworm varieties

Directory of Open Access Journals (Sweden)

Yang Qiong

Full Text Available ABSTRACT Bombyx mori nucleopolyhedrovirus (BmNPV disease is one of the most serious silkworm diseases, and it has caused great economic losses to the sericulture industry. So far, the disease has not been controlled effectively by therapeutic agents. Breeding resistant silkworm varieties breeding may be an effective way to improve resistance to BmNPV and reduce economic losses. A precise resistance-detection method will help to accelerate the breeding process. For this purpose, here we described the individual inoculation method (IIM. Details of the IIM include pathogen BmNPV preparation, mulberry leaf size, pathogen volume, rearing conditions, course of infection, and breeding conditions. Finally, a resistance comparison experiment was performed using the IIM and the traditional group inoculation method (GIM. The incidence of BmNPV infection and the within-group variance results showed that the IIM was more precise and reliable than the GIM.

Bombyx mori L.

Indian Academy of Sciences (India)

Unknown

Qualitative and quantitative differences in proteins expressed in the middle silkglands of male and female silk- worm larvae ... dimension and according to size (Mr) by SDS-PAGE in ... immediately as the original protein extraction sample for.

Female sex pheromone and male behavioral responses of the bombycid moth Trilocha varians: comparison with those of the domesticated silkmoth Bombyx mori

Science.gov (United States)

Daimon, Takaaki; Fujii, Takeshi; Yago, Masaya; Hsu, Yu-Feng; Nakajima, Yumiko; Fujii, Tsuguru; Katsuma, Susumu; Ishikawa, Yukio; Shimada, Toru

2012-03-01

Analysis of female sex pheromone components and subsequent field trap experiments demonstrated that the bombycid moth Trilocha varians uses a mixture of ( E, Z)-10,12-hexadecadienal (bombykal) and ( E,Z)-10,12-hexadecadienyl acetate (bombykyl acetate) as a sex pheromone. Both of these components are derivatives of ( E,Z)-10,12-hexadecadienol (bombykol), the sex pheromone of the domesticated silkmoth Bombyx mori. This finding prompted us to compare the antennal and behavioral responses of T. varians and B. mori to bombykol, bombykal, and bombykyl acetate in detail. The antennae of T. varians males responded to bombykal and bombykyl acetate but not to bombykol, and males were attracted only when lures contained both bombykal and bombykyl acetate. In contrast, the antennae of B. mori males responded to all the three components. Behavioral analysis showed that B. mori males responded to neither bombykal nor bombykyl acetate. Meanwhile, the wing fluttering response of B. mori males to bombykol was strongly inhibited by bombykal and bombykyl acetate, thereby indicating that bombykal and bombykyl acetate act as behavioral antagonists for B. mori males. T. varians would serve as a reference species for B. mori in future investigations into the molecular mechanisms underlying the evolution of sex pheromone communication systems in bombycid moths.

Selection of reference genes for tissue/organ samples on day 3 fifth-instar larvae in silkworm, Bombyx mori.

Science.gov (United States)

Wang, Genhong; Chen, Yanfei; Zhang, Xiaoying; Bai, Bingchuan; Yan, Hao; Qin, Daoyuan; Xia, Qingyou

2018-06-01

The silkworm, Bombyx mori, is one of the world's most economically important insect. Surveying variations in gene expression among multiple tissue/organ samples will provide clues for gene function assignments and will be helpful for identifying genes related to economic traits or specific cellular processes. To ensure their accuracy, commonly used gene expression quantification methods require a set of stable reference genes for data normalization. In this study, 24 candidate reference genes were assessed in 10 tissue/organ samples of day 3 fifth-instar B. mori larvae using geNorm and NormFinder. The results revealed that, using the combination of the expression of BGIBMGA003186 and BGIBMGA008209 was the optimum choice for normalizing the expression data of the B. mori tissue/organ samples. The most stable gene, BGIBMGA003186, is recommended if just one reference gene is used. Moreover, the commonly used reference gene encoding cytoplasmic actin was the least appropriate reference gene of the samples investigated. The reliability of the selected reference genes was further confirmed by evaluating the expression profiles of two cathepsin genes. Our results may be useful for future studies involving the quantification of relative gene expression levels of different tissue/organ samples in B. mori. © 2018 Wiley Periodicals, Inc.

Nitric oxide synthase during early embryonic development in silkworm Bombyx mori: Gene expression, enzyme activity, and tissue distribution.

Science.gov (United States)

Kitta, Ryo; Kuwamoto, Marina; Yamahama, Yumi; Mase, Keisuke; Sawada, Hiroshi

2016-12-01

To elucidate the mechanism for embryonic diapause or the breakdown of diapause in Bombyx mori, we biochemically analyzed nitric oxide synthase (NOS) during the embryogenesis of B. mori. The gene expression and enzyme activity of B. mori NOS (BmNOS) were examined in diapause, non-diapause, and HCl-treated diapause eggs. In the case of HCl-treated diapause eggs, the gene expression and enzyme activity of BmNOS were induced by HCl treatment. However, in the case of diapause and non-diapause eggs during embryogenesis, changes in the BmNOS activity and gene expressions did not coincide except 48-60 h after oviposition in diapause eggs. The results imply that changes in BmNOS activity during the embryogenesis of diapause and non-diapause eggs are regulated not only at the level of transcription but also post-transcription. The distribution and localization of BmNOS were also investigated with an immunohistochemical technique using antibodies against the universal NOS; the localization of BmNOS was observed mainly in the cytoplasm of yolk cells in diapause eggs and HCl-treated diapause eggs. These data suggest that BmNOS has an important role in the early embryonic development of the B. mori. © 2016 Japanese Society of Developmental Biologists.

The gene expression profile of resistant and susceptible Bombyx mori strains reveals cypovirus-associated variations in host gene transcript levels.

Science.gov (United States)

Guo, Rui; Wang, Simei; Xue, Renyu; Cao, Guangli; Hu, Xiaolong; Huang, Moli; Zhang, Yangqi; Lu, Yahong; Zhu, Liyuan; Chen, Fei; Liang, Zi; Kuang, Sulan; Gong, Chengliang

2015-06-01

High-throughput paired-end RNA sequencing (RNA-Seq) was performed to investigate the gene expression profile of a susceptible Bombyx mori strain, Lan5, and a resistant B. mori strain, Ou17, which were both orally infected with B. mori cypovirus (BmCPV) in the midgut. There were 330 and 218 up-regulated genes, while there were 147 and 260 down-regulated genes in the Lan5 and Ou17 strains, respectively. Gene ontology (GO) enrichment and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment for differentially expressed genes (DEGs) were carried out. Moreover, gene interaction network (STRING) analyses were performed to analyze the relationships among the shared DEGs. Some of these genes were related and formed a large network, in which the genes for B. mori cuticular protein RR-2 motif 123 (BmCPR123) and the gene for B. mori DNA replication licensing factor Mcm2-like (BmMCM2) were key genes among the common up-regulated DEGs, whereas the gene for B. mori heat shock protein 20.1 (Bmhsp20.1) was the central gene among the shared down-regulated DEGs between Lan5 vs Lan5-CPV and Ou17 vs Ou17-CPV. These findings established a comprehensive database of genes that are differentially expressed in response to BmCPV infection between silkworm strains that differed in resistance to BmCPV and implied that these DEGs might be involved in B. mori immune responses against BmCPV infection.

Development and reproduction of Podisus distinctus (Heteroptera: Pentatomidae fed on larva of Bombyx mori (Lepidoptera: Bombycidae

Directory of Open Access Journals (Sweden)

M. C. Lacerda

Full Text Available Biological control has been reducing the use of chemical products against insect pests, specially predatory Pentatomidae. Species of this group can present high variations in their life cycle as a result of their diet. Thus, the objective of this research was to study nymph development and reproduction of Podisus distinctus (Stäl, 1860 (Heteroptera: Pentatomidae fed on Bombyx mori L., 1758 (Lepidoptera: Bombycidae larvae (T1, compared to those fed on Tenebrio molitor L., 1758 (Coleoptera: Tenebrionidae (T2 and Musca domestica L., 1758 (Diptera: Muscidae larvae (T3 at a temperature of 25 ± 0.5ºC, relative humidity of 70 ± 2%, and photophase of 12 h. Predators fed on B. mori showed duration of the nymph phase (18.68 ± 1.02 similar to those fed on T. molitor (18.32 ± 1.49. Pre-oviposition and oviposition periods and number of egg masses, besides eggs and nymphs per female, were higher with B. mori (5.83 ± 2.02; 15.00 ± 7.40; 8.42 ± 1.84; 296.69 ± 154.75; and 228.55 ± 141.04, respectively while longevity of males and females of P. distinctus was 25.76 ± 16.15 and 35.00 ± 16.15 days with T. molitor, and 20.57 ± 13.60 and 23.46 ± 12.35 days with B. mori, respectively.

BmDredd is an initiator caspase and participates in Emodin-induced apoptosis in the silkworm, Bombyx mori.

Science.gov (United States)

Wang, La; Song, Juan; Bao, Xi-Yan; Chen, Peng; Yi, Hua-Shan; Pan, Min-Hui; Lu, Cheng

2016-10-15

The identification and analysis of the caspases is essential to research into apoptosis in lepidoptera insects. The domesticated silkworm, Bombyx mori, is the model system for lepidopterans. In this study, we cloned and characterized a B. mori Dredd gene, BmDredd, the proposed insect homologue of human caspase-8, which encoded a polypeptide of 543 amino acids. BmDredd possesses a long N-terminal prodomain, a p20 domain, and a p10 domain. When transiently expressed in Escherichia coli cells, BmDredd underwent spontaneous cleavage and exhibited high proteolytic activity for caspase-8 substrate but relatively low for caspase-3 or -9 substrate. In addition, BmDredd induced apoptosis when transiently expressed in BmN-SWU1 cells, an ovarian cell line of B. mori. Moreover, after the treatment of Emodin, a novel apoptosis inducer, endogenous BmDredd expression level, the caspase-8 activity and the apoptotic rate increased notably in BmN-SWU1 cells. When BmDredd was subjected to interference in BmN-SWU1 cells and Emodin treatment, BmDredd expression levels decreased and the apoptotic rate also decreased significantly. These results suggest BmDredd is the homologue of human caspase-8 and plays a role in Emodin-induced apoptosis in BmN-SWU1 cells of B. mori. Copyright © 2016 Elsevier B.V. All rights reserved.

Localization and functional analysis of the insect-specific RabX4 in the brain of Bombyx mori.

Science.gov (United States)

Uno, Tomohide; Furutani, Masayuki; Sakamoto, Katsuhiko; Uno, Yuichi; Kanamaru, Kengo; Mizoguchi, Akira; Hiragaki, Susumu; Takeda, Makio

2017-09-01

Rab proteins are small monomeric GTPases/GTP-binding proteins, which form the largest branch of the Ras superfamily. The different Rab GTPases are localized to the cytosolic face of specific intracellular membranes, where they function as regulators of distinct steps in membrane trafficking. RabX4 is an insect-specific Rab protein that has no close homolog in vertebrates. There is little information about insect-specific Rab proteins. RabX4 was expressed in Escherichia coli and subsequently purified. Antibodies against Bombyx mori RabX4 were produced in rabbits for western immunoblotting and immunohistochemistry. Western blotting of neural tissues revealed a single band, at approximately 26 kD. RabX4-like immunohistochemical reactivity was restricted to neurons of the pars intercerebralis and dorsolateral protocerebrum in the brain. Further immunohistochemical analysis revealed that RabX4 colocalized with Rab6 and bombyxin in the corpus allatum, a neuronal organ that secretes neuropeptides synthesized in the brain into the hemolymph. RabX4 expression in the frontal ganglion, part of the insect stomatogastric nervous system that is found in most insect orders, was restricted to two neurons on the outer region and did not colocalize with allatotropin or Rab6. Furthermore, RNA interference of RabX4 decreased bombyxin expression levels in the brain. These findings suggest that RabX4 is involved in the neurosecretion of a secretory organ in Bombyx mori. © 2017 Wiley Periodicals, Inc.

Molecular cloning, characterization and expression analysis of ATG1 in the silkworm, Bombyx mori.

Science.gov (United States)

Casati, Barbara; Terova, Genciana; Cattaneo, Anna Giulia; Rimoldi, Simona; Franzetti, Eleonora; de Eguileor, Magda; Tettamanti, Gianluca

2012-12-15

Atg1 is a Serine/Threonine protein kinase that plays a pivotal role in autophagy. A complete coding sequence of ATG1 is not available for the silkworm, Bombyx mori which is a good model for studying the autophagic process. In the present study we isolated two full-length cDNAs of 2175 (transcript variant A) and 2271 (transcript variant B) bases representing ATG1 in the silkworm. Phylogenetic analysis indicated that BmATG1 was closely related to orthologs of other insects. The encoded BmAtg1 proteins shared extensive homology with orthologs from yeast to mammals, showing high conservation at the N-terminal region where the catalytic domain and ATP- and Mg-binding sites are located. A de novo prediction of the three-dimensional structure for each protein is presented. We used real-time RT-PCR to quantify dynamic changes in mRNA copy number of BmATG1 in the midgut and fat body of fifth instar larvae undergoing starvation, as well as in other tissues of silkworm at the end of last larval instar. Our qPCR results revealed that BmATG1 expression levels at the end of larval life were comparable in the midgut, fat body and Malpighian tubules, while these were higher in the gonads; moreover, the mRNA copy number of ATG1 was very different among the anterior, middle and posterior silk glands. Real-time PCR analysis also showed that starvation significantly influenced BmATG1 mRNA copy number in the fat body of silkworm, inducing an upregulation 24h after food withdrawal, with only a slight effect in the midgut. Low expression levels of BmATG1 were observed in both tissues of control animals up to the second day of spinning phase. Copyright © 2012 Elsevier B.V. All rights reserved.

Radiosurgery using heavy ion microbeams for biological study: Fate mapping of the cellular blastoderm-stage egg of the silkworm, Bombyx mori

International Nuclear Information System (INIS)

Kiguchi, Kenji; Shirai, Koji; Kanekatsu, Rensuke; Kobayashi, Yasuhiko; Tu, Z.-L.; Funayama, Tomoo; Watanabe, Hiroshi

2003-01-01

We investigated the effects of heavy ions on embryogenesis of the silkworm, Bombyx mori using a collimated heavy ion microbeam from the vertical beam line of an AVF-cyclotron. Eggs were exposed to carbon ions at the cellular blastoderm stage. Microbeams were found to be extremely useful for radio-microsurgical inactivation of nuclei or cells in the target site. Spot irradiation caused abnormal embryos, which showed localized defects such as deletion, duplication and fusion, depending on dose, beam size and site of irradiation. The location and frequency of defects on the resultant embryos were closely correlated to the irradiation site. Based on this correlation, a fate map was established for the Bombyx egg at the cellular blastoderm stage

Radiosurgery using heavy ion microbeams for biological study: Fate mapping of the cellular blastoderm-stage egg of the silkworm, Bombyx mori

Energy Technology Data Exchange (ETDEWEB)

Kiguchi, Kenji E-mail: kkiguch@giptc.shinshu-u.ac.jp; Shirai, Koji; Kanekatsu, Rensuke; Kobayashi, Yasuhiko; Tu, Z.-L.; Funayama, Tomoo; Watanabe, Hiroshi

2003-09-01

We investigated the effects of heavy ions on embryogenesis of the silkworm, Bombyx mori using a collimated heavy ion microbeam from the vertical beam line of an AVF-cyclotron. Eggs were exposed to carbon ions at the cellular blastoderm stage. Microbeams were found to be extremely useful for radio-microsurgical inactivation of nuclei or cells in the target site. Spot irradiation caused abnormal embryos, which showed localized defects such as deletion, duplication and fusion, depending on dose, beam size and site of irradiation. The location and frequency of defects on the resultant embryos were closely correlated to the irradiation site. Based on this correlation, a fate map was established for the Bombyx egg at the cellular blastoderm stage.

Expression of matrix metalloproteinase genes during basement membrane degradation in the metamorphosis of Bombyx mori.

Science.gov (United States)

Kawasaki, Hideki; Manickam, Asaithambi; Shahin, Rima; Ote, Manabu; Iwanaga, Masashi

2018-01-05

The present study was conducted to clarify the involvement of the basement membrane (BM) in insect metamorphosis through analysis of the expression profile of two types of metalloproteinase (MMP and ADAMTS) genes in several organs, their ecdysone involvement, and the histological change of BM. BM was observed around wing sac and in the wing cavity and around fat bodies at the W0 stage but disappeared after the W3 stage, and wing discs evaginated and fat body cells scattered after the W3 stage. The disappearance of the BM of midgut and silk glands was not observed after the W3 stage, but degenerated epithelium cells in the midgut and shrunken cells in the silk gland were observed after the W3 stage. BmMMP1 showed a peak at P0 in the wing discs, fat bodies, midgut, and silk gland. BmMMP2 showed a broad peak around pupation in the wing discs, fat bodies, midgut, and silk gland. BmADAMTS-1 showed enhanced expression at W2 in the wing discs, fat bodies, midgut, and hemocyte, while BmADAMTS-L showed enhanced expression at W3 in the fat bodies, midgut, silk gland, and hemocyte. After pupation, they showed a different expression in different organs. All of four genes were induced by 20-hydroxyecdysone in wing discs in vitro. The present results suggested the involvement of MMPs and ADAMTS in the BM digestion and the morphogenesis of organs during Bombyx metamorphosis. Copyright © 2017 Elsevier B.V. All rights reserved.

Expression profiling of Bombyx mori gloverin2 gene and its synergistic antifungal effect with cecropin A against Beauveria bassiana.

Science.gov (United States)

Lü, Dingding; Geng, Tao; Hou, Chengxiang; Qin, Guangxing; Gao, Kun; Guo, Xijie

2017-02-05

Gloverin2 is a cationic and glycine-rich antimicrobial peptide whose expression can be induced in fat body of silkworm (Bombyx mori) larvae exposed to bacteria. The purpose of this study is to identify the roles of Bombyx mori gloverin2 (Bmgloverin2) during entomopathogenic fungus Beauveria bassiana infection. Fluorescent quantitative real-time PCR analysis indicated that the relative expression level of Bmgloverin2 gene was up-regulated in the silkworm larvae infected by B. bassiana. The cDNA of Bmgloverin2 was cloned from the silkworm by RT-PCR and the DNA segment of the Bmgloverin2 peptide (without signal peptide sequence) was inserted into pCzn1 expression plasmid and expressed in E. coli ArcticExpress (DE3). SDS-PAGE results revealed that soluble recombinant Bmgloverin2 was successfully expressed and purified. Polyclonal antibody against the Bmgloverin2 was successfully produced with the expressed recombinant protein. Western blot analysis indicated that Bmgloverin2 could be detected in the fat body of silkworm larvae infected with B. bassiana, suggesting that the expression of Bmgloverin2 could be induced by B. bassiana infection in silkworm. Antifungal assays indicated that the Bmgloverin2 had a synergistic antifungal activity with B. mori cecropin A (BmCecA) to entomopathogenic fungus B. bassiana both in vitro and in vivo in the silkworm larvae. This is the first report that Bmgloverin2 exhibits synergistic effect with BmCecA in antifungal activity against B. bassiana. The study demonstrates that Bmgloverin2 is an antifungal protein which plays an important role in synergistic antifungal activity with other antimicrobial peptide in silkworm. Copyright © 2016 Elsevier B.V. All rights reserved.

Silk Fibroin Aqueous-Based Adhesives Inspired by Mussel Adhesive Proteins.

Science.gov (United States)

Burke, Kelly A; Roberts, Dane C; Kaplan, David L

2016-01-11

Silk fibroin from the domesticated silkworm Bombyx mori is a naturally occurring biopolymer with charged hydrophilic terminal regions that end-cap a hydrophobic core consisting of repeating sequences of glycine, alanine, and serine residues. Taking inspiration from mussels that produce proteins rich in L-3,4-dihydroxyphenylalanine (DOPA) to adhere to a variety of organic and inorganic surfaces, the silk fibroin was functionalized with catechol groups. Silk fibroin was selected for its high molecular weight, tunable mechanical and degradation properties, aqueous processability, and wide availability. The synthesis of catechol-functionalized silk fibroin polymers containing varying amounts of hydrophilic polyethylene glycol (PEG, 5000 g/mol) side chains was carried out to balance silk hydrophobicity with PEG hydrophilicity. The efficiency of the catechol functionalization reaction did not vary with PEG conjugation over the range studied, although tuning the amount of PEG conjugated was essential for aqueous solubility. Adhesive bonding and cell compatibility of the resulting materials were investigated, where it was found that incorporating as little as 6 wt % PEG prior to catechol functionalization resulted in complete aqueous solubility of the catechol conjugates and increased adhesive strength compared with silk lacking catechol functionalization. Furthermore, PEG-silk fibroin conjugates maintained their ability to form β-sheet secondary structures, which can be exploited to reduce swelling. Human mesenchymal stem cells (hMSCs) proliferated on the silks, regardless of PEG and catechol conjugation. These materials represent a protein-based approach to catechol-based adhesives, which we envision may find applicability as biodegradable adhesives and sealants.

Effects of irradiation to larvae of Bombyx mori in relation to nutritional conditions and to moulting

International Nuclear Information System (INIS)

Coulon, M.

1976-01-01

Silkworms (Bombyx mori) were exposed to irradiation in the 1st and 2nd larval instars. The effects, as indicated by mortality or by failure to moult, were studied in relation to a period of starvation (24 hours at 22deg). Before the initiation of feeding, in either instar, the larvae were very resistant to irradiation and fasting did not modify this resistance. Probably this was due to physiological quiescence. After the initiation of feeding, the interposition of a fast either augmented or decreased radiation tolerance, probably according to the phase of the physiological cycle involving feeding and moulting

Identification and functional characterization of a sex pheromone receptor in the silkmoth Bombyx mori

Science.gov (United States)

Sakurai, Takeshi; Nakagawa, Takao; Mitsuno, Hidefumi; Mori, Hajime; Endo, Yasuhisa; Tanoue, Shintarou; Yasukochi, Yuji; Touhara, Kazushige; Nishioka, Takaaki

2004-01-01

Sex pheromones released by female moths are detected with high specificity and sensitivity in the olfactory sensilla of antennae of conspecific males. Bombykol in the silkmoth Bombyx mori was the first sex pheromone to be identified. Here we identify a male-specific G protein-coupled olfactory receptor gene, B. mori olfactory receptor 1 (BmOR-1), that appears to encode a bombykol receptor. The BmOR-1 gene is located on the Z sex chromosome, has an eight-exon/seven-intron structure, and exhibits male-specific expression in the pheromone receptor neurons of male moth antenna during late pupal and adult stages. Bombykol stimulation of Xenopus laevis oocytes expressing BmOR-1 and BmGαq elicited robust dose-dependent inward currents on two-electrode voltage clamp recordings, demonstrating that the binding of bombykol to BmOR-1 leads to the activation of a BmGαq-mediated signaling cascade. Antennae of female moths infected with BmOR-1-recombinant baculovirus showed electrophysiological responses to bombykol but not to bombykal. These results provide evidence that BmOR-1 is a G protein-coupled sex pheromone receptor that recognizes bombykol. PMID:15545611

Bm65 is essential for the propagation of Bombyx mori nucleopolyhedrovirus.

Science.gov (United States)

Tang, Qi; Li, Guohui; Yao, Qin; Chen, Liang; Feng, Fan; Yuan, Yi; Chen, Keping

2013-01-01

Orf65 (Bm65) of Bombyx mori nucleopolyhedrovirus (BmNPV) is a highly conserved gene that encodes an unknown 104-amino acid protein. In the present study, we have shown the role of Bm65 in the baculovirus life cycle. 5'-RACE analysis showed that the transcription start site of Bm65 was 14 nucleotides upstream of the start codon ATG. The transcription profile of Bm65 was detected from 6 to 72 h postinfection (p. i.) by RT-PCR. A Bm65-knockout bacmid was constructed by homologous recombination to characterize the role of Bm65 in viral life cycle. Fluorescence microscopy showed that Bm65-knockout virus was unable to generate infectious budded virus in BmN cells. Furthermore, quantitative real-time PCR analysis demonstrated that Bm65 deletion did not affect the viral DNA replication. To conclude, Bm65 is essential for the propagation of BmNPV, but is unnecessary for the replication of viral DNA.

Production of Curcumin-Loaded Silk Fibroin Nanoparticles for Cancer Therapy

Science.gov (United States)

Coburn, Jeannine M.; Cenis, José L.; Víllora, Gloria; Kaplan, David L.

2018-01-01

Curcumin, extracted from the rhizome of Curcuma longa, has been widely used in medicine for centuries due to its anti-inflammatory, anti-cancer, anti-oxidant and anti-microbial effects. However, its bioavailability during treatments is poor because of its low solubility in water, slow dissolution rate and rapid intestinal metabolism. For these reasons, improving the therapeutic efficiency of curcumin using nanocarriers (e.g., biopolymer nanoparticles) has been a research focus, to foster delivery of the curcumin inside cells due to their small size and large surface area. Silk fibroin from the Bombyx mori silkworm is a biopolymer characterized by its biocompatibility, biodegradability, amphiphilic chemistry, and excellent mechanical properties in various material formats. These features make silk fibroin nanoparticles useful vehicles for delivering therapeutic drugs, such as curcumin. Curcumin-loaded silk fibroin nanoparticles were synthesized using two procedures (physical adsorption and coprecipitation) more scalable than methods previously described using ionic liquids. The results showed that nanoparticle formulations were 155 to 170 nm in diameter with a zeta potential of approximately −45 mV. The curcumin-loaded silk fibroin nanoparticles obtained by both processing methods were cytotoxic to carcinogenic cells, while not decreasing viability of healthy cells. In the case of tumor cells, curcumin-loaded silk fibroin nanoparticles presented higher efficacy in cytotoxicity against neuroblastoma cells than hepatocarcinoma cells. In conclusion, curcumin-loaded silk fibroin nanoparticles constitute a biodegradable and biocompatible delivery system with the potential to treat tumors by local, long-term sustained drug delivery. PMID:29495296

An L319F mutation in transmembrane region 3 (TM3) selectively reduces sensitivity to okaramine B of the Bombyx mori l-glutamate-gated chloride channel.

Science.gov (United States)

Furutani, Shogo; Okuhara, Daiki; Hashimoto, Anju; Ihara, Makoto; Kai, Kenji; Hayashi, Hideo; Sattelle, David B; Matsuda, Kazuhiko

2017-10-01

Okaramines produced by Penicillium simplicissimum AK-40 activate l-glutamate-gated chloride channels (GluCls) and thus paralyze insects. However, the okaramine binding site on insect GluCls is poorly understood. Sequence alignment shows that the equivalent of residue Leucine319 of the okaramine B sensitive Bombyx mori (B. mori) GluCl is a phenylalanine in the okaramine B insensitive B. mori γ-aminobutyric acid-gated chloride channel of the same species. This residue is located in the third transmembrane (TM3) region, a location which in a nematode GluCl is close to the ivermectin binding site. The B. mori GluCl containing the L319F mutation retained its sensitivity to l-glutamate, but responses to ivermectin were reduced and those to okaramine B were completely blocked.

Genome Sequence of Enterococcus mundtii EM01, Isolated from Bombyx mori Midgut and Responsible for Flacherie Disease in Silkworms Reared on an Artificial Diet

DEFF Research Database (Denmark)

de Diego-Diaz, Beatriz; Treu, Laura; Campanaro, Stefano

2018-01-01

The whole genome sequence of Enterococcus mundtii strain EM01 is reported here. The isolate proved to be the cause of flacherie in Bombyx mori To date, the genomes of 11 other E. mundtii strains have been sequenced. EM01 is the only strain that displayed active pathological effects on its...

Radiation degradation of silk protein

International Nuclear Information System (INIS)

Pewlong, W.; Sudatis, B.; Takeshita, Hidefumi; Yoshii, Fumio; Kume, Tamikazu

2000-01-01

Silk fibroin fiber from the domesticated silkworm Bombyx mori was irradiated using an electron beam accelerator to investigate the application of the radiation degradation technique as a means to solubilize fibroin. The irradiation caused a significant degradation of the fiber. The tensile strength of fibroin fiber irradiated up to 2500 kGy decreased rapidly with increasing dose. The presence of oxygen in the irradiation atmosphere enhanced degradation of the tensile strength. The solubilization of irradiated fibroin fiber was evaluated using the following three kinds of solutions: a calcium chloride solution(CaCl 2 /C 2 H 5 OH/H 2 O=1:2:8 in mole ratio), a hydrochloric acid (0.5 N) and a distilled water. Dissolution of fibroin fiber into these solutions was significantly enhanced by irradiation. Especially, an appreciable amount of water soluble proteins was extracted by a distilled water. (author)

Radiation degradation of silk protein

Energy Technology Data Exchange (ETDEWEB)

Pewlong, W; Sudatis, B [Office of Atomic Energy for Peace, Bangkok (Thailand); Takeshita, Hidefumi; Yoshii, Fumio; Kume, Tamikazu [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment

2000-03-01

Silk fibroin fiber from the domesticated silkworm Bombyx mori was irradiated using an electron beam accelerator to investigate the application of the radiation degradation technique as a means to solubilize fibroin. The irradiation caused a significant degradation of the fiber. The tensile strength of fibroin fiber irradiated up to 2500 kGy decreased rapidly with increasing dose. The presence of oxygen in the irradiation atmosphere enhanced degradation of the tensile strength. The solubilization of irradiated fibroin fiber was evaluated using the following three kinds of solutions: a calcium chloride solution(CaCl{sub 2}/C{sub 2}H{sub 5}OH/H{sub 2}O=1:2:8 in mole ratio), a hydrochloric acid (0.5 N) and a distilled water. Dissolution of fibroin fiber into these solutions was significantly enhanced by irradiation. Especially, an appreciable amount of water soluble proteins was extracted by a distilled water. (author)

Effect of gamma-rays on some technologic properties of cocoon and filament of the silk worm (Bombyx mori L.)

International Nuclear Information System (INIS)

Binkh, T.T.; Petkov, N.; Malinova, K.

1993-01-01

The effect of irradiation of silk worm eggs with 1.00, 2.00, 3.00, 4.00, 5.00, 6.00 and 7.00 Gy gamma-rays on some major technologic properties of cocoons and filament of the mulbery silk worm was studied. Single irradiation of silk worm during the phase of highest lengthening of nucleus development causes both stimulating and inhibitory effect on the technologic properties of the cocoons and the filament. The degree of stimulation or inhibition is dependent on the irradiation dose, the specificity of technologic processes and biologic characteristics of silk worm species and hybrids. Gamma-irradiation with doses 2.00 and 3.00 Gy stimulates the increase in weight of silk covering by 2.07-8.28%, raw cocoon silkness by 0.38-3.21 points and length of cocoon filament by 40-151 m. Irradiation of silk worm eggs with 2.00-4.00 Gy gamma-rays decreases by 1.4-2.3 kg (12.61-21.91%) the quantity of raw cocoons, required for production of 1 kg grege. 9 refs., 4 tabs. (author)

Molecular cloning of a functional allatostatin gut/brain receptor and an allatostatin preprohormone from the silkworm Bombyx mori

DEFF Research Database (Denmark)

Secher, Thomas; Lenz, C; Cazzamali, G

2001-01-01

in the DAR-1 and DAR-2 genes, showing that the three receptors are not only structurally but also evolutionarily related. Furthermore, we have cloned a Bombyx allatostatin preprohormone that contains eight different A-type allatostatins. Chinese hamster ovary cells permanently transfected with BAR DNA react......The cockroach-type or A-type allatostatins are inhibitory insect neuropeptides with the C-terminal sequence Tyr/Phe-X-Phe-Gly-Leu-NH(2). Here, we have cloned an A-type allatostatin receptor from the silkworm Bombyx mori (BAR). BAR is 361 amino acid residues long, has seven transmembrane domains....... Northern blots and quantitative reverse transcriptase-polymerase chain reaction of different larval tissues show that BAR mRNA is mainly expressed in the gut and to a much lesser extent in the brain. To our knowledge, this is the first report on the molecular cloning and functional expression of an insect...

The Bombyx mori nucleopolyhedrovirus (BmNPV) ODV-E56 envelope protein is also a per os infectivity factor.

Science.gov (United States)

Xiang, Xingwei; Chen, Lin; Guo, Aiqin; Yu, Shaofang; Yang, Rui; Wu, Xiaofeng

2011-01-01

The Bombyx mori nucleopolyhedrovirus (BmNPV) odv-e56 gene is a late gene and encodes an occlusion-derived virus (ODV)-specific envelope protein, ODV-E56. To determine its role in the BmNPV life cycle, an odv-e56 null virus, BmE56D, was constructed through homologous recombination. A repaired virus was also constructed, named BmE56DR. The production of budded virion (BV) and polyhedra, the replication of viral DNA, and the morphological of infected BmN cells were analyzed, revealing no significant difference among the BmE56D, the wild-type (WT), and the BmE56DR virus. Larval bioassays demonstrated that injection of BmE56D BV into the hemocoel could kill B. mori larvae as efficiently as repaired and WT viruses, however BmE56D was unable to infect the B. mori larvae when inoculated per os. Thus, these results indicated that ODV-E56 envelope protein of BmNPV is also a per os infectivity factor (PIF), but is not essential for virus replication. Copyright © 2010 Elsevier B.V. All rights reserved.

Morus planting and silk production in Oxus civilization (2000 BC), Transoxiana

Science.gov (United States)

Zhou, X.; Li, X.; Wang, J.

2017-12-01

Silk is the most important luxury in ancient trade, which promoted communications between east and west civilizations that facilitated the development of them. Currently, probably more than 99% of the silk in commerce in the world today comes from a single species called the silkworm or mulberry silk moth, Bombyx mori (L.), of the family Bombycidae. At present, a list of occurrences of unearthed early silk thread, textile and terracotta figures of China suggests that wild silk has been widely used for weave in Yangtze river and Yellow River basin at least 5000 cal yr BP. On the other hand, the earliest silk fabric out China is from the earliest civilization Harappa site (4500-4000 cal a BP) that confirmed the early use of wild silkworms in South Asia.. In addition, in the Egyptian Deir al Medina relics site, the unearthed silk also as old as nearly 3000 cal a BP, and a serials of pre-han silk also unearthed 3000-2500 cal a BP in Europe. But, the appearance of these out-China silk is usually considered to be the result of the early trade or wild silkmoth products. Here we present a synthesis study of chronology, entomology, protein group, the paleoethnobotany form three Bronze Age site (Sapalli, Jarzgudan, Molleli) concerning on the paleo environment, agriculture gardening, and the possible mulberry silkworm utilization in Bronze Age Tensoxiana 4000 cal a BP. Together with archaeobotany and chronology data from Xinjiang, Hexi corridor and the Loess Plateau in China, we analysis the status of the mulberry silk factory in Bronze Age in Transoxiana and it possible connection to ancient China.

Transparent and flexible resistive switching memory devices with a very high ON/OFF ratio using gold nanoparticles embedded in a silk protein matrix

Science.gov (United States)

Gogurla, Narendar; Mondal, Suvra P.; Sinha, Arun K.; Katiyar, Ajit K.; Banerjee, Writam; Kundu, Subhas C.; Ray, Samit K.

2013-08-01

The growing demand for biomaterials for electrical and optical devices is motivated by the need to make building blocks for the next generation of printable bio-electronic devices. In this study, transparent and flexible resistive memory devices with a very high ON/OFF ratio incorporating gold nanoparticles into the Bombyx mori silk protein fibroin biopolymer are demonstrated. The novel electronic memory effect is based on filamentary switching, which leads to the occurrence of bistable states with an ON/OFF ratio larger than six orders of magnitude. The mechanism of this process is attributed to the formation of conductive filaments through silk fibroin and gold nanoparticles in the nanocomposite. The proposed hybrid bio-inorganic devices show promise for use in future flexible and transparent nanoelectronic systems.

Transparent and flexible resistive switching memory devices with a very high ON/OFF ratio using gold nanoparticles embedded in a silk protein matrix

International Nuclear Information System (INIS)

Gogurla, Narendar; Mondal, Suvra P; Sinha, Arun K; Katiyar, Ajit K; Banerjee, Writam; Ray, Samit K; Kundu, Subhas C

2013-01-01

The growing demand for biomaterials for electrical and optical devices is motivated by the need to make building blocks for the next generation of printable bio-electronic devices. In this study, transparent and flexible resistive memory devices with a very high ON/OFF ratio incorporating gold nanoparticles into the Bombyx mori silk protein fibroin biopolymer are demonstrated. The novel electronic memory effect is based on filamentary switching, which leads to the occurrence of bistable states with an ON/OFF ratio larger than six orders of magnitude. The mechanism of this process is attributed to the formation of conductive filaments through silk fibroin and gold nanoparticles in the nanocomposite. The proposed hybrid bio-inorganic devices show promise for use in future flexible and transparent nanoelectronic systems. (paper)

Inter- and intra-population genetic variability of introduced silkworm (Bombyx mori L. strains raised in Bulgaria

Directory of Open Access Journals (Sweden)

Teodora Staykova

2013-01-01

Full Text Available The genetic variability of four populations belonging to two introduced silkworm strains (Bombyx mori L. of various origins has been studied using isoenzymic analysis of six enzyme systems. Nonspecific esterases, phosphoglucomutase, malate dehydrogenase, acid phosphatase, alkaline phosphatase and hexokinase from different tissue of larvae 5th instar have been analysed using PAGE. Polymorphism in six from a total of nine loci has been found. Inter- and intra-population differences have been ascertained expressed in different allele composition of the gene pool and different frequencies of alleles. A higher degree of inter-population variability has been reported on the acid phosphatase and a lower one – on the phosphoglucomutase.

The dipteran parasitoid Exorista bombycis induces pro- and anti-oxidative reactions in the silkworm Bombyx mori: Enzymatic and genetic analysis.

Science.gov (United States)

Makwana, Pooja; Pradeep, Appukuttan Nair R; Hungund, Shambhavi P; Ponnuvel, Kangayam M; Trivedy, Kanika

2017-02-01

Hymenopteran parasitoids inject various factors including polydnaviruses along with their eggs into their host insects that suppress host immunity reactions to the eggs and larvae. Less is known about the mechanisms evolved in dipteran parasitoids that suppress host immunity. Here we report that the dipteran, Exorista bombycis, parasitization leads to pro-oxidative reactions and activation of anti-oxidative enzymes in the silkworm Bombyx mori larva. We recorded increased activity of oxidase, superoxide dismutase, thioredoxin peroxidase, catalase, glutathione-S-transferase (GST), and peroxidases in the hemolymph plasma, hemocytes, and fat body collected from B. mori after E. bombycis parasitization. Microarray and qPCR showed differential expression of genes encoding pro- and anti-oxidant enzymes in the hemocytes. The significance of this work lies in increased understanding of dipteran parasitoid biology. © 2017 Wiley Periodicals, Inc.

Vertebrate estrogen regulates the development of female characteristics in silkworm, Bombyx mori.

Science.gov (United States)

Shen, Guanwang; Lin, Ying; Yang, Congwen; Xing, Runmiao; Zhang, Haiyan; Chen, Enxiang; Han, Chaoshan; Liu, Hongling; Zhang, Weiwei; Xia, Qingyou

2015-01-01

The vertebrate estrogens include 17-β-estradiol (E2), which has an analog in silkworm ovaries. In this study, the Bombyx mori vitellogenin gene (BmVg) was used as a biomarker to analyze the function of the E2 in silkworm. In most oviparous animals, Vg has female-specific expression. However, BmVg expression was also detected in B. mori males. Stage specific fluctuation of BmVg expression was similar in males and females, but expression levels in males were lower than in females. E2 treatment by injection or feeding of male larvae in the final instar stage induced and stimulated male BmVg transcription and protein synthesis. When silkworm ovary primordia were transplanted into males, BmVg was induced in male fat bodies. Transplanted ovaries primordia were also able to develop into ovaries and produce mature eggs. When females were treated with E2 promoted BmVg/BmVn protein accumulation in hemolymph, ovaries and eggs. However, BmVg transcription was decreased in female fat bodies. An E2 analog was identified in the hemolymph of day 3 wandering silkworms using high-performance liquid chromatography. Estradiol titers from fifth late-instar larvae to pupal stage were determined by enzyme-linked immunosorbent assay. The results suggested that silkworms synthesized a vertebrate E2 analog. This study found that E2 promoted the synthesis of BmVg, a female typical protein in silkworms. Copyright © 2014 Elsevier Inc. All rights reserved.

V-ATPase Is Involved in Silkworm Defense Response against Bombyx mori Nucleopolyhedrovirus.

Directory of Open Access Journals (Sweden)

Peng Lü

Full Text Available Silkworms are usually susceptible to the infection of Bombyx mori (B. mori nucleopolyhedrovirus (BmNPV, which can cause significant economic loss. However, some silkworm strains are identified to be highly resistant to BmNPV. To explore the silkworm genes involved in this resistance in the present study, we performed comparative real-time PCR, ATPase assay, over-expression and sub-cellular localization experiments. We found that when inoculated with BmNPV both the expression and activity of V-ATPase were significantly up-regulated in the midgut column cells (not the goblet cells of BmNPV-resistant strains (NB and BC8, the main sites for the first step of BmNPV invasion, but not in those of a BmNPV-susceptible strain 306. Furthermore, this up-regulation mainly took place during the first 24 hours post inoculation (hpi, the essential period required for establishment of virus infection, and then was down-regulated to normal levels. Amazingly, transient over-expression of V-ATPase c subunit in BmNPV-infected silkworm cells could significantly inhibit BmNPV proliferation. To our knowledge this is the first report demonstrating clearly that V-ATPase is indeed involved in the defense response against BmNPV. Our data further suggests that prompt and potent regulation of V-ATPase may be essential for execution of this response, which may enable fast acidification of endosomes and/or lysosomes to render them competent for degradation of invading viruses.

Novel silk fibroin films prepared by formic acid/hydroxyapatite dissolution method

International Nuclear Information System (INIS)

Ming, Jinfa; Liu, Zhi; Bie, Shiyu; Zhang, Feng; Zuo, Baoqi

2014-01-01

Bombyx mori silk fibroin from the silkworm was firstly found to be soluble in formic acid/hydroxyapatite system. The rheological behavior of silk fibroin solution was significantly influenced by HAp contents in dissolved solution. At the same time, silk fibroin nanofibers were observed in dissolved solution with 103.6 ± 20.4 nm in diameter. Moreover, the structure behavior of SF films prepared by formic acid/hydroxyapatite dissolution method was examined. The secondary structure of silk fibroin films was attributed to silk II structure (β-sheet), indicating that the hydroxyapatite contents in dissolved solution were not significantly affected by the structure of silk fibroin. The X-ray diffraction results exhibited obviously hydroxyapatite crystalline nature existing in silk fibroin films; however, when the hydroxyapatite content was 5.0 wt.% in dissolved solution, some hydroxyapatite crystals were converted to calcium hydrogen phosphate dehydrate in silk fibroin dissolution process. This result was also confirmed by Fourier transform infrared analysis and DSC measurement. In addition, silk fibroin films prepared by this dissolution method had higher breaking strength and extension at break. Based on these analyses, an understanding of novel SF dissolution method may provide an additional tool for designing and synthesizing advanced materials with more complex structures, which should be helpful in different fields, including biomaterial applications. - Highlights: • SF fibers were firstly successfully dissolved in FA/HAp solution. • The rheological behavior of SF solution was significantly influenced by HAp contents. • SF nanofibrils were observed in FA/HAp solution with 103.6 ± 20.4 nm in diameter. • SF films prepared by FA/HAp dissolution method had higher mechanical properties

Novel silk fibroin films prepared by formic acid/hydroxyapatite dissolution method

Energy Technology Data Exchange (ETDEWEB)

Ming, Jinfa, E-mail: jinfa.ming@gmail.com [National Engineering Laboratory for Modern Silk, Soochow University, Suzhou 215123 (China); College of Textile and Clothing Engineering, Soochow University, Suzhou 215021 (China); Liu, Zhi; Bie, Shiyu [National Engineering Laboratory for Modern Silk, Soochow University, Suzhou 215123 (China); College of Textile and Clothing Engineering, Soochow University, Suzhou 215021 (China); Zhang, Feng [Jiangsu Province Key Laboratory of Stem Cell Research, Medical College, Soochow University, Suzhou 215006 (China); Zuo, Baoqi, E-mail: bqzuo@suda.edu.cn [National Engineering Laboratory for Modern Silk, Soochow University, Suzhou 215123 (China); College of Textile and Clothing Engineering, Soochow University, Suzhou 215021 (China)

2014-04-01

Bombyx mori silk fibroin from the silkworm was firstly found to be soluble in formic acid/hydroxyapatite system. The rheological behavior of silk fibroin solution was significantly influenced by HAp contents in dissolved solution. At the same time, silk fibroin nanofibers were observed in dissolved solution with 103.6 ± 20.4 nm in diameter. Moreover, the structure behavior of SF films prepared by formic acid/hydroxyapatite dissolution method was examined. The secondary structure of silk fibroin films was attributed to silk II structure (β-sheet), indicating that the hydroxyapatite contents in dissolved solution were not significantly affected by the structure of silk fibroin. The X-ray diffraction results exhibited obviously hydroxyapatite crystalline nature existing in silk fibroin films; however, when the hydroxyapatite content was 5.0 wt.% in dissolved solution, some hydroxyapatite crystals were converted to calcium hydrogen phosphate dehydrate in silk fibroin dissolution process. This result was also confirmed by Fourier transform infrared analysis and DSC measurement. In addition, silk fibroin films prepared by this dissolution method had higher breaking strength and extension at break. Based on these analyses, an understanding of novel SF dissolution method may provide an additional tool for designing and synthesizing advanced materials with more complex structures, which should be helpful in different fields, including biomaterial applications. - Highlights: • SF fibers were firstly successfully dissolved in FA/HAp solution. • The rheological behavior of SF solution was significantly influenced by HAp contents. • SF nanofibrils were observed in FA/HAp solution with 103.6 ± 20.4 nm in diameter. • SF films prepared by FA/HAp dissolution method had higher mechanical properties.

Preparation and characterization of silk fibroin as a biomaterial with potential for drug delivery

Directory of Open Access Journals (Sweden)

Zhang Hao

2012-06-01

Full Text Available Abstract Background Degummed silk fibroin from Bombyx mori (silkworm has potential carrier capabilities for drug delivery in humans; however, the processing methods have yet to be comparatively analyzed to determine the differential effects on the silk protein properties, including crystalline structure and activity. Methods In this study, we treated degummed silk with four kinds of calcium-alcohol solutions, and performed secondary structure measurements and enzyme activity test to distinguish the differences between the regenerated fibroins and degummed silk fibroin. Results Gel electrophoresis analysis revealed that Ca(NO32-methanol, Ca(NO32-ethanol, or CaCl2-methanol treatments produced more lower molecular weights of silk fibroin than CaCl2-ethanol. X-ray diffraction and Fourier-transform infrared spectroscopy showed that CaCl2-ethanol produced a crystalline structure with more silk I (α-form, type II β-turn, while the other treatments produced more silk II (β-form, anti-parallel β-pleated sheet. Solid-State 13C cross polarization and magic angle spinning-nuclear magnetic resonance measurements suggested that regenerated fibroins from CaCl2-ethanol were nearly identical to degummed silk fibroin, while the other treatments produced fibroins with significantly different chemical shifts. Finally, enzyme activity test indicated that silk fibroins from CaCl2-ethanol had higher activity when linked to a known chemotherapeutic drug, L-asparaginase, than the fibroins from other treatments. Conclusions Collectively, these results suggest that the CaCl2-ethanol processing method produces silk fibroin with biomaterial properties that are appropriate for drug delivery.

Molecular cloning and characterization of a short peptidoglycan recognition protein from silkworm Bombyx mori.

Science.gov (United States)

Yang, P-J; Zhan, M-Y; Ye, C; Yu, X-Q; Rao, X-J

2017-12-01

Peptidoglycan is the major bacterial component recognized by the insect immune system. Peptidoglycan recognition proteins (PGRPs) are a family of pattern-recognition receptors that recognize peptidoglycans and modulate innate immune responses. Some PGRPs retain N-acetylmuramoyl-L-alanine amidase (Enzyme Commission number: 3.5.1.28) activity to hydrolyse bacterial peptidoglycans. Others have lost the enzymatic activity and work only as immune receptors. They are all important modulators for innate immunity. Here, we report the cloning and functional analysis of PGRP-S4, a short-form PGRP from the domesticated silkworm, Bombyx mori. The PGRP-S4 gene encodes a protein of 199 amino acids with a signal peptide and a PGRP domain. PGRP-S4 was expressed in the fat body, haemocytes and midgut. Its expression level was significantly induced by bacterial challenges in the midgut. The recombinant PGRP-S4 bound bacteria and different peptidoglycans. In addition, it inhibited bacterial growth and hydrolysed an Escherichia coli peptidoglycan in the presence of Zn 2+ . Scanning electron microscopy showed that PGRP-S4 disrupted the bacterial cell surface. PGRP-S4 further increased prophenoloxidase activation caused by peptidoglycans. Taken together, our data suggest that B. mori PGRP-S4 has multiple functions in immunity. © 2017 The Royal Entomological Society.

Cell Cycle-Dependent Recruitment of Polycomb Proteins to the ASNS Promoter Counteracts C/ebp-Mediated Transcriptional Activation in Bombyx mori

Science.gov (United States)

Li, Zhiqing; Cheng, Daojun; Mon, Hiroaki; Zhu, Li; Xu, Jian; Tatsuke, Tsuneyuki; Lee, Jae Man; Xia, Qingyou; Kusakabe, Takahiro

2013-01-01

Epigenetic modifiers and transcription factors contribute to developmentally programmed gene expression. Here, we establish a functional link between epigenetic regulation by Polycomb group (PcG) proteins and transcriptional regulation by C/ebp that orchestrates the correct expression of Bombyx mori asparagine synthetase (BmASNS), a gene involved in the biosynthesis of asparagine. We show that the cis-regulatory elements of YY1-binding motifs and the CpG island present on the BmASNS promoter are required for the recruitment of PcG proteins and the subsequent deposition of the epigenetic repression mark H3K27me3. RNAi-mediated knockdown of PcG genes leads to derepression of the BmASNS gene via the recruitment of activators, including BmC/ebp, to the promoter. Intriguingly, we find that PcG proteins and BmC/ebp can dynamically modulate the transcriptional output of the BmASNS target in a cell cycle-dependent manner. It will be essential to suppress BmASNS expression by PcG proteins at the G2/M phase of the cell cycle in the presence of BmC/ebp activator. Thus, our results provide a novel insight into the molecular mechanism underlying the recruitment and regulation of the PcG system at a discrete gene locus in Bombyx mori. PMID:23382816

Study on the effect of gamma-radiation on the development of silk worm (Bombyx mori L.)

International Nuclear Information System (INIS)

Grekov, D.

1995-01-01

These investigations are of special interest to the breeding practice considering the lack of profound research activity. The main purpose was to find out possibilities of using gamma-rays as a mutagenic factor in sericulture. The results obtained show that the irradiation of silk worm eggs at b 2 stage of embryo development with 5 Gy stimulates the biological development. The irradiation doses of 10-25 Gy inhibit mulberry silk worm development. The different species react in different way. Probably mutation forms are to be sought within 10-25 Gy doses. 10 refs., 3 tabs. (author)

Silk scaffolds connected with different naturally occurring biomaterials for prostate cancer cell cultivation in 3D.

Science.gov (United States)

Bäcker, Anne; Erhardt, Olga; Wietbrock, Lukas; Schel, Natalia; Göppert, Bettina; Dirschka, Marian; Abaffy, Paul; Sollich, Thomas; Cecilia, Angelica; Gruhl, Friederike J

2017-02-01

In the present work, different biopolymer blend scaffolds based on the silk protein fibroin from Bombyx mori (BM) were prepared via freeze-drying method. The chemical, structural, and mechanical properties of the three dimensional (3D) porous silk fibroin (SF) composite scaffolds of gelatin, collagen, and chitosan as well as SF from Antheraea pernyi (AP) and the recombinant spider silk protein spidroin (SSP1) have been systematically investigated, followed by cell culture experiments with epithelial prostate cancer cells (LNCaP) up to 14 days. Compared to the pure SF scaffold of BM, the blend scaffolds differ in porous morphology, elasticity, swelling behavior, and biochemical composition. The new composite scaffold with SSP1 showed an increased swelling degree and soft tissue like elastic properties. Whereas, in vitro cultivation of LNCaP cells demonstrated an increased growth behavior and spheroid formation within chitosan blended scaffolds based on its remarkable porosity, which supports nutrient supply matrix. Results of this study suggest that silk fibroin matrices are sufficient and certain SF composite scaffolds even improve 3D cell cultivation for prostate cancer research compared to matrices based on pure biomaterials or synthetic polymers. © 2016 Wiley Periodicals, Inc.

Cloning, expression and characterization of alcohol dehydrogenases in the silkworm Bombyx mori

Directory of Open Access Journals (Sweden)

Nan Wang

2011-01-01

Full Text Available Alcohol dehydrogenases (ADH are a class of enzymes that catalyze the reversible oxidation of alcohols to corresponding aldehydes or ketones, by using either nicotinamide adenine dinucleotide (NAD or nicotinamide adenine dinucleotide phosphate (NADP, as coenzymes. In this study, a short-chain ADH gene was identified in Bombyx mori by 5'-RACE PCR. This is the first time the coding region of BmADH has been cloned, expressed, purified and then characterized. The cDNA fragment encoding the BmADH protein was amplified from a pool of silkworm cDNAs by PCR, and then cloned into E. coli expression vector pET-30a(+. The recombinant His-tagged BmADH protein was expressed in E. coli BL21 (DE3, and then purified by metal chelating affinity chromatography. The soluble recombinant BmADH, produced at low-growth temperature, was instrumental in catalyzing the ethanol-dependent reduction of NAD+, thereby indicating ethanol as one of the substrates of BmADH.

A discovery of novel microRNAs in the silkworm (Bombyx mori) genome.

Science.gov (United States)

Yu, Xiaomin; Zhou, Qing; Cai, Yimei; Luo, Qibin; Lin, Hongbin; Hu, Songnian; Yu, Jun

2009-12-01

MicroRNAs (miRNAs) are pivotal regulators involved in various physiological and pathological processes via their post-transcriptional regulation of gene expressions. We sequenced 14 libraries of small RNAs constructed from samples spanning the life cycle of silkworms, and discovered 50 novel miRNAs previously not known in animals and verified 43 of them using stem-loop RT-PCR. Our genome-wide analyses of 27 species-specific miRNAs suggest they arise from transposable elements, protein-coding genes duplication/transposition and random foldback sequences; which is consistent with the idea that novel animal miRNAs may evolve from incomplete self-complementary transcripts and become fixed in the process of co-adaptation with their targets. Computational prediction suggests that the silkworm-specific miRNAs may have a preference of regulating genes that are related to life-cycle-associated traits, and these genes can serve as potential targets for subsequent studies of the modulating networks in the development of Bombyx mori.

Production of Curcumin-Loaded Silk Fibroin Nanoparticles for Cancer Therapy

Directory of Open Access Journals (Sweden)

Mercedes G. Montalbán

2018-02-01

Full Text Available Curcumin, extracted from the rhizome of Curcuma longa, has been widely used in medicine for centuries due to its anti-inflammatory, anti-cancer, anti-oxidant and anti-microbial effects. However, its bioavailability during treatments is poor because of its low solubility in water, slow dissolution rate and rapid intestinal metabolism. For these reasons, improving the therapeutic efficiency of curcumin using nanocarriers (e.g., biopolymer nanoparticles has been a research focus, to foster delivery of the curcumin inside cells due to their small size and large surface area. Silk fibroin from the Bombyx mori silkworm is a biopolymer characterized by its biocompatibility, biodegradability, amphiphilic chemistry, and excellent mechanical properties in various material formats. These features make silk fibroin nanoparticles useful vehicles for delivering therapeutic drugs, such as curcumin. Curcumin-loaded silk fibroin nanoparticles were synthesized using two procedures (physical adsorption and coprecipitation more scalable than methods previously described using ionic liquids. The results showed that nanoparticle formulations were 155 to 170 nm in diameter with a zeta potential of approximately −45 mV. The curcumin-loaded silk fibroin nanoparticles obtained by both processing methods were cytotoxic to carcinogenic cells, while not decreasing viability of healthy cells. In the case of tumor cells, curcumin-loaded silk fibroin nanoparticles presented higher efficacy in cytotoxicity against neuroblastoma cells than hepatocarcinoma cells. In conclusion, curcumin-loaded silk fibroin nanoparticles constitute a biodegradable and biocompatible delivery system with the potential to treat tumors by local, long-term sustained drug delivery.

Serial analysis of gene expression in the silkworm, Bombyx mori.

Science.gov (United States)

Huang, Jianhua; Miao, Xuexia; Jin, Weirong; Couble, Pierre; Mita, Kasuei; Zhang, Yong; Liu, Wenbin; Zhuang, Leijun; Shen, Yan; Keime, Celine; Gandrillon, Olivier; Brouilly, Patrick; Briolay, Jerome; Zhao, Guoping; Huang, Yongping

2005-08-01

The silkworm Bombyx mori is one of the most economically important insects and serves as a model for Lepidoptera insects. We used serial analysis of gene expression (SAGE) to derive profiles of expressed genes during the developmental life cycle of the silkworm and to create a reference for understanding silkworm metamorphosis. We generated four SAGE libraries, one from each of the four developmental stages of the silkworm. In total we obtained 257,964 SAGE tags, of which 39,485 were unique tags. Sorted by copy number, 14.1% of the unique tags were detected at a median to high level (five or more copies), 24.2% at lower levels (two to four copies), and 61.7% as single copies. Using a basic local alignment search tool on the EST database, 35% of the tags matched known silkworm expressed sequence tags. SAGE demonstrated that a number of the genes were up- or down-regulated during the four developmental phases of the egg, larva, pupa, and adult. Furthermore, we found that the generation of longer cDNA fragments from SAGE tags constituted the most efficient method of gene identification, which facilitated the analysis of a large number of unknown genes.

Development of novel electrospun nanofibrous scaffold from P. ricini and A. mylitta silk fibroin blend with improved surface and biological properties

International Nuclear Information System (INIS)

Panda, N.; Bissoyi, A.; Pramanik, K.; Biswas, A.

2015-01-01

Biomaterials that stimulate cell attachment and proliferation without any surface modification (e.g. RGD coating) provide potent and cost effective scaffold for regenerative medicine. This study assessed the physico-chemical properties and cell supportive potential of a silk fibroin blend scaffold derived from eri (Philosamia ricini) and tasar (Antheraea mylitta) silk (ET) respectively by electrospinning process. The scanning electron microscopy and transmission electron microscopy study found that the fiber diameters are in 200 to 800 nm range with flat morphology. The porosity of ET scaffold is found to be 79 ± 5% with majority of pore diameter between 2.5 to 5 nm. Similarly, Bombyx mori (BM) silk fibroin and gelatin nanofibrous scaffolds were prepared and taken as control. The ultimate tensile strength of the ET and BM scaffold are found to be 1.83 ± 0.13 MPa and 1.47 ± 0.10 MPa respectively. The measured contact angle (a measure of hydrophilicity) for ET (54.7° ± 1.8°) is found to be lower than BM (62° ± 2.3°). The ability to deposit apatite over ET is comparable to that of BM nanofibers. All the scaffolds were seeded with cord blood derived mesenchymal stem cells (hMSCs) and cultured for 14 days in vitro. The immunofluorescence study reveals enhanced cell attachment with higher metabolic activity for MSCs grown over ET than BM and gelatin. The ET scaffold also demonstrated expression of higher amount cell adhesion molecules (CD29/CD44) and higher proliferation rate than BM and gelatin as confirmed by MTT assay, DNA content estimation assay, flow cytometry study and SEM study. Overall, it may be concluded that ET scaffold may have potential in developing bone tissue grafts for clinical applications in the future. - Highlights: • We have fabricated eri–tasar blended electrospun silk fibroin nanofiber with superior surface property. • The hydrophilicity is higher than the silk fibroin nanofiber derived from Bombyx mori (BM). • The nanofibrous

Development of novel electrospun nanofibrous scaffold from P. ricini and A. mylitta silk fibroin blend with improved surface and biological properties

Energy Technology Data Exchange (ETDEWEB)

Panda, N.; Bissoyi, A.; Pramanik, K.; Biswas, A., E-mail: amitb79@gmail.com

2015-03-01

Biomaterials that stimulate cell attachment and proliferation without any surface modification (e.g. RGD coating) provide potent and cost effective scaffold for regenerative medicine. This study assessed the physico-chemical properties and cell supportive potential of a silk fibroin blend scaffold derived from eri (Philosamia ricini) and tasar (Antheraea mylitta) silk (ET) respectively by electrospinning process. The scanning electron microscopy and transmission electron microscopy study found that the fiber diameters are in 200 to 800 nm range with flat morphology. The porosity of ET scaffold is found to be 79 ± 5% with majority of pore diameter between 2.5 to 5 nm. Similarly, Bombyx mori (BM) silk fibroin and gelatin nanofibrous scaffolds were prepared and taken as control. The ultimate tensile strength of the ET and BM scaffold are found to be 1.83 ± 0.13 MPa and 1.47 ± 0.10 MPa respectively. The measured contact angle (a measure of hydrophilicity) for ET (54.7° ± 1.8°) is found to be lower than BM (62° ± 2.3°). The ability to deposit apatite over ET is comparable to that of BM nanofibers. All the scaffolds were seeded with cord blood derived mesenchymal stem cells (hMSCs) and cultured for 14 days in vitro. The immunofluorescence study reveals enhanced cell attachment with higher metabolic activity for MSCs grown over ET than BM and gelatin. The ET scaffold also demonstrated expression of higher amount cell adhesion molecules (CD29/CD44) and higher proliferation rate than BM and gelatin as confirmed by MTT assay, DNA content estimation assay, flow cytometry study and SEM study. Overall, it may be concluded that ET scaffold may have potential in developing bone tissue grafts for clinical applications in the future. - Highlights: • We have fabricated eri–tasar blended electrospun silk fibroin nanofiber with superior surface property. • The hydrophilicity is higher than the silk fibroin nanofiber derived from Bombyx mori (BM). • The nanofibrous

Oxidative stress and cytotoxicity elicited lipid peroxidation in hemocytes of Bombyx mori larva infested with dipteran parasitoid, Exorista bombycis.

Science.gov (United States)

Pooja, Makwana; Pradeep, Appukuttan Nair R; Hungund, Shambhavi P; Sagar, Chandrashekhar; Ponnuvel, Kangayam M; Awasthi, Arvind K; Trivedy, Kanika

2017-12-20

Parasitization of silkworm, Bombyx mori by invasive larva of dipteran parasitoid Exorista bombycis caused upto 20% revenue loss in sericulture. The parasitism was successful by suppressing host immune system however mechanism of immune suppression induced by E. bombycis is unknown which is unravelled here. The infestation induced cytotoxic symptoms in host hemocytes, such as vacuolated cytoplasm, porous plasma membrane, indented nuclei with condensed chromatin and dilated RER. One of the markers of necrosis is cell permeabilization, which can be measured as released lactate dehydrogenase (LDH). LDH level showed significantly (Pmori.

The effect of gamma irradiation on some morphological and quantitative changes of Bombyx mori L. silk gland; Vliyanie na gama lychite vyrhu nykoi morfologichni i kolichestveni izmeneniya na koprinenootdelitelnata zhleza na Bombyx mori L

Energy Technology Data Exchange (ETDEWEB)

Petkov, N; Malinova, K [Institute of Animal Breeding, Kostinbrod (Bulgaria); Binkh, N [National Centre of Sericulture, Hanoj (Viet Nam)

1997-12-31

A study to determine the effect of gamma irradiation of silkworm eggs at doses of 1.00; 2.00 and 3.00 on silk gland weight, length and width is performed. It was found that gamma irradiation of eggs in the stage of embryo most intensive growth in length (B{sub 2}) at doses 2.00 and 3.00 Gy stimulates increasing of silk glands weight in silkworms on the fifth day instar by 12-25 mg, as well as the silk worm width - by 7-33 {mu}m, which is of significant importance for the synthesis and secretion of silk proteins (fibroin and sericin). A breed specificity was also observed. 4 refs.

Genetic engineered color silk: fabrication of a photonics material through a bioassisted technology.

Science.gov (United States)

Shimizu, Katsuhiko

2018-05-15

Silk produced by the silkworm Bombyx mori is an attractive material because of its luster, smooth and soft texture, conspicuous mechanical strength, good biocompatibility, slow biodegradation, and carbon neutral synthesis. Silkworms have been domesticated and bred for production of better quality and quantity of silk, resulting in the development of sericulture and the textile industry. Silk is generally white, so dyeing is required to obtain colored fiber. However, the dyeing process involves harsh conditions and generates a large volume of waste water, which have environmentally and economically negative impacts. Although some strains produce cocoons that contain pigments derived from the mulberry leaves that they eat, the pigments are distributed in the sericin layer and are lost during gumming. In trials for production of colored silk by feeding silkworms on diets containing dyes, only limited species of dye molecules were incorporated into the silk threads. A method for the generation of transgenic silkworm was established in conjunction with the discovery of green fluorescent protein (GFP), and silkworms carrying the GFP gene spun silk threads that formed cocoons that glowed bright green and still retained the original properties of silk. A wide range of color variation of silk threads has been obtained by replacing the GFP gene with the genes of other fluorescent proteins chosen from the fluorescent protein palette. The genetically modified silk with photonic properties can be processed to form various products including linear threads, 2D fabrics, and 3D materials. The transgenic colored silk could be economically advantageous due to addition of a new value to silk and reduction of cost for water waste, and environmentally preferable for saving water. Here, I review the literature regarding the production methods of fluorescent silk from transgenic silkworms and present examples of genetically modified color silk.

A Baculovirus immediate-early gene, ie1, promoter drives efficient expression of a transgene in both Drosophila melanogaster and Bombyx mori.

Directory of Open Access Journals (Sweden)

Mika Masumoto

Full Text Available Many promoters have been used to drive expression of heterologous transgenes in insects. One major obstacle in the study of non-model insects is the dearth of useful promoters for analysis of gene function. Here, we investigated whether the promoter of the immediate-early gene, ie1, from the Bombyx mori nucleopolyhedrovirus (BmNPV could be used to drive efficient transgene expression in a wide variety of insects. We used a piggyBac-based vector with a 3xP3-DsRed transformation marker to generate a reporter construct; this construct was used to determine the expression patterns driven by the BmNPV ie1 promoter; we performed a detailed investigation of the promoter in transgene expression pattern in Drosophila melanogaster and in B. mori. Drosophila and Bombyx belong to different insect orders (Diptera and Lepidoptera, respectively; however, and to our surprise, ie1 promoter-driven expression was evident in several tissues (e.g., prothoracic gland, midgut, and tracheole in both insects. Furthermore, in both species, the ie1 promoter drove expression of the reporter gene from a relatively early embryonic stage, and strong ubiquitous ie1 promoter-driven expression continued throughout the larval, pupal, and adult stages by surface observation. Therefore, we suggest that the ie1 promoter can be used as an efficient expression driver in a diverse range of insect species.

Fine Mapping of a Degenerated Abdominal Legs Mutant (Edl in Silkworm, Bombyx mori.

Directory of Open Access Journals (Sweden)

Honglei Wang

Full Text Available In insects, abdominal appendages, also called prolegs, vary due to adaptive evolution. Mutations on prolegs within species provide insights to better understand the mechanisms underlying appendage development and diversity. In silkworm Bombyx mori, extra-crescents and degenerated abdominal legs (Edl mutant, belonging to the E pseudoallele group, is a spontaneous mutation that adds crescents and degenerates prolegs on the third abdominal segment (A3. This mutation may be a homeotic transformation of A3 to A2. In this study, the Edl locus was mapped within approximately a 211 Kb region that is 10 Kb upstream of Bmabdominal-A (Bmabd-A. RT-quantitative PCR (RT-qPCR and Western blot analysis of Bmabd-A expression showed a slight but significant decrease, while the expression of BmUltrabithorax (BmUbx was up-regulated in the Edl mutant compared to wildtype (Dazao. Moreover, we also found that BmDistal-less (BmDll, which regulated the development of distal proleg structures, was missing at the tips of the A3 prolegs in the Edl mutant compared to BmDll expression in normally developed prolegs in both the wildtype and mutant. Collectively, we identified approximately a 211 Kb region in the Edl locus that regulates BmUbx and Bmabd-A expression and found that changes in BmUbx and Bmabd-A expression may lead to the loss of distal proleg structures in B. mori.

Coating of Silk Fabric Using PVA/Ciprofloxacin Hcl Nanofibers for Biomedical Applications

Directory of Open Access Journals (Sweden)

Somaye Baghersad

2016-05-01

Full Text Available In recent years, fabrication of polymeric antibacterial wound dressing has gained most attention in controlling wound infections. Silk is also a member of the broad family of protein-based polmers. The silk produced by the lepidopteran insect Bombyx mori is a highly accepted material due to its long history as a very valuable textile fiber. Recently, additional applications have been developed for silk, mainly in the field of biotechnology. Regarding its importance in wound healing, silk fabric was incorporated with ciprofloxacin, as an antibiotic, on its surface coated with electro-spun PVA/ciprofloxacin nanofibers. Before coating, degumming was carried out using autoclave technique and properties of the silk fabric, before and after degumming process, was investigated by SEM, FTIR, mechanical properties and moisture absorbance measurement. The results of all analyses showed a reduction in fibers diameter, mechanical strength and moisture absorption after degumming process. Electrospinning condition was optimized and diameter of the nanofibers, with and without drug, was measured before coating. The results showed that addition of the drug increased electrical conductivity of electrospinning solution and resulted in finer nanofibers. Antibacterial test was performed using "disk diffusion method" with Escherichia coli (EC and Staphylococcus aureus (SA bacteria to compare the antibacterial properties of degummed and non-degummed silk fabrics alone and coated with nanofibers. Measurement of bacterial inhibition zone diameter showed no antibacterial activity for degummed and non-degummed silk fabrics alone. However, the sample coated with PVA/ciprofloxacin showed antibacterial activity. The antibacterial property for SA in both cases was the same, but for EC, the antibacterial activity of degummed silk fabric was more than that of non-degummed material.

Genome-Wide Analysis of Host Responses to Four Different Types of Microorganisms in Bombyx Mori (Lepidoptera: Bombycidae).

Science.gov (United States)

Cheng, Tingcai; Lin, Ping; Huang, Lulin; Wu, Yuqian; Jin, Shengkai; Liu, Chun; Xia, Qingyou

2016-01-01

Several pathogenic microorganisms have been used to investigate the genome-wide transcriptional responses of Bombyx mori to infection. However, studies have so far each focused on one microorganism, and systematic genome-wide comparison of transcriptional responses to different pathogenic microorganisms has not been undertaken. Here, we surveyed transcriptional responses of B. mori to its natural bacterial, viral, and fungal pathogens, Bacillus bombyseptieus, B. mori nucleopolyhedrovirus (BmNPV), and Beauveria bassiana, respectively, and to nonpathogenic Escherichia coli, by microarray analysis. In total, the expression of 2,436, 1,804, 1,743, and 912 B. mori genes was modulated by infection with B. bombyseptieus, BmNPV, B. bassiana, and E. coli, respectively. Notably, the expression of 620, 400, 177, or 165 of these genes was only modulated by infection with B. bombyseptieus, BmNPV, B. bassiana, or E. coli, respectively. In contrast to the expression of genes related to juvenile hormone synthesis and metabolism, that of genes encoding juvenile hormone binding proteins was microorganism-specific. Three basal metabolic pathways were modulated by infection with any of the four microorganisms, and 3, 14, 5, and 2 metabolic pathways were specifically modulated by infection with B. bombyseptieus, BmNPV, B. bassiana, and E. coli, respectively. Interestingly, BmNPV infection modulated the JAK/STAT signaling pathway, whereas both the Imd and Toll signaling pathways were modulated by infection with B. bombyseptieus, B. bassiana, or E. coli These results elucidate potential molecular mechanisms of the host response to different microorganisms, and provide a foundation for further work on host-pathogen interaction. © The Author 2016. Published by Oxford University Press on behalf of the Entomological Society of America.

A hypothetical model of crossing Bombyx mori nucleopolyhedrovirus through its host midgut physical barrier.

Directory of Open Access Journals (Sweden)

Yang Cheng

Full Text Available Bombyx mori nucleopolyhedrovirus (BmNPV is a primary pathogen of silkworm (B. mori that causes severe economic losses each year. However, the molecular mechanisms of silkworm-BmNPV interactions, especially the silkworm proteins that can interact with the virus, are still largely unknown. In this study, the total and membrane proteins of silkworm midguts were displayed using one- and two-dimensional electrophoresis. A virus overlay assay was used to detect B. mori proteins that specifically bind to BmNPV particles. Twelve proteins were located and identified using mass spectrometry, and the different expression of the corresponding genes in BmNPV susceptible and resistant silkworm strains also indicated their involvement in BmNPV infection. The 12 proteins are grouped based on their potential roles in viral infection, for example, endocytosis, intracellular transportation, and host responses. Based on these results, we hypothesize the following: I vacuolar ATP synthase catalytic subunit A and subunit B may be implicated in the process of the membrane fusion of virus and the release of the nucleocapsid into cytoplasm; II actin, enolase and phosphoglycerate kinase are cytoskeleton associated proteins and may play an important role in BmNPV intracellular transportation; III mitochondrial prohibitin complex protein 2, ganglioside-induced differentiation-associated protein, calreticulin, regucalcin-like isoform X1 and 60 kDa heat shock protein are involved in cell apoptosis regulation during BmNPV infection in larvae midguts; IV ribosomal P0 may be associated with BmNPV infection by regulating gene expression of BmNPV; V arginine kinase has a role in the antiviral activities against BmNPV. Our work should prove informative by providing multiple protein targets and a novel direction to investigate the molecular mechanisms of the interactions between silkworms and BmNPV.

A Hypothetical Model of Crossing Bombyx mori Nucleopolyhedrovirus through Its Host Midgut Physical Barrier

Science.gov (United States)

Cheng, Yang; Wang, Xue-Yang; Hu, Hao; Killiny, Nabil; Xu, Jia-Ping

2014-01-01

Bombyx mori nucleopolyhedrovirus (BmNPV) is a primary pathogen of silkworm (B. mori) that causes severe economic losses each year. However, the molecular mechanisms of silkworm-BmNPV interactions, especially the silkworm proteins that can interact with the virus, are still largely unknown. In this study, the total and membrane proteins of silkworm midguts were displayed using one- and two-dimensional electrophoresis. A virus overlay assay was used to detect B. mori proteins that specifically bind to BmNPV particles. Twelve proteins were located and identified using mass spectrometry, and the different expression of the corresponding genes in BmNPV susceptible and resistant silkworm strains also indicated their involvement in BmNPV infection. The 12 proteins are grouped based on their potential roles in viral infection, for example, endocytosis, intracellular transportation, and host responses. Based on these results, we hypothesize the following: I) vacuolar ATP synthase catalytic subunit A and subunit B may be implicated in the process of the membrane fusion of virus and the release of the nucleocapsid into cytoplasm; II) actin, enolase and phosphoglycerate kinase are cytoskeleton associated proteins and may play an important role in BmNPV intracellular transportation; III) mitochondrial prohibitin complex protein 2, ganglioside-induced differentiation-associated protein, calreticulin, regucalcin-like isoform X1 and 60 kDa heat shock protein are involved in cell apoptosis regulation during BmNPV infection in larvae midguts; IV) ribosomal P0 may be associated with BmNPV infection by regulating gene expression of BmNPV; V) arginine kinase has a role in the antiviral activities against BmNPV. Our work should prove informative by providing multiple protein targets and a novel direction to investigate the molecular mechanisms of the interactions between silkworms and BmNPV. PMID:25502928

Antiviral activity and specific modes of action of bacterial prodigiosin against Bombyx mori nucleopolyhedrovirus in vitro.

Science.gov (United States)

Zhou, Wei; Zeng, Cheng; Liu, RenHua; Chen, Jie; Li, Ru; Wang, XinYan; Bai, WenWen; Liu, XiaoYuan; Xiang, TingTing; Zhang, Lin; Wan, YongJi

2016-05-01

Prodigiosin, the tripyrrole red pigment, is a bacterial secondary metabolite with multiple bioactivities; however, the antiviral activity has not been reported yet. In the present study, we found the antiviral activity of bacterial prodigiosin on Bombyx mori nucleopolyhedrovirus (BmNPV)-infected cells in vitro, with specific modes of action. Prodigiosin at nontoxic concentrations selectively killed virus-infected cells, inhibited viral gene transcription, especially viral early gene ie-1, and prevented virus-mediated membrane fusion. Under prodigiosin treatment, both progeny virus production and viral DNA replication were significantly inhibited. Fluorescent assays showed that prodigiosin predominantly located in cytoplasm which suggested it might interact with cytoplasm factors to inhibit virus replication. In conclusion, the present study clearly indicates that prodigiosin possesses significant antiviral activity against BmNPV.

Targeted heavy-ion microbeam irradiation of the embryo but not yolk in the diapause-terminated egg of the silkworm, bombyx mori, induces the somatic mutation

International Nuclear Information System (INIS)

Furusawa, Toshiharu; Fukamoto, Kana; Sakashita, Tetsuya; Funayama, Tomoo; Kobayashi, Yasuhiko; Kakizaki, Takehiko; Wada, Seiichi; Hamada, Nobuyuki; Suzuki, Hiromi; Ishioka, Noriaki; Nagaoka, Shunji

2009-01-01

Using heavy-ion microbeam, we report target irradiation of selected compartments within the diapause-terminated egg and its mutational consequences in the silkworm, Bombyx mori. On one hand, carbon-ion exposure of embryo to 0.5-6 Gy increased the somatic mutation frequency, suggesting targeted radiation effects. On the other, such increases were not observed when yolk was targeted, suggesting a lack of nontargeted bystander effect. (author)

JAK/STAT signaling pathway-mediated immune response in silkworm (Bombyx mori) challenged by Beauveria bassiana.

Science.gov (United States)

Geng, Tao; Lv, Ding-Ding; Huang, Yu-Xia; Hou, Cheng-Xiang; Qin, Guang-Xing; Guo, Xi-Jie

2016-12-20

Innate immunity was critical in insects defensive system and able to be induced by Janus kinase/signal transducer and activator of transcription cascade transduction (JAK/STAT) signaling pathway. Currently, it had been identified many JAK/STAT signaling pathway-related genes in silkworm, but little function was known on insect innate immunity. To explore the roles of JAK/STAT pathway in antifungal immune response in silkworm (Bombyx mori) against Beauveria bassiana infection, the expression patterns of B. mori C-type lectin 5 (BmCTL5) and genes encoding 6 components of JAK/STAT signaling pathway in silkworm challenged by B. bassiana were analyzed using quantitative real time PCR. Meanwhile the activation of JAK/STAT signaling pathway by various pathogenic micro-organisms and the affect of JAK/STAT signaling pathway inhibitors on antifungal activity in silkworm hemolymph was also detected. Moreover, RNAi assay of BmCTL5 and the affect on expression levels of signaling factors were also analyzed. We found that JAK/STAT pathway could be obviously activated in silkworm challenged with B. bassiana and had no response to bacteria and B. mori cytoplasmic polyhedrosis virus (BmCPV). However, the temporal expression patterns of JAK/STAT signaling pathway related genes were significantly different. B. mori downstream receptor kinase (BmDRK) might be a positive regulator of JAK/STAT signaling pathway in silkworm against B. bassiana infection. Moreover, antifungal activity assay showed that the suppression of JAK/STAT signaling pathway by inhibitors could significantly inhibit the antifungal activity in hemolymph and resulted in increased sensitivity of silkworm to B. bassiana infection, indicating that JAK/STAT signaling pathway might be involved in the synthesis and secretion of antifungal substances. The results of RNAi assays suggested that BmCTL5 might be one pattern recognition receptors for JAK/STAT signaling pathway in silkworm. These findings yield insights for better

Hemolymph Melanization in the Silkmoth Bombyx mori Involves Formation of a High Molecular Mass Complex That Metabolizes Tyrosine*

Science.gov (United States)

Clark, Kevin D.; Strand, Michael R.

2013-01-01

The phenoloxidase (PO) cascade regulates the melanization of blood (hemolymph) in insects and other arthropods. Most studies indicate that microbial elicitors activate the PO cascade, which results in processing of the zymogen PPO to PO. PO is then thought to oxidize tyrosine and o-diphenols to quinones, which leads to melanin. However, different lines of investigation raise questions as to whether these views are fully correct. Here we report that hemolymph from the silkmoth, Bombyx mori, rapidly melanizes after collection from a wound site. Prior studies indicated that in vitro activated PPO hydroxylates Tyr inefficiently. Measurement of in vivo substrate titers, however, suggested that Tyr was the only PO substrate initially present in B. mori plasma and that it is rapidly metabolized by PO. Fractionation of plasma by gel filtration chromatography followed by bioassays indicated that melanization activity was primarily associated with a high mass complex (∼670 kDa) that contained PO. The prophenoloxidase-activating protease inhibitor Egf1.0 blocked formation of this complex and Tyr metabolism, but the addition of phenylthiourea to plasma before fractionation enhanced complex formation and Tyr metabolism. Mass spectrometry analysis indicated that the complex contained PO plus other proteins. Taken together, our results indicate that wounding alone activates the PO cascade in B. mori. They also suggest that complex formation is required for efficient use of Tyr as a substrate. PMID:23553628

The light cycle controls the hatching rhythm in Bombyx mori via negative feedback loop of the circadian oscillator.

Science.gov (United States)

Tao, Hui; Li, Xue; Qiu, Jian-Feng; Liu, Heng-Jiang; Zhang, Da-Yan; Chu, Feng; Sima, Yanghu; Xu, Shi-Qing

2017-10-01

Hatching behavior is a key target in silkworm (Bombyx mori) rearing, especially for the control of Lepidoptera pests. According to previous research, hatching rhythms appear to be controlled by a clock mechanism that restricts or "gates" hatching to a particular time. However, the underlying mechanism remains elusive. Under 12-h light:12-h dark photoperiod (LD) conditions, the transcriptional levels of the chitinase5 (Cht5) and hatching enzyme-like (Hel) genes, as well as the enzymatic activities of their gene products, oscillated in time with ambient light cycles, as did the transcriptional levels of the cryptochrome 1, cryptochrome 2, period (per), and timeless genes, which are key components of the negative feedback loop of the circadian rhythm. These changes were related to the expression profile of the ecdysteroid receptor gene and the hatching behavior of B. mori eggs. However, under continuous light or dark conditions, the hatching behavior, the expression levels of Cht5 and Hel, as well as the enzymatic activities of their gene products, were not synchronized unlike under LD conditions. In addition, immunohistochemistry experiments showed that light promoted the translocation of PER from the cytoplasm to the nucleus. In conclusion, LD cycles regulate the hatching rhythm of B. mori via negative feedback loop of the circadian oscillator. © 2017 Wiley Periodicals, Inc.

Conserved synteny of genes between chromosome 15 of Bombyx mori and a chromosome of Manduca sexta shown by five-color BAC-FISH

Czech Academy of Sciences Publication Activity Database

Sahara, K.; Yoshido, A.; Marec, František; Vrbová, Iva; Zhang, H. B.; Wu, Ch. C.; Goldsmith, M. R.; Yasukochi, Y.

2007-01-01

Roč. 50, č. 11 (2007), s. 1061-1065 ISSN 0831-2796 R&D Projects: GA ČR GA206/06/1860 Grant - others:Japan Society for the Promotion of Science(JP) 18380037; US National Science Foundation(US) IBN0208388 Institutional research plan: CEZ:AV0Z50070508 Source of funding: O - operačné programy ; O - operačné programy Keywords : BAC-FISH * Bombyx mori * chromosome Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 1.785, year: 2007

Metabolic alterations and molecular mechanism in silkworm larvae ...

African Journals Online (AJOL)

Silkworm larvae, Bombyx mori (L), is an important economic insect and also a tool to convert leaf protein into silk. The industrial and commercial use of silk, the historical and economic importance of production and its application in all over the world finely contributed to the silkworm promotion as a powerful laboratory model ...

Analysis of four achaete-scute homologs in Bombyx mori reveals new viewpoints of the evolution and functions of this gene family.

Science.gov (United States)

Zhou, Qingxiang; Zhang, Tianyi; Xu, Weihua; Yu, Linlin; Yi, Yongzhu; Zhang, Zhifang

2008-03-06

achaete-scute complexe (AS-C) has been widely studied at genetic, developmental and evolutional levels. Genes of this family encode proteins containing a highly conserved bHLH domain, which take part in the regulation of the development of central nervous system and peripheral nervous system. Many AS-C homologs have been isolated from various vertebrates and invertebrates. Also, AS-C genes are duplicated during the evolution of Diptera. Functions besides neural development controlling have also been found in Drosophila AS-C genes. We cloned four achaete-scute homologs (ASH) from the lepidopteran model organism Bombyx mori, including three proneural genes and one neural precursor gene. Proteins encoded by them contained the characteristic bHLH domain and the three proneural ones were also found to have the C-terminal conserved motif. These genes regulated promoter activity through the Class A E-boxes in vitro. Though both Bm-ASH and Drosophila AS-C have four members, they are not in one by one corresponding relationships. Results of RT-PCR and real-time PCR showed that Bm-ASH genes were expressed in different larval tissues, and had well-regulated expressional profiles during the development of embryo and wing/wing disc. There are four achaete-scute homologs in Bombyx mori, the second insect having four AS-C genes so far, and these genes have multiple functions in silkworm life cycle. AS-C gene duplication in insects occurs after or parallel to, but not before the taxonomic order formation during evolution.

Somatic mutation in larvae of the silkworm, Bombyx mori, induced by heavy ion irradiation to diapause eggs

Energy Technology Data Exchange (ETDEWEB)

Kotani, Eiji; Furusawa, Toshiharu [Kyoto Inst. of Tech. (Japan). Faculty of Textile Science; Nagaoka, Shunji [Fujita Health Univ., Toyoake, Aichi (Japan). School of Health Sciences] [and others

2002-12-01

In order to investigate whether eggs of the black-striped strain (P{sup S}) of the silkworm, Bombyx mori, represent an appropriate model for estimating the biological effect of cosmic radiation, radiosensitivity of the eggs against X-rays and heavy ion particles was examined as ground-based experiments. The exposure of diapause eggs to X-rays or heavy ion particles resulted in somatic mutations appearing as a white spot on the black integument during larval stage. Irradiation of non-diapause eggs with X-rays demonstrated a significant difference in frequency of the mutation between fractionated and single administration doses, but no difference was observed in diapause eggs. Incidence of the mutation as induced by carbon ion beams for 15-day old eggs was higher for eggs that had been kept at 15 deg C than those kept at 25 deg C. Neon beam irradiation of diapause eggs displayed dose- and linear energy transfer (LET)-dependent effects, causing a maximal rate of the mutation at 150 keV/{mu}m. These results confirm that B. mori eggs represent valid models for estimating the biological effects of cosmic radiation. (author)

BmRobo1a and BmRobo1b control axon repulsion in the silkworm Bombyx mori.

Science.gov (United States)

Li, Xiao-Tong; Yu, Qi; Zhou, Qi-Sheng; Zhao, Xiao; Liu, Zhao-Yang; Cui, Wei-Zheng; Liu, Qing-Xin

2016-02-15

The development of the nervous system is based on the growth and connection of axons, and axon guidance molecules are the dominant regulators during this course. Robo, as the receptor of axon guidance molecule Slit, plays a key role as a conserved repellent cue for axon guidance during the development of the central nervous system. However, the function of Robo in the silkworm Bombyx mori is unknown. In this study, we cloned two novel robo genes in B. mori (Bmrobo1a and Bmrobo1b). BmRobo1a and BmRobo1b lack an Ig and a FNIII domain in the extracellular region and the CC0 and CC2 motifs in the intracellular region. BmRobo1a and BmRobo1b were colocalized with BmSlit in the neuropil. Knock-down of Bmrobo1a and Bmrobo1b by RNA interference (RNAi) resulted in abnormal development of axons. Our results suggest that BmRobo1a and BmRobo1b have repulsive function in axon guidance, even though their structures are different from Robo1 of other species. Copyright © 2015 Elsevier B.V. All rights reserved.

Production of recombinant Bombyx mori nucleopolyhedrovirus in silkworm by intrahaemocoelic injection with invasive diaminopimelate auxotrophic Escherichia coli containing BmNPV-Bacmid.

Science.gov (United States)

Sun, Jingchen; Yao, Lunguang; Yao, Ning; Xu, Hua; Jin, Pengfei; Kan, Yunchao

2010-12-01

The present study elaborates a cost-effective and transfectant-free method for generating recombinant Bombyx mori (silkworm) nucleopolyhedrovirus in silkworm larvae and pupae by injecting invasive Escherichia coli carrying BmBacmid [BmNPV (B. mori nucleopolyhedrovirus)-Bacmid] into larval haemocoel. Up to 109 PFU (plaque-forming units)/ml of infective recombinant baculovirus was generated in the silkworm by intrahaemocoelic injection with 106 DAP (diaminopimelic acid) auxotrophic and BmBacmid containing E. coli cells expressing both invasin and listeriolysin. Thus 1 ml of overnight culture of E. coli is sufficient to inject more than 2000 larvae, while DAP costing up to $1 is enough to inject about 4000 larvae. Recombinant proteins can be controlled to be expressed mainly in pupae by adjusting the injection dose, too. In this new method, many original manipulations have been eliminated, including BmBacmid preparation and the subsequent complex transfection procedures. Hence it is a time- and cost-saving means for large-scale injection of B. mori for recombinant baculovirus production in comparison with the traditional transfection methods, which may play an important role in the industrial development of the BmNPV-silkworm bioreactor.

Biosynthesis of insulin-silk fibroin nanoparticles conjugates and in vitro evaluation of a drug delivery system

Science.gov (United States)

Yan, Hai-Bo; Zhang, Yu-Qing; Ma, Yong-Lei; Zhou, Li-Xia

2009-11-01

Silk fibroin derived from Bombyx mori is a biomacromolecular protein with outstanding biocompatibility. When it was dissolved in highly concentrated CaCl2 solution and then the mixture of the protein and salt was subjected to desalting treatments for long time in flowing water, the resulting liquid silk was water-soluble polypeptides with different molecular masses, ranging from 8 to 70 kDa. When the liquid silk was introduced rapidly into acetone, silk protein nanoparticles with a range of 40-120 nm in diameter could be obtained. The crystalline silk nanoparticles could be conjugated covalently with insulin alone with cross-linking reagent glutaraldehyde. In vitro properties of the insulin-silk fibroin nanoparticles (Ins-SFN) bioconjugates were determined by Enzyme-Linked Immunosorbent Assay (ELISA). The optimal conditions for the biosynthesis of Ins-SFN bioconjugates were investigated. The Ins-SFN constructs obtained by 8 h of covalent cross-linking with 0.7% cross-linking reagent and the proportion of insulin and SFN being 30 IU: 15 mg showed much higher recoveries (90-115%). When insulin was coupled covalently with silk nanoparticles, the resistance of the modified insulin to trypsin digestion and in vitro stability in human serum were greatly enhanced as compared with insulin alone. The results in human serum indicated that the half-life in vitro of the biosynthesized Ins-SFN derivatives was about 2.5 times more than that of native insulin. Therefore, the silk protein nanoparticles have the potential values for being studied and developed as a new bioconjugate for enzyme/polypeptide drug delivery system.

Progeny of Palmistichus elaeisis Delvare and LaSalle (Hymenoptera: Eulophidae) parasitising pupae of Bombyx mori L. (Lepidoptera: Bombycidae) of different ages; Progenie de Palmistichus elaeisis Delvare e LaSalle (Hymenoptera:Eulophidae) parasitando pupas de Bombyx mori L. (Lepidoptera:Bombycidae) de diferentes idades

Energy Technology Data Exchange (ETDEWEB)

Pereira, Fabricio F.; Favero, Kellen; Grance, Elizangela L.V. [Universidade Federal da Grande Dourados, MS (Brazil). Fac. de Ciencias Biologicas e Ambientais], e-mail: fabriciofagundes@ufgd.edu.br, e-mail: kellenfavero@yahoo.com.br, e-mail: eli_vargasgrance@yahoo.com.br; Zanuncio, Jose C. [Universidade Federal de Vicosa (UFV), MG (Brazil). Dept. de Biologia Animal], e-mail: zanuncio@ufv.br; Serrao, Jose E. [Universidade Federal de Vicosa (UFV), MG (Brazil), Dept. de Biologia Geral], e-mail: jeserrao@ufv.br; Oliveira, Harley N. [Embrapa Agropecuaria Oeste, Dourados, MS (Brazil)], e-mail: harley@cpao.embrapa.br

2009-09-15

Palmistichus elaeisis Delvare and LaSalle is a natural pupal parasitoid of eucalyptus defoliator lepidopterans and is considered a promising biocontrol agent. However, the development of efficient rearing techniques for this natural enemy are fi rst required before it can be used in biocontrol programs. Bombyx mori L. pupae are potential alternative hosts for this parasitoid mass rearing, and they are easy to rear. Therefore, we investigated the most suitable host age and the effects of parasitoid age on progeny production of P. elaeisis. B. mori pupae, 24 h-, 48 h-, 72 h- or 96 h-old were exposed to P. elaeisis females of similar age. The duration of the life cycle (egg-adult) of P. elaeisis was not affected by the age of the parasitizing female; however, the host age affected parasitoid development. The best parasitization was obtained for 72h- to 96h-old parasitoid females when offered to 48h- to 72h-old host pupae, allowing the synchronized rearing of a large number of P. elaeisis offspring. (author)

The specificity of immune priming in silkworm, Bombyx mori, is mediated by the phagocytic ability of granular cells.

Science.gov (United States)

Wu, Gongqing; Li, Mei; Liu, Yi; Ding, Ying; Yi, Yunhong

2015-10-01

In the past decade, the phenomenon of immune priming was documented in many invertebrates in a large number of studies; however, in most of these studies, behavioral evidence was used to identify the immune priming. The underlying mechanism and the degree of specificity of the priming response remain unclear. We studied the mechanism of immune priming in the larvae of the silkworm, Bombyx mori, and analyzed the specificity of the priming response using two closely related Gram-negative pathogenic bacteria (Photorhabdus luminescens TT01 and P. luminescens H06) and one Gram-positive pathogenic bacterium (Bacillus thuringiensis HD-1). Primed with heat-killed bacteria, the B. mori larvae were more likely to survive subsequent homologous exposure (the identical bacteria used in the priming and in the subsequent challenge) than heterologous (different bacteria used in the priming and subsequent exposure) exposure to live bacteria. This result indicated that the B. mori larvae possessed a strong immune priming response and revealed a degree of specificity to TT01, H06 and HD-1 bacteria. The degree of enhanced immune protection was positively correlated with the level of phagocytic ability of the granular cells and the antibacterial activity of the cell-free hemolymph. Moreover, the granular cells of the immune-primed larvae increased the phagocytosis of a previously encountered bacterial strain compared with other bacteria. Thus, the enhanced immune protection of the B. mori larvae after priming was mediated by the phagocytic ability of the granular cells and the antibacterial activity of the hemolymph; the specificity of the priming response was primarily attributed to the phagocytosis of bacteria by the granular cells. Copyright © 2015 Elsevier Ltd. All rights reserved.

Non-Mulberry and Mulberry Silk Protein Sericins as Potential Media Supplement for Animal Cell Culture

Directory of Open Access Journals (Sweden)

Neety Sahu

2016-01-01

Full Text Available Silk protein sericins, in the recent years, find application in cosmetics and pharmaceuticals and as biomaterials. We investigate the potential of sericin, extracted from both mulberry Bombyx mori and different non-mulberry sources, namely, tropical tasar, Antheraea mylitta; muga, Antheraea assama; and eri, Samia ricini, as growth supplement in serum-free culture medium. Sericin supplemented media containing different concentrations of sericins from the different species are examined for attachment, growth, proliferation, and morphology of fibrosarcoma cells. The optimum sericin supplementation seems to vary with the source of sericins. The results indicate that all the sericins promote the growth of L929 cells in serum-free culture media; however, S. ricini sericin seems to promote better growth of cells amongst other non-mulberry sericins.

Increase in the resistance of bombyx mori L. to unfavourable environmental conditions under the effect of low-level γ-radiation

International Nuclear Information System (INIS)

Yusifov, N.I.; Agaev, F.A.; Kuzin, A.M.; AN Azerbajdzhanskoj SSR, Baku

1991-01-01

It has been shown that in cultivating Bombix mori L. larvae unfavourable summer and autumn conditions, when 50 % of larvae normally die without entering the pupation phase, chronic γ-irradiation at a low dose-rate of 1.44 cGy/day -1 and cumulative dose of 0.13 Gy drastically decreases the death rate of larvae (down to 5±2 %), and increases: total larvae mass by 38 %, living cocoon mass by 24 %, and silk coat mass by 38 %

Regenerative potential of silk conduits in repair of peripheral nerve injury in adult rats.

Science.gov (United States)

Huang, W; Begum, R; Barber, T; Ibba, V; Tee, N C H; Hussain, M; Arastoo, M; Yang, Q; Robson, L G; Lesage, S; Gheysens, T; Skaer, Nicholas J V; Knight, D P; Priestley, J V

2012-01-01

Various attempts have been made to develop artificial conduits for nerve repair, but with limited success. We describe here conduits made from Bombyx mori regenerated silk protein, and containing luminal fibres of Spidrex(®), a silk-based biomaterial with properties similar to those of spider silk. Assessment in vitro demonstrated that Spidrex(®) fibres support neurite outgrowth. For evaluation in vivo, silk conduits 10 mm in length and containing 0, 100, 200 or 300 luminal Spidrex(®) fibres, were implanted to bridge an 8 mm gap in the rat sciatic nerve. At 4 weeks, conduits containing 200 luminal Spidrex(®) fibres (PN200) supported 62% and 59% as much axon growth as autologous nerve graft controls at mid-conduit and distal nerve respectively. Furthermore, Spidrex(®) conduits displayed similar Schwann cell support and macrophage response to controls. At 12 weeks, animals implanted with PN200 conduits showed similar numbers of myelinated axons (81%) to controls, similar gastrocnemius muscle innervation, and similar hindpaw stance assessed by Catwalk footprint analysis. Plantar skin innervation was 73% of that of controls. PN200 Spidrex(®) conduits were also effective at bridging longer (11 and 13 mm) gaps. Our results show that Spidrex(®) conduits promote excellent axonal regeneration and function recovery, and may have potential for clinical application. Copyright © 2011 Elsevier Ltd. All rights reserved.

Long SAGE analysis of genes differentially expressed in the midgut ...

African Journals Online (AJOL)

Long SAGE analysis of genes differentially expressed in the midgut and silk gland between the sexes of the silkwormBombyx mori. Liping Gan, Ying Wang, Jian Xi, Yanshan Niu, Hongyou Qin, Yanghu Sima, Shiqing Xu ...

Bombyx mori ABC transporter C2 structures responsible for the receptor function of Bacillus thuringiensis Cry1Aa toxin.

Science.gov (United States)

Tanaka, Shiho; Endo, Haruka; Adegawa, Satomi; Iizuka, Ami; Imamura, Kazuhiro; Kikuta, Shingo; Sato, Ryoichi

2017-12-01

Because Bombyx mori ABC transporter C2 (BmABCC2) has 1000-fold higher potential than B. mori cadherin-like protein as a receptor for Bacillus thuringiensis Cry1Aa toxin (Tanaka et al., 2013), the gate-opening ability of the latent pore under six extracellular loops (ECLs) of BmABCC2 was expected to be the reason for its higher potential (Heckel, 2012). In this study, cell swelling assays in Sf9 cells showed that BmABCC2 mutants lacking substrate-excreting activity retained receptor activity, indicating that the gate-opening activity of BmABCC2 is not responsible for Cry1Aa toxicity. The analysis of 29 BmABCC2 mutants demonstrated that 770 DYWL 773 of ECL 4 comprise a putative binding site to Cry1Aa. This suggests that specific toxicity of Cry1Aa toxin to a restricted range of lepidopteran insects is dependent on conservation and variation in the amino acid residues around 770 DYWL 773 of ECL 4 in the ABCC2. Copyright © 2017 Elsevier Ltd. All rights reserved.

Comparative Study of Biological Characteristics of Larvae, Crude and Dried Cocoon in 7 Races of Silkworm Bombyx mori L., Raised in Transylvania Area

Directory of Open Access Journals (Sweden)

Emilia Maria Furdui

2010-05-01

Full Text Available 7 monovoltine races of Romanian silkworm Bombyx mori L. were breeded in specific Transylvania conditions, assuring the same microclimate conditions, being fed with the same mulberry leaves (Ukraina 107. The results obtained showed a high homogeneity, the differences were due to the variability and genotype characteristic for each individual of every race. Results and standard deviations are within the race standard. The study permitted a ierarchy of the races, following the biological characteristics, microclimate conditions, quantity, quality and breeding technology.

Molecular phylogeny of the domesticated silkworm, Bombyx mori

Indian Academy of Sciences (India)

Among 14 strains of B. mori, sequence divergence was small and the most divergence was seen between strains Yanhe-1 and Chuxiong, whose sequences branched off from those of the other B. mori strains on the phylogenetic tree. From this and from historical records, we infer that the strains Yanhe-1 and Chuxiong ...

The Effect of Zinc Supplementation on the Production Parameters of Bombyx mori L. species

Directory of Open Access Journals (Sweden)

Mihai Benţea

2012-05-01

Full Text Available This research aimed to evaluate the influence of Zinc, administered as food supplement for silkworm (Bombyx moriL. on the larvae weight, the weight of the serigene gland, cocoon weight, cocoon shell. The research has been carried out on 5 groups of silkworms one control group (Gr.1 and 4 experimental groups (4 groups receiving zinc, consisting of 50 larvae/group. Zinc was administered in doses of 17, 34, 68 and 136 mg kg-1 larvae - Gr.2-Gr.5. The use of Zinc determined a very significant increase of the larvae weight, to group Gr.5 followed by groups Gr.4, Gr.3 and Gr.2 compared to the control group. The use of Zinc positively influenced the mass of the serigene glands, the cocoon weight, cocoon shell. The Zn content of the pupae from the experimental groups was higher compared to the one recorded in the control group.

Download this PDF file

African Journals Online (AJOL)

RAGHAVENDRA

silk ratio of silkworm races were registered from one time two times bed .... silkworm (Bombyx mori), a monophagous insect, feeds on only mulberry .... fecundity and egg hatching with lower larval and pupal durations ...... In: Success with Value.

Molybdenum cofactor deficiency causes translucent integument, male-biased lethality, and flaccid paralysis in the silkworm Bombyx mori.

Science.gov (United States)

Fujii, Tsuguru; Yamamoto, Kimiko; Banno, Yutaka

2016-06-01

Uric acid accumulates in the epidermis of Bombyx mori larvae and renders the larval integument opaque and white. Yamamoto translucent (oya) is a novel spontaneous mutant with a translucent larval integument and unique phenotypic characteristics, such as male-biased lethality and flaccid larval paralysis. Xanthine dehydrogenase (XDH) that requires a molybdenum cofactor (MoCo) for its activity is a key enzyme for uric acid synthesis. It has been observed that injection of a bovine xanthine oxidase, which corresponds functionally to XDH and contains its own MoCo activity, changes the integuments of oya mutants from translucent to opaque and white. This finding suggests that XDH/MoCo activity might be defective in oya mutants. Our linkage analysis identified an association between the oya locus and chromosome 23. Because XDH is not linked to chromosome 23 in B. mori, MoCo appears to be defective in oya mutants. In eukaryotes, MoCo is synthesized by a conserved biosynthesis pathway governed by four loci (MOCS1, MOCS2, MOCS3, and GEPH). Through a candidate gene approach followed by sequence analysis, a 6-bp deletion was detected in an exon of the B. mori molybdenum cofactor synthesis-step 1 gene (BmMOCS1) in the oya strain. Moreover, recombination was not observed between the oya and BmMOCS1 loci. These results indicate that the BmMOCS1 locus is responsible for the oya locus. Finally, we discuss the potential cause of male-biased lethality and flaccid paralysis observed in the oya mutants. Copyright © 2016 Elsevier Ltd. All rights reserved.

Genetic diversity among silkworm (Bombyx mori L., Lep., Bombycidae) germplasms revealed by microsatellites.

Science.gov (United States)

Li, Muwang; Shen, Li; Xu, Anying; Miao, Xuexia; Hou, Chengxiang; Sun, Pingjiang; Zhang, Yuehua; Huang, Yongping

2005-10-01

To determine genetic relationships among strains of silkworm, Bombyx mori L., 31 strains with different origins, number of generations per year, number of molts per generation, and morphological characters were studied using simple sequence repeat (SSR) markers. Twenty-six primer pairs flanking microsatellite sequences in the silkworm genome were assayed. All were polymorphic and unambiguously separated silkworm strains from each other. A total of 188 alleles were detected with a mean value of 7.2 alleles/locus (range 2-17). The average heterozygosity value for each SSR locus ranged from 0 to 0.60, and the highest one was 0.96 (Fl0516 in 4013). The mean polymorphism index content (PIC) was 0.66 (range 0.12-0.89). Unweighted pair group method with arithmetic means (UPGMA) cluster analysis of Nei's genetic distance grouped silkworm strains based on their origin. Seven major ecotypic silkworm groups were analyzed. Principal components analysis (PCA) for SSR data support their UPGMA clustering. The results indicated that SSR markers are an efficient tool for fingerprinting cultivars and conducting genetic-diversity studies in the silkworm.

Molecular Characterization of Bombyx mori Cytoplasmic Polyhedrosis Virus Genome Segment 4

Science.gov (United States)

Ikeda, Keiko; Nagaoka, Sumiharu; Winkler, Stefan; Kotani, Kumiko; Yagi, Hiroaki; Nakanishi, Kae; Miyajima, Shigetoshi; Kobayashi, Jun; Mori, Hajime

2001-01-01

The complete nucleotide sequence of the genome segment 4 (S4) of Bombyx mori cytoplasmic polyhedrosis virus (BmCPV) was determined. The 3,259-nucleotide sequence contains a single long open reading frame which spans nucleotides 14 to 3187 and which is predicted to encode a protein with a molecular mass of about 130 kDa. Western blot analysis showed that S4 encodes BmCPV protein VP3, which is one of the outer components of the BmCPV virion. Sequence analysis of the deduced amino acid sequence of BmCPV VP3 revealed possible sequence homology with proteins from rice ragged stunt virus (RRSV) S2, Nilaparvata lugens reovirus S4, and Fiji disease fijivirus S4. This may suggest that plant reoviruses originated from insect viruses and that RRSV emerged more recently than other plant reoviruses. A chimeric protein consisting of BmCPV VP3 and green fluorescent protein (GFP) was constructed and expressed with BmCPV polyhedrin using a baculovirus expression vector. The VP3-GFP chimera was incorporated into BmCPV polyhedra and released under alkaline conditions. The results indicate that specific interactions occur between BmCPV polyhedrin and VP3 which might facilitate BmCPV virion occlusion into the polyhedra. PMID:11134312

Developmental Changes for the Hemolymph Metabolome of Silkworm (Bombyx moriL.)

Science.gov (United States)

Zhou, Lihong; Li, Huihui; Hao, Fuhua; Li, Ning; Liu, Xin; Wang, Guoliang; Wang, Yulan; Tang, Huiru

2015-01-01

Silkworm (Bombyx mori) is a lepidopteran-holometabolic model organism. To understand its developmental biochemistry, we characterized the larval hemolymph metabonome from the third instar to prepupa stage using 1H NMR spectroscopy whilst hemolymph fatty acid composition using GC-FID/MS. We unambiguously assigned more than 60 metabolites, among which tyrosine-o-β-glucuronide, mesaconate, homocarnosine, and picolinate were reported for the first time from the silkworm hemolymph. Phosphorylcholine was the most abundant metabolite in all developmental stages with exception for the periods before the third and fourth molting. We also found obvious developmental dependence for the hemolymph metabonome involving multiple pathways including protein biosyntheses, glycolysis, TCA cycle, the metabolisms of choline amino acids, fatty acids, purines, and pyrimidines. Most hemolymph amino acids had two elevations during the feeding period of the fourth instar and prepupa stage. Trehalose was the major blood sugar before day 8 of the fifth instar, whereas glucose became the major blood sugar after spinning. C16:0, C18:0 and its unsaturated forms were dominant fatty acids in hemolymph. The developmental changes of hemolymph metabonome were associated with dietary nutrient intakes, biosyntheses of cell membrane, pigments, proteins, and energy metabolism. These findings offered essential biochemistry information in terms of the dynamic metabolic changes during silkworm development. PMID:25825269

Analysis of four achaete-scute homologs in Bombyx mori reveals new viewpoints of the evolution and functions of this gene family

Directory of Open Access Journals (Sweden)

Yi Yongzhu

2008-03-01

Full Text Available Abstract Background achaete-scute complexe (AS-C has been widely studied at genetic, developmental and evolutional levels. Genes of this family encode proteins containing a highly conserved bHLH domain, which take part in the regulation of the development of central nervous system and peripheral nervous system. Many AS-C homologs have been isolated from various vertebrates and invertebrates. Also, AS-C genes are duplicated during the evolution of Diptera. Functions besides neural development controlling have also been found in Drosophila AS-C genes. Results We cloned four achaete-scute homologs (ASH from the lepidopteran model organism Bombyx mori, including three proneural genes and one neural precursor gene. Proteins encoded by them contained the characteristic bHLH domain and the three proneural ones were also found to have the C-terminal conserved motif. These genes regulated promoter activity through the Class A E-boxes in vitro. Though both Bm-ASH and Drosophila AS-C have four members, they are not in one by one corresponding relationships. Results of RT-PCR and real-time PCR showed that Bm-ASH genes were expressed in different larval tissues, and had well-regulated expressional profiles during the development of embryo and wing/wing disc. Conclusion There are four achaete-scute homologs in Bombyx mori, the second insect having four AS-C genes so far, and these genes have multiple functions in silkworm life cycle. AS-C gene duplication in insects occurs after or parallel to, but not before the taxonomic order formation during evolution.

Disruption of Bombyx mori nucleopolyhedrovirus ORF71 (Bm71) results in inefficient budded virus production and decreased virulence in host larvae.

Science.gov (United States)

Zhang, Min-Juan; Cheng, Ruo-Lin; Lou, Yi-Han; Ye, Wan-Lu; Zhang, Tao; Fan, Xiao-Ying; Fan, Hai-Wei; Zhang, Chuan-Xi

2012-08-01

The Bombyx mori nucleopolyhedrovirus (BmNPV) is a baculovirus that selectively infects domestic silkworm. BmNPV ORF71 (Bm71) is not a core set gene in baculovirus and shares 92 % amino acid sequence identity with Autographa californica multinucleocapsid NPV ORF88 (Ac88/cg30). Previously, it has been reported that virus lacking Ac88 had no striking phenotypes in cell lines or host larvae. However, the exact role of Bm71 during BmNPV life cycle remains unknown. In the present study, we constructed a Bm71-disrupted (Bm71-D) virus and assessed the effect of the Bm71 disruption on viral replication and viral phenotype throughout the viral life cycle. Results showed that the Bm71-D bacmid could successfully transfect Bm5 cell lines and produce infectious budded virus (BV). But the BV titer was 10- to 100-fold lower than that of the wild-type (WT) virus during infection, and the decreased BV titer was rescued by Bm71 gene repair virus (Bm71-R). A larval bioassay showed that Bm71-D virus took 7.5 h longer than the WT to kill Bombyx mori larvae. Transmission electron microscopy analysis indicated that the Bm71-D virus-infected cells had typical virogenic stroma, bundles of nucleocapsids and polyhedra. Taken together, these results suggest that Bm71 has important implications for determining BV yield and virulence in viral life cycle even though it is not an essential gene for replication of BmNPV.

Sexually dimorphic traits in the silkworm, Bombyx mori, are regulated by doublesex.

Science.gov (United States)

Xu, Jun; Zhan, Shuai; Chen, Shuqing; Zeng, Baosheng; Li, Zhiqian; James, Anthony A; Tan, Anjiang; Huang, Yongping

2017-01-01

The DM domain genes, doublesex (dsx) in insects, or their structural homologs, male abnormal 3 (mab-3) in nematodes and Dmrt1 (doublesex and mab-3-related transcription factor 1) in mammals, are downstream regulators of the sex determination pathway that control sexually dimorphic development. Despite the functional importance of dsx and its potential applications in sterile insect technologies (SITs), the mechanisms by which it controls sexually dimorphic traits and the subsequent developmental gene networks in insects are poorly understood. Phylogenetic analyses indicate that insect dsx genes have sex-specific alternative splicing isoforms, whereas other taxa do not. We exploited genome editing and transgenesis technologies to induce mutations in either the male-specific isoform (dsx M ) or common region (dsx C ) of dsx in the somatic tissues of the lepidopteran model insect Bombyx mori. Disruptions of gene function produced either male-specific sexually-dimorphic defects or intersexual phenotypes; these results differ from those observed in other insects, including Drosophila melanogaster. Our data provide insights into the divergence of the insect sex determination pathways related to the most conserved downstream component dsx. Copyright © 2016 Elsevier Ltd. All rights reserved.

Molecular characterization of a peritrophic membrane protein from the silkworm, Bombyx mori.

Science.gov (United States)

Hu, Xiaolong; Chen, Lin; Yang, Rui; Xiang, Xingwei; Wu, Xiaofeng

2013-02-01

The peritrophic membrane lines the gut of most insects at one or more stages of their life cycles. It facilitates the digestive processes in the guts and protects from invasion by pathogens or food particles. In the current study, a novel PM protein, designated as BmMtch, was identified from the silkworm, Bombyx mori. The open reading frame of BmMtch is 888 bp in length, encoding 295 amino acid residues consisting of two domains (Mito_carr domains) and three transmembrane regions. They are localized on the 11th chromosome as single copy with one exon only. Quantitative real time PCR analysis (qRT-PCR) revealed that BmMtch was mainly expressed in larval fat bodies, Malpighian tubules, testis and ovaries, and could be detected through all stages of the life cycle of silkworm. Immuno-fluorescence analysis indicated that BmMtch was localized within the goblet cell of larval midgut. Western blotting analysis showed that BmMtch were detected in total proteins of PM and larval midgut. The characteristics of BmMtch indicated that BmMtch represents a novel member of insect PM proteins, without chitin-binding domains.

Progênie de Palmistichus elaeisis Delvare & LaSalle (Hymenoptera: Eulophidae) parasitando pupas de Bombyx mori L. (Lepidoptera: Bombycidae) de diferentes idades

OpenAIRE

Pereira, Fabricio F; Zanuncio, José C; Serrão, José E; Oliveira, Harley N; Fávero, Kellen; Grance, Elizangela L V

2009-01-01

Palmistichus elaeisis Delvare & LaSalle é um parasitóide pupal natural de pupas de lepidópteros desfolhadores de eucalipto e é considerado um promissor agente de controle biológico. No entanto, o desenvolvimento de técnicas de criação eficientes desse inimigo natural é inicialmente necessário para que ele possa ser utilizado em programas de controle biológico. Pupas de Bombyx mori L. são hospedeiras alternativas em potencial para criação massal de P. elaeisis. Por isto, nós avaliamos a idade ...

Identification and characteristics of microRNAs from Bombyx mori

Directory of Open Access Journals (Sweden)

Gao Xiaolian

2008-05-01

Full Text Available Abstract Background MicroRNAs (miRNAs are small RNA molecules that regulate gene expression by targeting messenger RNAs (mRNAs and causing mRNA cleavage or translation blockage. Of the 355 Arthropod miRNAs that have been identified, only 21 are B. mori miRNAs that were predicted computationally; of these, only let-7 has been confirmed by Northern blotting. Results Combining a computational method based on sequence homology searches with experimental identification based on microarray assays and Northern blotting, we identified 46 miRNAs, an additional 21 plausible miRNAs, and a novel small RNA in B. mori. The latter, bmo-miR-100-like, was identified using the known miRNA aga-miR-100 as a probe; bmo-miR-100-like was detected by microarray assay and Northern blotting, but its precursor sequences did not fold into a hairpin structure. Among these identified miRNAs, we found 12 pairs of miRNAs and miRNA*s. Northern blotting revealed that some B. mori miRNA genes were expressed only during specific stages, indicating that B. mori miRNA genes (e.g., bmo-miR-277 have developmentally regulated patterns of expression. We identified two miRNA gene clusters in the B. mori genome. bmo-miR-2b, which is found in the gene cluster bmo-miR-2a-1/bmo-miR-2a-1*/bmo-miR-2a-2/bmo-miR-2b/bmo-miR-13a*/bmo-miR-13b, encodes a newly identified member of the mir-2 family. Moreover, we found that methylation can increase the sensitivity of a DNA probe used to detect a miRNA by Northern blotting. Functional analysis revealed that 11 miRNAs may regulate 13 B. mori orthologs of the 25 known Drosophila miRNA-targeted genes according to the functional conservation. We predicted the binding sites on the 1671 3'UTR of B. mori genes; 547 targeted genes, including 986 target sites, were predicted. Of these target sites, 338 had perfect base pairing to the seed region of 43 miRNAs. From the predicted genes, 61 genes, each of them with multiple predicted target sites, should be

Identification of a microsporidian isolate from Cnaphalocrocis Medinalis and its pathogenicity to Bombyx mori.

Science.gov (United States)

Huang, Xuhua; Qi, Guangjun; Pan, Zhixin; Zhu, Fangrong; Huang, Yuanjiao; Wu, Yonghu

2014-11-01

A microsporidian, CmM2, was isolated from Cnaphalocrocis medinalis. The biological characters, molecular analysis and pathogenicity of CmM2 were studied. The spore of CmM2 is long oval in shape and 3.45 ± 0.25 × 1.68 ± 0.18 µm in size, the life cycle includes meronts, sporonts, sporoblasts, and spores, with typical diplokaryon in each stage, propagated in binary fission. There is positive coagulation reaction between CmM2 and the polyclonal antibody of Nosema bombycis (N.b.). CmM2 spores is binuclear, and has 10-12 polar filament coils. The small subunit ribosomal RNA (SSU rRNA) gene sequence of CmM2 was obtained by PCR amplification and sequencing, the phylogenetic tree based on SSU rRNA sequences had been constructed, and the similarity and genetic distance of SSU rRNA sequences were analyzed, showed that CmM2 was grouped in the Nosema clade. The 50% infectious concentration of CmM2 to Bombyx mori is 4.72 × 10(4)  spores ml(-1) , and the germinative infection rate is 12.33%. The results showed that CmM2 is classified into genus Nosema, as Nosema sp. CmM2, and has a heavy infectivity to B. mori. The result indicated as well that it is valuable taxonomic determination for microsporidian isolates based on both biological characters and molecular evidence. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

[Progeny of Palmistichus elaeisis Delvare & LaSalle (Hymenoptera: Eulophidae) parasitising pupae of Bombyx mori L. (Lepidoptera: Bombycidae) of different ages].

Science.gov (United States)

Pereira, Fabricio F; Zanuncio, José C; Serrão, José E; Oliveira, Harley N; Fávero, Kellen; Grance, Elizangela L V

2009-01-01

Palmistichus elaeisis Delvare & LaSalle is a natural pupal parasitoid of eucalyptus defoliator lepidopterans and is considered a promising biocontrol agent. However, the development of efficient rearing techniques for this natural enemy are first required before it can be used in biocontrol programs. Bombyx mori L. pupae are potential alternative hosts for this parasitoid mass rearing, and they are easy to rear. Therefore, we investigated the most suitable host age and the effects of parasitoid age on progeny production of P. elaeisis. B. mori pupae, 24 h-, 48 h-, 72 h- or 96 h-old were exposed to P. elaeisis females of similar age. The duration of the life cycle (egg-adult) of P. elaeisis was not affected by the age of the parasitizing female; however, the host age affected parasitoid development. The best parasitization was obtained for 72 h- to 96 h-old parasitoid females when offered to 48 h- to 72 h-old host pupae, allowing the synchronized rearing of a large number of P. elaeisis offspring.

Efisiensi Konsumsi Pakan Dan Laju Respirasi Ulat Sutera Bombyx mori L. (Lepidoptera: Bombicidae) Yang Diberi Daun Murbei (Morus sp.) Yang Mengandung Vitamin B1 (TIAMIN)

OpenAIRE

Hayani, Rizma

2014-01-01

The Effect of Mulberry (Morus sp.) Leave that Contain Vitamin B1 (Thiamine) on the Efficiency of Feed Consumption and Respiration Rate of Silkworm Bombyx mori L. (Lepidoptera: Bombicidae)” has been carried out in the Laboratory of Genetics, Faculty of Mathematics and Natural Sciences, University of Sumatra Utara, Medan. This study used Complete Random Design (CRD) with 5 treatments and 3 replications each replication consisted of 10 silkworm. The treatmants that vitamin B1 concentration of mg...

The silkworm (Bombyx mori microRNAs and their expressions in multiple developmental stages.

Directory of Open Access Journals (Sweden)

Xiaomin Yu

Full Text Available BACKGROUND: MicroRNAs (miRNAs play crucial roles in various physiological processes through post-transcriptional regulation of gene expressions and are involved in development, metabolism, and many other important molecular mechanisms and cellular processes. The Bombyx mori genome sequence provides opportunities for a thorough survey for miRNAs as well as comparative analyses with other sequenced insect species. METHODOLOGY/PRINCIPAL FINDINGS: We identified 114 non-redundant conserved miRNAs and 148 novel putative miRNAs from the B. mori genome with an elaborate computational protocol. We also sequenced 6,720 clones from 14 developmental stage-specific small RNA libraries in which we identified 35 unique miRNAs containing 21 conserved miRNAs (including 17 predicted miRNAs and 14 novel miRNAs (including 11 predicted novel miRNAs. Among the 114 conserved miRNAs, we found six pairs of clusters evolutionarily conserved cross insect lineages. Our observations on length heterogeneity at 5' and/or 3' ends of nine miRNAs between cloned and predicted sequences, and three mature forms deriving from the same arm of putative pre-miRNAs suggest a mechanism by which miRNAs gain new functions. Analyzing development-related miRNAs expression at 14 developmental stages based on clone-sampling and stem-loop RT PCR, we discovered an unusual abundance of 33 sequences representing 12 different miRNAs and sharply fluctuated expression of miRNAs at larva-molting stage. The potential functions of several stage-biased miRNAs were also analyzed in combination with predicted target genes and silkworm's phenotypic traits; our results indicated that miRNAs may play key regulatory roles in specific developmental stages in the silkworm, such as ecdysis. CONCLUSIONS/SIGNIFICANCE: Taking a combined approach, we identified 118 conserved miRNAs and 151 novel miRNA candidates from the B. mori genome sequence. Our expression analyses by sampling miRNAs and real-time PCR over

Efficient silkworm expression of human GPCR (nociceptin receptor) by a Bombyx mori bacmid DNA system

International Nuclear Information System (INIS)

Kajikawa, Mizuho; Sasaki, Kaori; Wakimoto, Yoshitaro; Toyooka, Masaru; Motohashi, Tomoko; Shimojima, Tsukasa; Takeda, Shigeki; Park, Enoch Y.; Maenaka, Katsumi

2009-01-01

Guanine nucleotide-binding protein (G protein) coupled receptors (GPCRs) are frequently expressed by a baculovirus expression vector system (BEVS). We recently established a novel BEVS using the bacmid system of Bombyx mori nucleopolyhedrovirus (BmNPV), which is directly applicable for protein expression in silkworms. Here, we report the first example of GPCR expression in silkworms by the simple injection of BmNPV bacmid DNA. Human nociceptin receptor, an inhibitory GPCR, and its fusion protein with inhibitory G protein alpha subunit (G i α) were both successfully expressed in the fat bodies of silkworm larvae as well as in the BmNPV viral fraction. Its yield was much higher than that from Sf9 cells. The microsomal fractions including the nociceptin receptor fusion, which are easily prepared by only centrifugation steps, exhibited [ 35 S]GTPγS-binding activity upon specific stimulation by nociceptin. Therefore, this rapid method is easy-to-use and has a high expression level, and thus will be an important tool for human GPCR production.

FLP recombinase-mediated site-specific recombination in silkworm, Bombyx mori.

Directory of Open Access Journals (Sweden)

Ding-Pei Long

Full Text Available A comprehensive understanding of gene function and the production of site-specific genetically modified mutants are two major goals of genetic engineering in the post-genomic era. Although site-specific recombination systems have been powerful tools for genome manipulation of many organisms, they have not yet been established for use in the manipulation of the silkworm Bombyx mori genome. In this study, we achieved site-specific excision of a target gene at predefined chromosomal sites in the silkworm using a FLP/FRT site-specific recombination system. We first constructed two stable transgenic target silkworm strains that both contain a single copy of the transgene construct comprising a target gene expression cassette flanked by FRT sites. Using pre-blastoderm microinjection of a FLP recombinase helper expression vector, 32 G3 site-specific recombinant transgenic individuals were isolated from five of 143 broods. The average frequency of FLP recombinase-mediated site-specific excision in the two target strains genome was approximately 3.5%. This study shows that it is feasible to achieve site-specific recombination in silkworms using the FLP/FRT system. We conclude that the FLP/FRT system is a useful tool for genome manipulation in the silkworm. Furthermore, this is the first reported use of the FLP/FRT system for the genetic manipulation of a lepidopteran genome and thus provides a useful reference for the establishment of genome manipulation technologies in other lepidopteran species.

Silk as a biocohesive sacrificial binder in the fabrication of hydroxyapatite load bearing scaffolds.

Science.gov (United States)

McNamara, Stephanie L; Rnjak-Kovacina, Jelena; Schmidt, Daniel F; Lo, Tim J; Kaplan, David L

2014-08-01

Limitations of current clinical methods for bone repair continue to fuel the demand for a high strength, bioactive bone replacement material. Recent attempts to produce porous scaffolds for bone regeneration have been limited by the intrinsic weakness associated with high porosity materials. In this study, ceramic scaffold fabrication techniques for potential use in load-bearing bone repairs have been developed using naturally derived silk from Bombyx mori. Silk was first employed for ceramic grain consolidation during green body formation, and later as a sacrificial polymer to impart porosity during sintering. These techniques allowed preparation of hydroxyapatite (HA) scaffolds that exhibited a wide range of mechanical and porosity profiles, with some displaying unusually high compressive strength up to 152.4 ± 9.1 MPa. Results showed that the scaffolds exhibited a wide range of compressive strengths and moduli (8.7 ± 2.7 MPa to 152.4 ± 9.1 MPa and 0.3 ± 0.1 GPa to 8.6 ± 0.3 GPa) with total porosities of up to 62.9 ± 2.7% depending on the parameters used for fabrication. Moreover, HA-silk scaffolds could be molded into large, complex shapes, and further machined post-sinter to generate specific three-dimensional geometries. Scaffolds supported bone marrow-derived mesenchymal stem cell attachment and proliferation, with no signs of cytotoxicity. Therefore, silk-fabricated HA scaffolds show promise for load bearing bone repair and regeneration needs. Copyright © 2014 Elsevier Ltd. All rights reserved.

Comparative Study of Ultrasonication-Induced and Naturally Self-Assembled Silk Fibroin-Wool Keratin Hydrogel Biomaterials.

Science.gov (United States)

Vu, Trang; Xue, Ye; Vuong, Trinh; Erbe, Matthew; Bennet, Christopher; Palazzo, Ben; Popielski, Lucas; Rodriguez, Nelson; Hu, Xiao

2016-09-07

This study reports the formation of biocompatible hydrogels using protein polymers from natural silk cocoon fibroins and sheep wool keratins. Silk fibroin protein contains β-sheet secondary structures, allowing for the formation of physical cross-linkers in the hydrogels. Comparative studies were performed on two groups of samples. In the first group, ultrasonication was used to induce a quick gelation of a protein aqueous solution, enhancing the ability of Bombyx mori silk fibroin chains to quickly entrap the wool keratin protein molecules homogenously. In the second group, silk/keratin mixtures were left at room temperature for days, resulting in naturally-assembled gelled solutions. It was found that silk/wool blended solutions can form hydrogels at different mixing ratios, with perfectly interconnected gel structure when the wool content was less than 30 weight percent (wt %) for the first group (ultrasonication), and 10 wt % for the second group (natural gel). Differential scanning calorimetry (DSC) and temperature modulated DSC (TMDSC) were used to confirm that the fibroin/keratin hydrogel system was well-blended without phase separation. Fourier transform infrared spectroscopy (FTIR) was used to investigate the secondary structures of blended protein gels. It was found that intermolecular β-sheet contents significantly increase as the system contains more silk for both groups of samples, resulting in stable crystalline cross-linkers in the blended hydrogel structures. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) were used to analyze the samples' characteristic morphology on both micro- and nanoscales, which showed that ultrasonic waves can significantly enhance the cross-linker formation and avoid phase separation between silk and keratin molecules in the blended systems. With the ability to form cross-linkages non-chemically, these silk/wool hydrogels may be economically useful for various biomedical applications, thanks to the

Comparative Study of Ultrasonication-Induced and Naturally Self-Assembled Silk Fibroin-Wool Keratin Hydrogel Biomaterials

Directory of Open Access Journals (Sweden)

Trang Vu

2016-09-01

Full Text Available This study reports the formation of biocompatible hydrogels using protein polymers from natural silk cocoon fibroins and sheep wool keratins. Silk fibroin protein contains β-sheet secondary structures, allowing for the formation of physical cross-linkers in the hydrogels. Comparative studies were performed on two groups of samples. In the first group, ultrasonication was used to induce a quick gelation of a protein aqueous solution, enhancing the ability of Bombyx mori silk fibroin chains to quickly entrap the wool keratin protein molecules homogenously. In the second group, silk/keratin mixtures were left at room temperature for days, resulting in naturally-assembled gelled solutions. It was found that silk/wool blended solutions can form hydrogels at different mixing ratios, with perfectly interconnected gel structure when the wool content was less than 30 weight percent (wt % for the first group (ultrasonication, and 10 wt % for the second group (natural gel. Differential scanning calorimetry (DSC and temperature modulated DSC (TMDSC were used to confirm that the fibroin/keratin hydrogel system was well-blended without phase separation. Fourier transform infrared spectroscopy (FTIR was used to investigate the secondary structures of blended protein gels. It was found that intermolecular β-sheet contents significantly increase as the system contains more silk for both groups of samples, resulting in stable crystalline cross-linkers in the blended hydrogel structures. Scanning electron microscopy (SEM and atomic force microscopy (AFM were used to analyze the samples’ characteristic morphology on both micro- and nanoscales, which showed that ultrasonic waves can significantly enhance the cross-linker formation and avoid phase separation between silk and keratin molecules in the blended systems. With the ability to form cross-linkages non-chemically, these silk/wool hydrogels may be economically useful for various biomedical applications

Formation of silk fibroin nanoparticles in water-miscible organic solvent and their characterization

Science.gov (United States)

Zhang, Yu-Qing; Shen, Wei-De; Xiang, Ru-Li; Zhuge, Lan-Jian; Gao, Wei-Jian; Wang, Wen-Bao

2007-10-01

When Silk fibre derived from Bombyx mori, a native biopolymer, was dissolved in highly concentrated neutral salts such as CaCl2, the regenerated liquid silk, a gradually degraded peptide mixture of silk fibroin, could be obtained. The silk fibroin nanoparticles were prepared rapidly from the liquid silk by using water-miscible protonic and polar aprotonic organic solvents. The nanoparticles are insoluble but well dispersed and stable in aqueous solution and are globular particles with a range of 35-125 nm in diameter by means of TEM, SEM, AFM and laser sizer. Over one half of the ɛ-amino groups exist around the protein nanoparticles by using a trinitrobenzenesulfonic acid (TNBS) method. Raman spectra shows the tyrosine residues on the surface of the globules are more exposed than those on native silk fibers. The crystalline polymorph and conformation transition of the silk nanoparticles from random-coil and α-helix form (Silk I) into anti-parallel β-sheet form (Silk II) are investigated in detail by using infrared, fluorescence and Raman spectroscopy, DSC, 13C CP-MAS NMR and electron diffraction. X-ray diffraction of the silk nanoparticles shows that the nanoparticles crystallinity is about four fifths of the native fiber. Our results indicate that the degraded peptide chains of the regenerated silk is gathered homogeneously or heterogeneously to form a looser globular structure in aqueous solution. When introduced into excessive organic solvent, the looser globules of the liquid silk are rapidly dispersed and simultaneously dehydrated internally and externally, resulting in the further chain-chain contact, arrangement of those hydrophobic domains inside the globules and final formation of crystalline silk nanoparticles with β-sheet configuration. The morphology and size of the nanoparticles are relative to the kinds, properties and even molecular structures of organic solvents, and more significantly to the looser globular substructure of the degraded silk

Formation of silk fibroin nanoparticles in water-miscible organic solvent and their characterization

International Nuclear Information System (INIS)

Zhang Yuqing; Shen Weide; Xiang Ruli; Zhuge Lanjian; Gao Weijian; Wang Wenbao

2007-01-01

When Silk fibre derived from Bombyx mori, a native biopolymer, was dissolved in highly concentrated neutral salts such as CaCl 2 , the regenerated liquid silk, a gradually degraded peptide mixture of silk fibroin, could be obtained. The silk fibroin nanoparticles were prepared rapidly from the liquid silk by using water-miscible protonic and polar aprotonic organic solvents. The nanoparticles are insoluble but well dispersed and stable in aqueous solution and are globular particles with a range of 35-125 nm in diameter by means of TEM, SEM, AFM and laser sizer. Over one half of the ε-amino groups exist around the protein nanoparticles by using a trinitrobenzenesulfonic acid (TNBS) method. Raman spectra shows the tyrosine residues on the surface of the globules are more exposed than those on native silk fibers. The crystalline polymorph and conformation transition of the silk nanoparticles from random-coil and α-helix form (Silk I) into anti-parallel β-sheet form (Silk II) are investigated in detail by using infrared, fluorescence and Raman spectroscopy, DSC, 13 C CP-MAS NMR and electron diffraction. X-ray diffraction of the silk nanoparticles shows that the nanoparticles crystallinity is about four fifths of the native fiber. Our results indicate that the degraded peptide chains of the regenerated silk is gathered homogeneously or heterogeneously to form a looser globular structure in aqueous solution. When introduced into excessive organic solvent, the looser globules of the liquid silk are rapidly dispersed and simultaneously dehydrated internally and externally, resulting in the further chain-chain contact, arrangement of those hydrophobic domains inside the globules and final formation of crystalline silk nanoparticles with β-sheet configuration. The morphology and size of the nanoparticles are relative to the kinds, properties and even molecular structures of organic solvents, and more significantly to the looser globular substructure of the degraded silk

Formation of silk fibroin nanoparticles in water-miscible organic solvent and their characterization

Energy Technology Data Exchange (ETDEWEB)

Zhang Yuqing, E-mail: yqzhang@public1.sz.js.cn; Shen Weide; Xiang Ruli [Soochow University, Silk Biotechnol. Lab., School of Life Science (China); Zhuge Lanjian; Gao Weijian; Wang Wenbao [Soochow University, Analytical Center (China)

2007-10-15

When Silk fibre derived from Bombyx mori, a native biopolymer, was dissolved in highly concentrated neutral salts such as CaCl{sub 2}, the regenerated liquid silk, a gradually degraded peptide mixture of silk fibroin, could be obtained. The silk fibroin nanoparticles were prepared rapidly from the liquid silk by using water-miscible protonic and polar aprotonic organic solvents. The nanoparticles are insoluble but well dispersed and stable in aqueous solution and are globular particles with a range of 35-125 nm in diameter by means of TEM, SEM, AFM and laser sizer. Over one half of the {epsilon}-amino groups exist around the protein nanoparticles by using a trinitrobenzenesulfonic acid (TNBS) method. Raman spectra shows the tyrosine residues on the surface of the globules are more exposed than those on native silk fibers. The crystalline polymorph and conformation transition of the silk nanoparticles from random-coil and {alpha}-helix form (Silk I) into anti-parallel {beta}-sheet form (Silk II) are investigated in detail by using infrared, fluorescence and Raman spectroscopy, DSC, {sup 13}C CP-MAS NMR and electron diffraction. X-ray diffraction of the silk nanoparticles shows that the nanoparticles crystallinity is about four fifths of the native fiber. Our results indicate that the degraded peptide chains of the regenerated silk is gathered homogeneously or heterogeneously to form a looser globular structure in aqueous solution. When introduced into excessive organic solvent, the looser globules of the liquid silk are rapidly dispersed and simultaneously dehydrated internally and externally, resulting in the further chain-chain contact, arrangement of those hydrophobic domains inside the globules and final formation of crystalline silk nanoparticles with {beta}-sheet configuration. The morphology and size of the nanoparticles are relative to the kinds, properties and even molecular structures of organic solvents, and more significantly to the looser globular

Role of Bmznf-2, a Bombyx mori CCCH zinc finger gene, in masculinisation and differential splicing of Bmtra-2.

Science.gov (United States)

Gopinath, Gajula; Arunkumar, Kallare P; Mita, Kazuei; Nagaraju, Javaregowda

2016-08-01

Deciphering the regulatory factors involved in Bombyx mori sex determination has been a puzzle, challenging researchers for nearly a century now. The pre-mRNA of B. mori doublesex (Bmdsx), a master regulator gene of sexual differentiation, is differentially spliced, producing Bmdsxm and Bmdsxf transcripts in males and females respectively. The putative proteins encoded by these differential transcripts orchestrate antagonistic functions, which lead to sexual differentiation. A recent study in B. mori illustrated the role of a W-derived fem piRNA in conferring femaleness. In females, the fem piRNA was shown to suppress the activity of a Z-linked CCCH type zinc finger (znf) gene, Masculiniser (masc), which indirectly promotes the Bmdsxm type of splicing. In this study, we report a novel autosomal (Chr 25) CCCH type znf motif encoding gene Bmznf-2 as one of the potential factors in the Bmdsx sex specific differential splicing, and we also provide insights into its role in the alternative splicing of Bmtra2 by using ovary derived BmN cells. Over-expression of Bmznf-2 induced Bmdsxm type of splicing (masculinisation) with a correspondingly reduced expression of Bmdsxf type isoform in BmN cells. Further, the site-directed mutational studies targeting the tandem CCCH znf motifs revealed their indispensability in the observed phenotype of masculinisation. Additionally, the dual luciferase assays in BmN cells using 5' UTR region of the Bmznf-2 strongly implied the existence of a translational repression over this gene. From these findings, we propose Bmznf-2 to be one of the potential factors of masculinisation similar to Masc. From the growing number of Bmdsx splicing regulators, we assume that the sex determination cascade of B. mori is quite intricate in nature; hence, it has to be further investigated for its comprehensive understanding. Copyright © 2016 Elsevier Ltd. All rights reserved.

2018-02-23T15:33:05Z https://www.ajol.info/index.php/all/oai oai:ojs ...

African Journals Online (AJOL)

article/43127 2018-02-23T15:33:05Z ajb:ART Studies on the quantitative and qualitative characters of cocoons and silk from methoprene and fenoxycarb treated Bombyx mori (L) larvae Mamatha, DM Cohly, HPP Raju, AHH Rao, MR Silkworm, ...

Cloning and identification of an oxytocin/vasopressin-like receptor and its ligand from insects

DEFF Research Database (Denmark)

Stafflinger, Elisabeth; Hansen, Karina K; Hauser, Frank

2008-01-01

holometabolous insect with a completely sequenced genome (12 Drosophila species, the malaria mosquito Anopheles gambiae, the yellow fever mosquito Aedes aegypti, the silk worm Bombyx mori, and the honey bee Apis mellifera), suggesting that this neuropeptide system is confined to basal holometabolous insects...

BM61 of Bombyx mori nucleopolyhedrovirus: its involvement in the egress of nucleocapsids from the nucleus.

Science.gov (United States)

Shen, Hongxing; Chen, Keping

2012-04-05

All lepidopteran baculovirus genomes sequenced encode a homolog of the Bombyx mori nucleopolyhedrovirus orf61 gene (Bm61). To determine the role of Bm61 in the baculoviral life cycle, we constructed a Bm61 knockout virus and characterized it in cells. We observed that the Bm61 deletion bacmid led to a defect in production of infectious budded virus (BV). Quantitative PCR analysis of BV in the media culturing the transfected cell indicated that BV was not produced due to Bm61 deletion. Electron microscope analysis showed that in the knockout of Bm61, nucleocapsids were not transported from the nucleus to the cytoplasm. From these results we concluded that BM61 is required in the BV pathway for the egress of nucleocapsids from the nucleus to the cytoplasm. Copyright © 2012 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.

Precocious metamorphosis in the juvenile hormone-deficient mutant of the silkworm, Bombyx mori.

Directory of Open Access Journals (Sweden)

Takaaki Daimon

Full Text Available Insect molting and metamorphosis are intricately governed by two hormones, ecdysteroids and juvenile hormones (JHs. JHs prevent precocious metamorphosis and allow the larva to undergo multiple rounds of molting until it attains the proper size for metamorphosis. In the silkworm, Bombyx mori, several "moltinism" mutations have been identified that exhibit variations in the number of larval molts; however, none of them have been characterized molecularly. Here we report the identification and characterization of the gene responsible for the dimolting (mod mutant that undergoes precocious metamorphosis with fewer larval-larval molts. We show that the mod mutation results in complete loss of JHs in the larval hemolymph and that the mutant phenotype can be rescued by topical application of a JH analog. We performed positional cloning of mod and found a null mutation in the cytochrome P450 gene CYP15C1 in the mod allele. We also demonstrated that CYP15C1 is specifically expressed in the corpus allatum, an endocrine organ that synthesizes and secretes JHs. Furthermore, a biochemical experiment showed that CYP15C1 epoxidizes farnesoic acid to JH acid in a highly stereospecific manner. Precocious metamorphosis of mod larvae was rescued when the wild-type allele of CYP15C1 was expressed in transgenic mod larvae using the GAL4/UAS system. Our data therefore reveal that CYP15C1 is the gene responsible for the mod mutation and is essential for JH biosynthesis. Remarkably, precocious larval-pupal transition in mod larvae does not occur in the first or second instar, suggesting that authentic epoxidized JHs are not essential in very young larvae of B. mori. Our identification of a JH-deficient mutant in this model insect will lead to a greater understanding of the molecular basis of the hormonal control of development and metamorphosis.

Interactions microsporidies-insectes in vivo : dissémination de Nosema bombycis (Microsporidia) dans son hôte Bombyx mori (Lepidoptera) et caractérisation de protéines structurales majeures de N. bombycis impliquées dans l'invasion

OpenAIRE

Wang, Jian-Yang

2007-01-01

Nosema bombycis is a spore-forming obligate intracellular parasite which belongs to the fungi-related Microsporidia phylum. It is the causative agent of the silkworm Bombyx mori pebrine disease which inflicts severe worldwide economical losses in sericulture. Little is known about N. bombycis in vivo dissemination mechanism and its interactions with its natural host B. mori at the cellular or molecular level, despite the ongoing genome sequencing projects of both organisms. In this study, we ...

Zinc finger protein rotund deficiency affects development of the thoracic leg in Bombyx mori.

Science.gov (United States)

Zhou, Chun-Yan; Zha, Xing-Fu; Liu, Hua-Wei; Xia, Qing-You

2017-06-01

The insect limb develops from the imaginal disc or larval leg during metamorphosis. The molecular mechanisms involved in the development from the larval to the adult leg are poorly understood. Herein, we cloned the full length of a zinc finger gene rotund from Bombyx mori (Bmrn), which contained a 1419 bp open reading frame, and encoded a 473 amino acid protein. Reverse transcription polymerase chain reaction and Western blot analyses demonstrated that Bmrn was expressed at higher levels in the epidermis than in other tissues tested, and it showed a very high expression level during metamorphosis. Knock-down of Bmrn produced defects in the tarsus and pretarsus, including the fusion and reduction of tarsomeres, and the developmental arrest of pretarsus. Our data showed that Bmrn is involved in the formation of the tarsus and pretarsus, whereas its homologous gene in Drosophila has been shown to affect three tarsal segments (t2-t4), suggesting that the remodeling of the leg has involved changes in the patterning of gene regulation during evolution. © 2016 Institute of Zoology, Chinese Academy of Sciences.

Combinatory annotation of cell membrane receptors and signalling pathways of Bombyx mori prothoracic glands

Science.gov (United States)

Moulos, Panagiotis; Samiotaki, Martina; Panayotou, George; Dedos, Skarlatos G.

2016-01-01

The cells of prothoracic glands (PG) are the main site of synthesis and secretion of ecdysteroids, the biochemical products of cholesterol conversion to steroids that shape the morphogenic development of insects. Despite the availability of genome sequences from several insect species and the extensive knowledge of certain signalling pathways that underpin ecdysteroidogenesis, the spectrum of signalling molecules and ecdysteroidogenic cascades is still not fully comprehensive. To fill this gap and obtain the complete list of cell membrane receptors expressed in PG cells, we used combinatory bioinformatic, proteomic and transcriptomic analysis and quantitative PCR to annotate and determine the expression profiles of genes identified as putative cell membrane receptors of the model insect species, Bombyx mori, and subsequently enrich the repertoire of signalling pathways that are present in its PG cells. The genome annotation dataset we report here highlights modules and pathways that may be directly involved in ecdysteroidogenesis and aims to disseminate data and assist other researchers in the discovery of the role of such receptors and their ligands. PMID:27576083

Developmental and sex-specific differences in expression of neuropeptides derived from allatotropin gene in the silkmoth Bombyx mori.

Science.gov (United States)

Bednár, Branislav; Roller, Ladislav; Čižmár, Daniel; Mitrová, Diana; Žitňan, Dušan

2017-05-01

Allatotropin (AT) and related neuropeptides are widespread bioactive molecules that regulate development, food intake and muscle contractions in insects and other invertebrates. In moths, alternative splicing of the at gene generates three mRNA precursors encoding AT with different combinations of three structurally similar AT-like peptides (ATLI-III). We used in situ hybridization and immunohistochemistry to map the differential expression of these transcripts during the postembryonic development of Bombyx mori. Transcript encoding AT alone was expressed in numerous neurons of the central nervous system and frontal ganglion, whereas transcripts encoding AT with ATLs were produced by smaller specific subgroups of neurons in larval stages. Metamorphosis was associated with considerable developmental changes and sex-specific differences in the expression of all transcripts. The most notable was the appearance of AT/ATL transcripts (1) in the brain lateral neurosecretory cells producing prothoracicotropic hormone; (2) in the male-specific cluster of about 20 neurons in the posterior region of the terminal abdominal ganglion; (3) in the female-specific medial neurons in the abdominal ganglia AG2-7. Immunohistochemical staining showed that these neurons produced a mixture of various neuropeptides and innervated diverse peripheral organs. Our data suggest that AT/ATL neuropeptides are involved in multiple stage- and sex-specific functions during the development of B. mori.

Progeny of Palmistichus elaeisis Delvare and LaSalle (Hymenoptera: Eulophidae) parasitising pupae of Bombyx mori L. (Lepidoptera: Bombycidae) of different ages

International Nuclear Information System (INIS)

Pereira, Fabricio F.; Favero, Kellen; Grance, Elizangela L.V.

2009-01-01

Palmistichus elaeisis Delvare and LaSalle is a natural pupal parasitoid of eucalyptus defoliator lepidopterans and is considered a promising biocontrol agent. However, the development of efficient rearing techniques for this natural enemy are fi rst required before it can be used in biocontrol programs. Bombyx mori L. pupae are potential alternative hosts for this parasitoid mass rearing, and they are easy to rear. Therefore, we investigated the most suitable host age and the effects of parasitoid age on progeny production of P. elaeisis. B. mori pupae, 24 h-, 48 h-, 72 h- or 96 h-old were exposed to P. elaeisis females of similar age. The duration of the life cycle (egg-adult) of P. elaeisis was not affected by the age of the parasitizing female; however, the host age affected parasitoid development. The best parasitization was obtained for 72h- to 96h-old parasitoid females when offered to 48h- to 72h-old host pupae, allowing the synchronized rearing of a large number of P. elaeisis offspring. (author)

Genome-wide transcriptional response of silkworm (Bombyx mori to infection by the microsporidian Nosema bombycis.

Directory of Open Access Journals (Sweden)

Zhengang Ma

Full Text Available Microsporidia have attracted much attention because they infect a variety of species ranging from protists to mammals, including immunocompromised patients with AIDS or cancer. Aside from the study on Nosema ceranae, few works have focused on elucidating the mechanism in host response to microsporidia infection. Nosema bombycis is a pathogen of silkworm pébrine that causes great economic losses to the silkworm industry. Detailed understanding of the host (Bombyx mori response to infection by N. bombycis is helpful for prevention of this disease. A genome-wide survey of the gene expression profile at 2, 4, 6 and 8 days post-infection by N. bombycis was performed and results showed that 64, 244, 1,328, 1,887 genes were induced, respectively. Up to 124 genes, which are involved in basal metabolism pathways, were modulated. Notably, B. mori genes that play a role in juvenile hormone synthesis and metabolism pathways were induced, suggesting that the host may accumulate JH as a response to infection. Interestingly, N. bombycis can inhibit the silkworm serine protease cascade melanization pathway in hemolymph, which may be due to the secretion of serpins in the microsporidia. N. bombycis also induced up-regulation of several cellular immune factors, in which CTL11 has been suggested to be involved in both spore recognition and immune signal transduction. Microarray and real-time PCR analysis indicated the activation of silkworm Toll and JAK/STAT pathways. The notable up-regulation of antimicrobial peptides, including gloverins, lebocins and moricins, strongly indicated that antimicrobial peptide defense mechanisms were triggered to resist the invasive microsporidia. An analysis of N. bombycis-specific response factors suggested their important roles in anti-microsporidia defense. Overall, this study primarily provides insight into the potential molecular mechanisms for the host-parasite interaction between B. mori and N. bombycis and may provide a

BNGR-A25L and -A27 are two functional G protein-coupled receptors for CAPA periviscerokinin neuropeptides in the silkworm Bombyx mori.

Science.gov (United States)

Shen, Zhangfei; Chen, Yu; Hong, Lingjuan; Cui, Zhenteng; Yang, Huipeng; He, Xiaobai; Shi, Ying; Shi, Liangen; Han, Feng; Zhou, Naiming

2017-10-06

CAPA peptides, such as periviscerokinin (PVK), are insect neuropeptides involved in many signaling pathways controlling, for example, metabolism, behavior, and reproduction. They are present in a large number of insects and, together with their cognate receptors, are important for research into approaches for improving insect control. However, the CAPA receptors in the silkworm ( Bombyx mori ) insect model are unknown. Here, we cloned cDNAs of two putative CAPA peptide receptor genes, BNGR-A27 and -A25, from the brain of B. mori larvae. We found that the predicted BNGR-A27 ORF encodes 450 amino acids and that one BNGR-A25 splice variant encodes a full-length isoform (BNGR-A25L) of 418 amino acid residues and another a short isoform (BNGR-A25S) of 341 amino acids with a truncated C-terminal tail. Functional assays indicated that both BNGR-A25L and -A27 are activated by the PVK neuropeptides Bom -CAPA-PVK-1 and -PVK-2, leading to a significant increase in cAMP-response element-controlled luciferase activity and Ca 2+ mobilization in a G q inhibitor-sensitive manner. In contrast, BNGR-A25S was not significantly activated in response to the PVK peptides. Moreover, Bom -CAPA-PVK-1 directly bound to BNGR-A25L and -A27, but not BNGR-A25S. Of note, CAPA-PVK-mediated ERK1/2 phosphorylation and receptor internalization confirmed that BNGR-A25L and -A27 are two canonical receptors for Bombyx CAPA-PVKs. However, BNGR-A25S alone is a nonfunctional receptor but serves as a dominant-negative protein for BNGR-A25L. These results provide evidence that BNGR-A25L and -A27 are two functional G q -coupled receptors for Bombyx CAPA-PVKs, enabling the further elucidation of the endocrinological roles of Bom -CAPA-PVKs and their receptors in insect biology. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

Supracolloidal Assemblies as Sacrificial Templates for Porous Silk-Based Biomaterials

Directory of Open Access Journals (Sweden)

John G. Hardy

2015-08-01

Full Text Available Tissues in the body are hierarchically structured composite materials with tissue-specific properties. Urea self-assembles via hydrogen bonding interactions into crystalline supracolloidal assemblies that can be used to impart macroscopic pores to polymer-based tissue scaffolds. In this communication, we explain the solvent interactions governing the solubility of urea and thereby the scope of compatible polymers. We also highlight the role of solvent interactions on the morphology of the resulting supracolloidal crystals. We elucidate the role of polymer-urea interactions on the morphology of the pores in the resulting biomaterials. Finally, we demonstrate that it is possible to use our urea templating methodology to prepare Bombyx mori silk protein-based biomaterials with pores that human dermal fibroblasts respond to by aligning with the long axis of the pores. This methodology has potential for application in a variety of different tissue engineering niches in which cell alignment is observed, including skin, bone, muscle and nerve.

Microscopy based studies on the interaction of bio-based silver nanoparticles with Bombyx mori Nuclear Polyhedrosis virus.

Science.gov (United States)

Tamilselvan, Selvaraj; Ashokkumar, Thirunavukkarasu; Govindaraju, Kasivelu

2017-04-01

In the present investigation, silver nanoparticles (AgNPs) interactions with Bombyx mori Nuclear Polyhedrosis virus (BmNPV) were characterized using High-Resolution Scanning Electron Microscopy (HR-SEM), Energy Dispersive X-ray Analysis (EDAX), Transmission Electron Microscopy (TEM), Atomic Force Microcopy (AFM) and Confocal Microscope (CM). HR-SEM study reveals that the biosynthesized AgNPs have interacted with BmNPV and were found on the surface. TEM micrographs of normal and viral polyhedra treated with AgNPs showed that the nanoparticles were accumulated in the membrane and it was noted that some of the AgNPs successfully penetrated the membrane by reaching the capsid of BmNPV. AFM and confocal microscopy studies reveal that the disruption in the shell membrane tends to lose its stability due to exposure of AgNPs to BmNPV. Copyright © 2017 Elsevier B.V. All rights reserved.

Characterization of Bombyx mori nucleopolyhedrovirus orf68 gene that encodes a novel structural protein of budded virus.

Science.gov (United States)

Iwanaga, Masashi; Kurihara, Masaaki; Kobayashi, Masahiko; Kang, WonKyung

2002-05-25

All lepidopteran baculovirus genomes sequenced to date encode a homolog of the Bombyx mori nucleopolyhedrovirus (BmNPV) orf68 gene, suggesting that it performs an important role in the virus life cycle. In this article we describe the characterization of BmNPV orf68 gene. Northern and Western analyses demonstrated that orf68 gene was expressed as a late gene and encoded a structural protein of budded virus (BV). Immunohistochemical analysis by confocal microscopy showed that ORF68 protein was localized mainly in the nucleus of infected cells. To examine the function of orf68 gene, we constructed orf68 deletion mutant (BmD68) and characterized it in BmN cells and larvae of B. mori. BV production was delayed in BmD68-infected cells. The larval bioassays also demonstrated that deletion of orf68 did not reduce the infectivity, but mutant virus took 70 h longer to kill the host than wild-type BmNPV. In addition, dot-blot analysis showed viral DNA accumulated more slowly in mutant infected cells. Further examination suggested that BmD68 was less efficient in entry and budding from cells, although it seemed to possess normal attachment ability. These results suggest that ORF68 is a BV-associated protein involved in secondary infection from cell-to-cell. (c) 2002 Elsevier Science (USA).

Specific expression of GFPuv-β1,3-N-acetylglucosaminyltransferase 2 fusion protein in fat body of Bombyx mori silkworm larvae using signal peptide

International Nuclear Information System (INIS)

Kato, Tatsuya; Park, Enoch Y.

2007-01-01

Bombyxin (bx) and prophenoloxidase-activating enzyme (ppae) signal peptides from Bombyx mori, their modified signal peptides, and synthetic signal peptides were investigated for the secretion of GFP uv -β1,3-N-acetylglucosaminyltransferase 2 (GGT2) fusion protein in B. mori Bm5 cells and silkworm larvae using cysteine protease deficient B. mori multiple nucleopolyhedrovirus (BmMNPV-CP - ) and its bacmid. The secretion efficiencies of all signal peptides were 15-30% in Bm5 cells and 24-30% in silkworm larvae, while that of the +16 signal peptide was 0% in Bm5 cells and 1% in silkworm larvae. The fusion protein that contained the +16 signal peptide was expressed specifically in the endoplasmic reticulum (ER) and in the fractions of cell precipitations. Ninety-four percent of total intracellular β1,3-N-acetylglucosaminyltransferase (β3GnT) activity was detected in cell precipitations following the 600, 8000, and 114,000g centrifugations. In the case of the +38 signal peptide, 60% of total intracellular activity was detected in the supernatant from the 114,000g spin, and only 1% was found in the precipitate. Our results suggest that the +16 signal peptide might be situated in the transmembrane region and not cleaved by signal peptidase in silkworm or B. mori cells. Therefore, the fusion protein connected to the +16 signal peptide stayed in the fat body of silkworm larvae with biological function, and was not secreted extracellularly

Bombyx mori and Aedes aegypti form multi-functional immune complexes that integrate pattern recognition, melanization, coagulants, and hemocyte recruitment.

Science.gov (United States)

Phillips, Dennis R; Clark, Kevin D

2017-01-01

The innate immune system of insects responds to wounding and pathogens by mobilizing multiple pathways that provide both systemic and localized protection. Key localized responses in hemolymph include melanization, coagulation, and hemocyte encapsulation, which synergistically seal wounds and envelop and destroy pathogens. To be effective, these pathways require a targeted deposition of their components to provide protection without compromising the host. Extensive research has identified a large number of the effectors that comprise these responses, but questions remain regarding their post-translational processing, function, and targeting. Here, we used mass spectrometry to demonstrate the integration of pathogen recognition proteins, coagulants, and melanization components into stable, high-mass, multi-functional Immune Complexes (ICs) in Bombyx mori and Aedes aegypti. Essential proteins common to both include phenoloxidases, apolipophorins, serine protease homologs, and a serine protease that promotes hemocyte recruitment through cytokine activation. Pattern recognition proteins included C-type Lectins in B. mori, while A. aegypti contained a protein homologous to Plasmodium-resistant LRIM1 from Anopheles gambiae. We also found that the B. mori IC is stabilized by extensive transglutaminase-catalyzed cross-linking of multiple components. The melanization inhibitor Egf1.0, from the parasitoid wasp Microplitis demolitor, blocked inclusion of specific components into the IC and also inhibited transglutaminase activity. Our results show how coagulants, melanization components, and hemocytes can be recruited to a wound surface or pathogen, provide insight into the mechanism by which a parasitoid evades this immune response, and suggest that insects as diverse as Lepidoptera and Diptera utilize similar defensive mechanisms.

Assessment of electron beam irradiation induced proteomic changes and its effect on the development of silkworm, Bombyx mori (Bombycidae: Lepidoptera

Directory of Open Access Journals (Sweden)

Mani Kannan

2016-01-01

Full Text Available The present study has been designed to determine the hemolymph protein changes induced by EBI using Microtron (ranges from 20 to 100 Gy on the 5th instar larvae of silkworm, Bombyx mori using SDS–PAGE. The EBI did not caused any impact on 5th instar larval hemolymph proteins, however a significant reduction of pupal hemolymph proteins such as lipophorin (250 kDa, vitellogenin (180 kDa, storage protein (76–80 kDa and a 30 kDa protein was observed through SDS–PAGE and densitometry analysis. These proteins are known to play a crucial role in various developmental processes including transport of lipids, as amino acid reservoir for providing precursors for egg and cuticle formation and immunity of B. mori. Further, a decrease of antioxidant enzymes such as Superoxide Dismutase (SOD and Catalase (CAT in the EBI treated larval and pupal hemolymph was observed. In addition, a negative influence on growth characteristics and appearance of pupal deformity was noted. This may be due to damage in hemolymph proteins, when the larvae were exposed to EBI at >80 Gy.

Surface ultrastructural studies on the germination, penetration and conidial development of Aspergillus flavus Link:Fries infecting silkworm, Bombyx mori Linn.

Science.gov (United States)

Kumar, Vineet; Singh, G P; Babu, A M

2004-01-01

Aspergillosis is a common disease of the silkworm Bombyx mori Linn., caused by an insect mycopathogen Aspergillus flavus Link:Fries. The present study reveals the germination, penetration and conidial development of A. flavus on the larval integument of B. mori under SEM. Four different strains (NB18, KA, NB4D2 and NB7) of B. mori was surface inoculated with ca. of 1 x 10(6) conidia/ml. Each conidium germinated on the cuticle approximately 6 h after inoculation, forming a humpy or suctorial appressoria within 24 h. The hyphae which entered into haemocoel 2 day post-inoculation, grew and multiplied extensively, forming a mycelial complex, causing death of the host larva in about 4-5 days. This occurred with minimal breakdown of the internal tissues. Death of the host was followed by ramification of the fungus through the mesodermal and epidermal tissues, leading to larval mummification about 5-6 days after inoculation. Extensive fungal growths on the entire larval body followed, consisting of aerial hyphae, which developed branched conidiophores. The aerial hyphae with abundant conidiophores formed a confluent yellowish green fungal mat over the entire larval body in 6-7 days of post-inoculation. The tip of each emerging conidiophores gradually dilated and developed to become a bulbous head known as the vesicle. A large number of conidiogenous cells were produced over the entire surface of vesicle, which later developed into finger-like projections termed as sterigmata or phialides. The phialides matured within 2 days after the aerial hyphae emerged as evidenced by chains of conidia at their tips. The conidia were globose with externally roughened walls. The life cycle of the fungus on B. mori was completed in six to seven days.

Silk fibroin membranes from solvent-crystallized silk fibroin/gelatin blends: Effects of blend and solvent composition

Energy Technology Data Exchange (ETDEWEB)

Gil, Eun S. [Fiber and Polymer Science Program, North Carolina State University, Raleigh, NC 27695 (United States); Frankowski, David J. [Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, NC 27695 (United States); Hudson, Samuel M. [Fiber and Polymer Science Program, North Carolina State University, Raleigh, NC 27695 (United States); Spontak, Richard J. [Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, NC 27695 (United States) and Department of Materials Science and Engineering, North Carolina State University, Raleigh, NC 27695 (United States)]. E-mail: Rich_Spontak@ncsu.edu

2007-04-15

Protein membranes have been prepared by mixing gelatin (G) with Bombyx mori silk fibroin (SF) and using aqueous methanol (MeOH) to induce SF crystallization. Amorphous blends of these polymers appear quasi-homogeneous, as discerned from visual observation, electron microscopy and Fourier-transform infrared (FTIR) spectroscopy. Upon subsequent exposure to aqueous MeOH, SF undergoes a conformational change from random-coil to {beta}-sheet. This transformation occurs in pure SF, as well as in each of the G/SF blends, as discerned from FTIR spectroscopy and thermal calorimetry. The influence of MeOH-induced SF crystallization on structure and property development has been measured as functions of blend and solvent composition. By preserving a support scaffold above the G helix-to-coil transition temperature, the formation of crystalline SF networks in G/SF blends can be used to stabilize G-based hydrogels or generate SF membranes for biomaterial, pharmaceutical and gas-separation purposes. The present study not only examines the properties of G/SF blends before and after SF crystallization, but also establishes the foundation for future research into thermally-responsive G/SF bioconjugates.

20-hydroxyecdysone enhances the expression of the chitinase 5 via Broad-Complex Zinc-Finger 4 during metamorphosis in silkworm, Bombyx mori.

Science.gov (United States)

Zhang, X; Zheng, S

2017-04-01

Insect chitinases are hydrolytic enzymes required for the degradation of chitin. They are essential for insect moulting and metamorphosis. In this study, the regulation mechanism of a chitinase gene, Bombyx mori chitinase 5 (BmCHT5), was studied. Quantitative reverse transcription PCR (qRT-PCR) analysis showed that BmCHT5 was up-regulated during the larval-larval and larval-pupa transitions and notably induced by 20-hydroxyecdysone (20E). Analysis of the BmCHT5 promoter revealed the presence of one Bombyx mori Broad-Complex Zinc-Finger Isoform 4 (BR-C Z4), two BR-C Z2 and two ecdysone-induced protein 74A (E74A) cis-regulatory elements (CREs) that are related to 20E. qRT-PCR showed that the expression of both BmBR-C Z4 and BmBR-C Z2 during metamorphosis, and when induced by 20E, was anastomotic with the variations in BmCHT5 mRNA level. In contrast, BmE74A did not follow this trend. An electrophoretic mobility shift assay did not retrieve a binding partner for the two BR-C Z2 CREs in the BmN cell line nuclear extract, whereas BR-C Z4 CRE specifically bound to BmBR-C Z4. Besides, luciferase activity analysis confirmed that BmBR-C Z4 could enhance the activity of the BmCHT5 promoter with BR-C Z4 CRE and could not enhance the promoter activity by mutating BR-C Z4 CRE. Taken together, these data suggest that the transcription factor BmBR-C Z4 enhances the expression of BmCHT5 during metamorphosis. © 2016 The Royal Entomological Society.

RIP-seq of BmAgo2-associated small RNAs reveal various types of small non-coding RNAs in the silkworm, Bombyx mori

Science.gov (United States)

2013-01-01

Background Small non-coding RNAs (ncRNAs) are important regulators of gene expression in eukaryotes. Previously, only microRNAs (miRNAs) and piRNAs have been identified in the silkworm, Bombyx mori. Furthermore, only ncRNAs (50-500nt) of intermediate size have been systematically identified in the silkworm. Results Here, we performed a systematic identification and analysis of small RNAs (18-50nt) associated with the Bombyx mori argonaute2 (BmAgo2) protein. Using RIP-seq, we identified various types of small ncRNAs associated with BmAGO2. These ncRNAs showed a multimodal length distribution, with three peaks at ~20nt, ~27nt and ~33nt, which included tRNA-, transposable element (TE)-, rRNA-, snoRNA- and snRNA-derived small RNAs as well as miRNAs and piRNAs. The tRNA-derived fragments (tRFs) were found at an extremely high abundance and accounted for 69.90% of the BmAgo2-associated small RNAs. Northern blotting confirmed that many tRFs were expressed or up-regulated only in the BmNPV-infected cells, implying that the tRFs play a prominent role by binding to BmAgo2 during BmNPV infection. Additional evidence suggested that there are potential cleavage sites on the D, anti-codon and TψC loops of the tRNAs. TE-derived small RNAs and piRNAs also accounted for a significant proportion of the BmAgo2-associated small RNAs, suggesting that BmAgo2 could be involved in the maintenance of genome stability by suppressing the activities of transposons guided by these small RNAs. Finally, Northern blotting was also used to confirm the Bombyx 5.8 s rRNA-derived small RNAs, demonstrating that various novel small RNAs exist in the silkworm. Conclusions Using an RIP-seq method in combination with Northern blotting, we identified various types of small RNAs associated with the BmAgo2 protein, including tRNA-, TE-, rRNA-, snoRNA- and snRNA-derived small RNAs as well as miRNAs and piRNAs. Our findings provide new clues for future functional studies of the role of small RNAs in insect

Effects of cetyltriethylammonium bromide on the replication of Bombyx mori nucleopolyhedrovirus.

Science.gov (United States)

Zhou, Yajing; Zhang, Zhifang; He, Jialu; Zhang, Yuanxing

2002-05-01

An experimental study was undertaken to quantify the effects of cetyltriethylammonium bromide (CTAB) on the replication of Bombyx mori nucleopolyhedrovirus (BmNPV) and the transcriptionalactivity of BmNPV ie-1 promoter. The results demonstrated that the budded virus (BV) titer rose about 3.7-fold by adding CTAB to the culture media up to 0.1 mu g ml(-1) in infected Bm-N cells with a wild-type BmNPV. The transient expression level of luciferase driven by BmNPV ie-1 promoter was enhanced by more than 3-fold in the presence of 0.1 mu g ml(-1) of CTAB in uninfected insect cells via a transient expression system. Contrary to the rise in BV titer, the polyhedra inside the nucleus of infected cells dropped linearly from 4.0 x 10(6) ml(-1) down to 2.1 x 10(6) ml(-1) with in a range of CTAB concentrations from 0 to 0.25 mu g ml(-1). The same trend in expression level of beta -galactosidase or phytase was given when the Bm-N cells or fifth-instar silkworm larvae infected with a recombinant BmNPV containing the beta -galactosidase or phytase reporter gene driven by the polyhedrin promoter. We deduced that CTAB appeared to affect the virus bi-phasic life cycle stages and production pathways, resulting in an enhancement in BV production and a suppression of occluded virus (OV) production and expression of foreign genes controlled by the polyhedrin promoter.

Efficient silkworm expression of human GPCR (nociceptin receptor) by a Bombyx mori bacmid DNA system

Energy Technology Data Exchange (ETDEWEB)

Kajikawa, Mizuho; Sasaki, Kaori [Medical Institute of Bioregulation, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582 (Japan); Wakimoto, Yoshitaro; Toyooka, Masaru [Department of Chemistry and Chemical Biology, Graduate School of Engineering, Gunma University, 1-5-1 Tenjin-cho, Kiryu, Gunma 376-8515 (Japan); Motohashi, Tomoko; Shimojima, Tsukasa [National Institute of Genetics, 1111 Yata, Mishima, Shizuoka 411-8540 (Japan); Takeda, Shigeki [Department of Chemistry and Chemical Biology, Graduate School of Engineering, Gunma University, 1-5-1 Tenjin-cho, Kiryu, Gunma 376-8515 (Japan); Park, Enoch Y. [Laboratory of Biotechnology, Integrated Bioscience Section, Graduate School of Science and Technology, Shizuoka University, 836 Oya, Suruga-ku, Shizuoka, Shizuoka 422-8529 (Japan); Maenaka, Katsumi, E-mail: kmaenaka-umin@umin.net [Medical Institute of Bioregulation, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582 (Japan)

2009-07-31

Guanine nucleotide-binding protein (G protein) coupled receptors (GPCRs) are frequently expressed by a baculovirus expression vector system (BEVS). We recently established a novel BEVS using the bacmid system of Bombyx mori nucleopolyhedrovirus (BmNPV), which is directly applicable for protein expression in silkworms. Here, we report the first example of GPCR expression in silkworms by the simple injection of BmNPV bacmid DNA. Human nociceptin receptor, an inhibitory GPCR, and its fusion protein with inhibitory G protein alpha subunit (G{sub i}{alpha}) were both successfully expressed in the fat bodies of silkworm larvae as well as in the BmNPV viral fraction. Its yield was much higher than that from Sf9 cells. The microsomal fractions including the nociceptin receptor fusion, which are easily prepared by only centrifugation steps, exhibited [{sup 35}S]GTP{gamma}S-binding activity upon specific stimulation by nociceptin. Therefore, this rapid method is easy-to-use and has a high expression level, and thus will be an important tool for human GPCR production.

Molecular diagnosis for the silk worm Bombyx Mori L. Viral and bacterial diseases in the irradiated and non-irradiated individuals

International Nuclear Information System (INIS)

Abulyazid, I.; Elshafei, A.; El-Said, E.; Mousa, S.; Taha, R.

2007-01-01

Genetic maps for the Bombyx Mori infectious flacherrie virus (BmlFV) causing flacherrie (Fl) disease and nuclear polyhedrosis virus (BmNPV) causing grasserie (Gr) disease were built up in an attempt to diagnose diseases early in young larval stages. For the non-irradiated and irradiated viral RNA of IFV, no amplification was obtained by using RT-PCR and RAPD-PCR techniques. HcoRI, EcoRV, BamHI, Hind III and BamHI restriction enzymes were used to digest the non-irradiated and irradiated viral DNA of BmNPV. It was found that, the two viral DNA samples were genetically different; the similarity indexes were 0.14, 0, 0, 0.18 and 0.15, respectively. At the biochemical level, native protein electrophoresis showed 4 and 3 new proteins in non-irradiated and irradiated Fl diseased larvae, respectively, while Gr diseased larvae showed 1 and 3 new protein types. The similarity index (S.I) between all the tested samples was not exceeded 44%. For lipoprotein pattern, 2 and 3 new lipoprotein types were appeared due to Fl disease in the non-irradiated and irradiated haemolymph samples, respectively, while Gr disease showed 3 new lipoproteins in the non-irradiated samples only. The highest S.I recorded was 56%. Glycoprotein pattern revealed 3 and 5 new glycoprotein types appeared due to Fl disease while Gr disease showed 4 and 6 new types in the non-irradiated and irradiated samples, respectively. The highest S.I was 77%. Fractionated protein with SDS revealed 2 common bands shared between the tested samples with R f values 0.28 and 0.71. Fl disease increased the number of protein bands with the appearance of 5 and 4 new proteins types. Gr disease reduced the total number of proteins with the appearance of 2 and 3 new types. The highest S.I was 59%. Both diseases and irradiation may be mutagenic through the epigenetic level in silkworm larvae leading to death. Thus, the results of the biochemical and genetic characterization of IFV and BmNPV enable us to conclude that the

Physicochemical Properties of Meat Batter Added with Edible Silkworm Pupae (Bombyx mori) and Transglutaminase

Science.gov (United States)

Choi, Yun-Sang

2017-01-01

This study was conducted to investigate the physicochemical properties of meat batters prepared with fresh pork meat, back fat, water, and salt and formulated with three different amounts (5%, 10%, and 15%) of silkworm pupae (Bombyx mori) powder and transglutaminase (TG). Meat batters formulated with silkworm pupae powder showed significantly higher contents of protein and ash than control batter. Addition of silkworm pupae to batter also showed significantly lower cooking loss than the control. Moreover, meat batter containing 15% silkworm pupae showed no significant difference in redness value compared to the control. In addition, pH, viscosity, hardness, gumminess, and chewiness were improved after the addition of silkworm pupae. Furthermore, meat batter formulated with TG and silkworm pupae showed improved hardness, gumminess, chewiness and viscosity compared to control batter. Addition of 1% TG with 15% silkworm pupae to meat batter resulted in significantly higher pH, textures, and viscosity. Our data suggest that both silkworm pupae and TG can be added to meat batter to improve its physicochemical properties. Therefore, combination of silkworm pupae and TG could be a new nutritional and functional source for meat products. PMID:28747820

Antifungal mechanism of antibacterial peptide, ABP-CM4, from Bombyx mori against Aspergillus niger.

Science.gov (United States)

Zhang, Jie; Wu, Xi; Zhang, Shuang-Quan

2008-12-01

Antibacterial peptide, CM4 (ABP-CM4), a 35 amino acid peptide from Chinese silkworm-Bombyx mori, displayed a strong antifungal activity against Aspergillus niger, Trichoderma viride and Gibberella saubinetii. Scanning electron microcopy showed that the morphology of conidia became more irregular and swelled when treated with ABP-CM4 at its minimal inhibitory concentration (MIC) of 8 muM. A cell wall regeneration assay indicated that the plasma membrane was the prime target of ABP-CM4 action. Confocal laser scanning microscopy showed that the cytoskeleton of A. niger was destroyed when treated with ABP-CM4 at 8 muM. Furthermore, transmission electron microscopy showed that the membrane and the cellular organelles of fungus were disrupted and there were many vacuoles in the fungal cellular space after the treatment with ABP-CM4. A gel-retardation assay showed that ABP-CM4 bound the DNA of A. niger. Our results suggest that ABP-CM4 exerts its antifungal activity by disrupting the structure of cell membranes and the cytoskeleton and interacts with the organelles, such as the mitochondrion and with the DNA in the fungal cell, subsequently resulting in cell death.

Dietary TiO2 particles modulate expression of hormone-related genes in Bombyx mori.

Science.gov (United States)

Shi, Guofang; Zhan, Pengfei; Jin, Weiming; Fei, JianMing; Zhao, Lihua

2017-08-01

Silkworm (Bombyx mori) is an economically beneficial insect. Its growth and development are regulated by endogenous hormones. In the present study, we found that feeding titanium dioxide nanoparticles (TiO 2 NP) caused a significant increase of body size. TiO 2 NP stimulated the transcription of several genes, including the insulin-related hormone bombyxin, PI3K/Akt/TOR (where PI3K is phosphatidylinositol 3-kinase and TOR is target of rapamycin), and the adenosine 5'-monophosphateactivated protein kinase (AMPK)/target of rapamycin (TOR) pathways. Differentially expressed gene (DEG) analysis documented 26 developmental hormone signaling related genes that were differentially expressed following dietary TiO 2 NP treatment. qPCR analysis confirmed the upregulation of insulin/ecdysteroid signaling genes, such as bombyxin B-1, bombyxin B-4, bombyxin B-7, MAPK, P70S6K, PI3k, eIF4E, E75, ecdysteroid receptor (EcR), and insulin-related peptide binding protein precursor 2 (IBP2). We infer from the upregulated expression of bombyxins and the signaling network that they act in bombyxin-stimulated ecdysteroidogenesis. © 2017 Wiley Periodicals, Inc.

Physicochemical Properties of Meat Batter Added with Edible Silkworm Pupae (Bombyx mori) and Transglutaminase.

Science.gov (United States)

Park, Yoo-Sun; Choi, Yun-Sang; Hwang, Ko-Eun; Kim, Tae-Kyung; Lee, Cheol-Won; Shin, Dong-Min; Han, Sung Gu

2017-01-01

This study was conducted to investigate the physicochemical properties of meat batters prepared with fresh pork meat, back fat, water, and salt and formulated with three different amounts (5%, 10%, and 15%) of silkworm pupae ( Bombyx mori ) powder and transglutaminase (TG). Meat batters formulated with silkworm pupae powder showed significantly higher contents of protein and ash than control batter. Addition of silkworm pupae to batter also showed significantly lower cooking loss than the control. Moreover, meat batter containing 15% silkworm pupae showed no significant difference in redness value compared to the control. In addition, pH, viscosity, hardness, gumminess, and chewiness were improved after the addition of silkworm pupae. Furthermore, meat batter formulated with TG and silkworm pupae showed improved hardness, gumminess, chewiness and viscosity compared to control batter. Addition of 1% TG with 15% silkworm pupae to meat batter resulted in significantly higher pH, textures, and viscosity. Our data suggest that both silkworm pupae and TG can be added to meat batter to improve its physicochemical properties. Therefore, combination of silkworm pupae and TG could be a new nutritional and functional source for meat products.

Enhancing Effect of Glycerol on the Tensile Properties of Bombyx mori Cocoon Sericin Films

Directory of Open Access Journals (Sweden)

Liangjun Zhu

2011-05-01

Full Text Available An environmental physical method described herein was developed to improve the tensile properties of Bombyx mori cocoon sericin films, by using the plasticizer of glycerol, which has a nontoxic effect compared with other chemical crosslinkers. The changes in the tensile characteristics and the structure of glycerolated (0–40 wt% of glycerol sericin films were investigated. Sericin films, both in dry and wet states, showed enhanced tensile properties, which might be regulated by the addition of different concentrations of glycerol. The introduction of glycerol results in the higher amorphous structure in sericin films as evidenced by analysis of attenuated total reflection Fourier transform infrared (ATR-FTIR spectra, thermogravimetry (TGA and differential scanning calorimetry (DSC curves. Scanning Electron Microscopy (SEM observation revealed that glycerol was homogeneously blended with sericin molecules when its content was 10 wt%, while a small amount of redundant glycerol emerged on the surface of sericin films when its content was increased to 20 wt% or higher. Our results suggest that the introduction of glycerol is a novel nontoxic strategy which can improve the mechanical features of sericin-based materials and subsequently promote the feasibility of its application in tissue engineering.

A clip domain serine protease involved in moulting in the silkworm, Bombyx mori: cloning, characterization, expression patterns and functional analysis.

Science.gov (United States)

Liu, H-W; Wang, L-L; Meng, Z; Tang, X; Li, Y-S; Xia, Q-Y; Zhao, P

2017-10-01

Clip domain serine proteases (CLIPs), characterized by one or more conserved clip domains, are essential components of extracellular signalling cascades in various biological processes, especially in innate immunity and the embryonic development of insects. Additionally, CLIPs may have additional non-immune functions in insect development. In the present study, the clip domain serine protease gene Bombyx mori serine protease 95 (BmSP95), which encodes a 527-residue protein, was cloned from the integument of B. mori. Bioinformatics analysis indicated that BmSP95 is a typical CLIP of the subfamily D and possesses a clip domain at the N terminus, a trypsin-like serine protease (tryp_spc) domain at the C terminus and a conserved proline-rich motif between these two domains. At the transcriptional level, BmSP95 is expressed in the integument during moulting and metamorphosis, and the expression pattern is consistent with the fluctuating 20-hydroxyecdysone (20E) titre in B. mori. At the translational level, BmSP95 protein is synthesized in the epidermal cells, secreted as a zymogen and activated in the moulting fluid. Immunofluorescence revealed that BmSP95 is distributed into the old endocuticle in the moulting stage. The expression of BmSP95 was upregulated by 20E. Moreover, expression of BmSP95 was downregulated by pathogen infection. RNA interference-mediated silencing of BmSP95 led to delayed moulting from pupa to moth. These results suggest that BmSP95 is involved in integument remodelling during moulting and metamorphosis. © 2017 The Royal Entomological Society.

Functional Loss of Bmsei Causes Thermosensitive Epilepsy in Contractile Mutant Silkworm, Bombyx mori

Science.gov (United States)

Nie, Hongyi; Cheng, Tingcai; Huang, Xiaofeng; Zhou, Mengting; Zhang, Yinxia; Dai, Fangyin; Mita, Kazuei; Xia, Qingyou; Liu, Chun

2015-07-01

The thermoprotective mechanisms of insects remain largely unknown. We reported the Bombyx mori contractile (cot) behavioral mutant with thermo-sensitive seizures phenotype. At elevated temperatures, the cot mutant exhibit seizures associated with strong contractions, rolling, vomiting, and a temporary lack of movement. We narrowed a region containing cot to ~268 kb by positional cloning and identified the mutant gene as Bmsei which encoded a potassium channel protein. Bmsei was present in both the cell membrane and cytoplasm in wild-type ganglia but faint in cot. Furthermore, Bmsei was markedly decreased upon high temperature treatment in cot mutant. With the RNAi method and injecting potassium channel blockers, the wild type silkworm was induced the cot phenotype. These results demonstrated that Bmsei was responsible for the cot mutant phenotype and played an important role in thermoprotection in silkworm. Meanwhile, comparative proteomic approach was used to investigate the proteomic differences. The results showed that the protein of Hsp-1 and Tn1 were significantly decreased and increased on protein level in cot mutant after thermo-stimulus, respectively. Our data provide insights into the mechanism of thermoprotection in insect. As cot phenotype closely resembles human epilepsy, cot might be a potential model for the mechanism of epilepsy in future.

Insulin-like growth factor (IGF)-like peptide and 20-hydroxyecdysone regulate the growth and development of the male genital disk through different mechanisms in the silkmoth, Bombyx mori.

Science.gov (United States)

Fujinaga, Daiki; Kohmura, Yusuke; Okamoto, Naoki; Kataoka, Hiroshi; Mizoguchi, Akira

2017-08-01

It is well established that ecdysteroids play pivotal roles in the regulation of insect molting and metamorphosis. However, the mechanisms by which ecdysteroids regulate the growth and development of adult organs after pupation are poorly understood. Recently, we have identified insulin-like growth factor (IGF)-like peptides (IGFLPs), which are secreted after pupation under the control of 20-hydroxyecdysone (20E). In the silkmoth, Bombyx mori, massive amounts of Bombyx-IGFLP (BIGFLP) are present in the hemolymph during pupal-adult development, suggesting its importance in the regulation of adult tissue growth. Thus, we hypothesized that the growth and development of adult tissues including imaginal disks are regulated by the combined effects of BIGFLP and 20E. In this study, we investigated the growth-promoting effects of BIGFLP and 20E using the male genital disks of B. mori cultured ex vivo, and further analyzed the cell signaling pathways mediating hormone actions. We demonstrate that 20E induces the elongation of genital disks, that both hormones stimulate protein synthesis in an additive manner, and that BIGFLP and 20E exert their effects through the insulin/IGF signaling pathway and mitogen-activated protein kinase pathway, respectively. These results show that the growth and development of the genital disk are coordinately regulated by both BIGFLP and 20E. Copyright © 2017 Elsevier Ltd. All rights reserved.

Effects of silk sericin on the proliferation and apoptosis of colon cancer cells

Directory of Open Access Journals (Sweden)

Waraporn Kaewkorn

2012-01-01

Full Text Available Sericin is a silk protein woven from silkworm cocoons (Bombyx mori. In animal model, sericin has been reported to have anti-tumoral action against colon cancer. The mechanisms underlying the activity of sericin against cancer cells are not fully understood. The present study investigated the effects of sericin on human colorectal cancer SW480 cells compared to normal colonic mucosal FHC cells. Since the size of the sericin protein may be important for its activity, two ranges of molecular weight were tested. Sericin was found to decrease SW480 and FHC cell viability. The small sericin had higher anti-proliferative effects than that of the large sericin in both cell types. Increased apoptosis of SW480 cells is associated with increased caspase-3 activity and decreased Bcl-2 expression. The anti-proliferative effect of sericin was accompanied by cell cycle arrest at the S phase. Thus, sericin reduced SW480 cell viability by inducing cell apoptosis via caspase-3 activation and down-regulation of Bcl-2 expression. The present study provides scientific data that support the protective effect of silk sericin against cancer cells of the colon and suggests that this protein may have significant health benefits and could potentially be developed as a dietary supplement for colon cancer prevention.

Bombyx mori nucleopolyhedrovirus ORF54, a viral desmoplakin gene, is associated with the infectivity of budded virions.

Science.gov (United States)

Zhang, Min-Juan; Tian, Cai-Hong; Fan, Xiao-Ying; Lou, Yi-Han; Cheng, Ruo-Lin; Zhang, Chuan-Xi

2012-07-01

Bombyx mori nucleopolyhedrovirus (BmNPV) ORF54 (Bm54), a member of the viral desmoplakin N-terminus superfamily, is homologous to Autographa californica nucleopolyhedrovirus (AcMNPV) ORF66, which is required for the efficient egress of nucleocapsids from the nucleus and occlusion body formation. In this paper, we generated a bacmid with the Bm54 gene deleted via homologous recombination in Escherichia coli and characterized the mutant virus using a transfection-infection assay and transmission electron microscopy analysis. Our results demonstrated that the cells transfected with viral DNA lacking Bm54 produced non-infectious budded viruses (BVs). Electron microscopy showed that although the deletion of Bm54 did not affect assembly and release of nucleocapsids, it severely affected polyhedron formation. In conclusion, deletion of Bm54 resulted in non-infectious BV and defective polyhedra. Although the sequences of Bm54 and Ac66 are very similar, the two genes function quite differently in the regulation of viral life cycle.

Enhancing surface properties of breast implants by using electrospun silk fibroin.

Science.gov (United States)

Valencia-Lazcano, A A; Román-Doval, R; De La Cruz-Burelo, E; Millán-Casarrubias, E J; Rodríguez-Ortega, A

2017-08-24

In the present study, a new electrospun silk fibroin coating of silicone breast implants with improved biocompatibility and mechanical properties was obtained. Fibrous scaffolds were produced by electrospinning a solution containing silk fibroin, derived from Bombyx mori cocoons, and polyethylene oxide (PEO) to be used as a coating of breast implants. A randomly oriented structure of fibroin/PEO was electrospun on implants as assessed by SEM analysis, roughness measurements and ATR-FTIR spectroscopy. The scaffold showed 0.25 µm diameter fibres, 0.76 µm size superficial pores, arithmetic roughness of 0.632 ± 0.12 µm and texture aspect ratio of 0.893 ± 0.04. ATR-FTIR spectroscopy demonstrates the presence of PEO and fibroin in the coating. The mechanical characterisation of the implants before and after being coated with fibroin/PEO demonstrated that the fibroin/PEO scaffold contributes to the increase in the elastic modulus from 0.392 ± 0.02 to 0.560 ± 0.03 MPa and to a more elastic behaviour of the breast implants. Using the fibroin/PEO coating, human fibroblasts seeded on this matrix increased viability up to 30% compared to conventional breast implants. Electrospun silk fibroin could represent a clinically compatible, viable form to coat breast implants. Low cytotoxicity by the fibroin coating and its physico-chemical and mechanical properties may find application in improving breast implants biocompatibility. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2017. © 2017 Wiley Periodicals, Inc.

Molecular and biochemical responses in the midgut of the silkworm, Bombyx mori, infected with Nosema bombycis.

Science.gov (United States)

Li, Zhi; Wang, Yu; Wang, Linling; Zhou, Zeyang

2018-03-06

Microsporidia are a group of eukaryotic intracellular parasites that infect almost all vertebrates and invertebrates. However, there is little information available of how microsporidia obtain nutrients and energy from host cells. The purpose of this study was to investigate the energy and material requirements of Nosema bombycis for the invasion procedure through analyzing the global variation of the gene expression, protein abundance, fatty acids level and ATP flux induced by the microsporidia N. bombycis infection in the midgut of the silkworm Bombyx mori. A suppression subtractive hybridization (SSH) and quantitative real-time PCR (qPCR) analysis were performed to identify the genes upregulated in the midgut of B. mori 48 h following N. bombycis infection. Gene Ontology (GO) and the Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses were used to annotate and summarize the differentially expressed genes, according to the categories 'molecular function', 'cellular component' and 'biological process'. To evaluate the nutrition material and energy costs in B.mori infected by N. bombycis, biochemical analysis was performed to determine the variation of protein abundance, fatty acid levels and ATP flux with or without the microsporidia N. bombycis infection in the midgut of the silkworm B. mori. A total of 744 clones were obtained, 288 clones were randomly selected for sequencing, and 110 unigenes were generated. Amongst these, 49.21%, 30.16% and 14.29% genes were involved in 19 molecular functions, 19 biological processes and nine cellular components, respectively. A total of 11 oxidative phosphorylation- and eight proton-coupled ATP synthesis-related genes were upregulated. Seven protein degradation-, three fat degradation-related genes were upregulated, and no genes related to the de novo synthesis of amino acids and fatty acids were significantly upregulated. The data from the biochemical analysis showed the contents of total protein and ATP of B. mori

Agonist-mediated activation of Bombyx mori diapause hormone receptor signals to extracellular signal-regulated kinases 1 and 2 through Gq-PLC-PKC-dependent cascade.

Science.gov (United States)

Jiang, Xue; Yang, Jingwen; Shen, Zhangfei; Chen, Yajie; Shi, Liangen; Zhou, Naiming

2016-08-01

Diapause is a developmental strategy adopted by insects to survive in challenging environments such as the low temperatures of a winter. This unique process is regulated by diapause hormone (DH), which is a neuropeptide hormone that induces egg diapause in Bombyx mori and is involved in terminating pupal diapause in heliothis moths. An G protein-coupled receptor from the silkworm, B. mori, has been identified as a specific cell surface receptor for DH. However, the detailed information on the DH-DHR system and its mechanism(s) involved in the induction of embryonic diapause remains unknown. Here, we combined functional assays with various specific inhibitors to elucidate the DHR-mediated signaling pathways. Upon activation by DH, B. mori DHR is coupled to the Gq protein, leading to a significant increase of intracellular Ca(2+) and cAMP response element-driven luciferase activity in an UBO-QIC, a specific Gq inhibitor, sensitive manner. B. mori DHR elicited ERK1/2 phosphorylation in a dose- and time-dependent manner in response to DH. This effect was almost completely inhibited by co-incubation with UBO-QIC and was also significantly suppressed by PLC inhibitor U73122, PKC inhibitors Gö6983 and the Ca(2+) chelator EGTA. Moreover, DHR-induced activation of ERK1/2 was significantly attenuated by treatment with the Gβγ specific inhibitors gallein and M119K and the PI3K specific inhibitor Wortmannin, but not by the Src specific inhibitor PP2. Our data also demonstrates that the EGFR-transactivation pathway is not involved in the DHR-mediated ERK1/2 phosphorylation. Future efforts are needed to clarify the role of the ERK1/2 signaling pathway in the DH-mediated induction of B. mori embryonic diapause. Copyright © 2016 Elsevier Ltd. All rights reserved.

Identification, gene expression and immune function of the novel Bm-STAT gene in virus-infected Bombyx mori.

Science.gov (United States)

Zhang, Xiaoli; Guo, Rui; Kumar, Dhiraj; Ma, Huanyan; Liu, Jiabin; Hu, Xiaolong; Cao, Guangli; Xue, Renyu; Gong, Chengliang

2016-02-10

Genes in the signal transducer and activator of transcription (STAT) family are vital for activities including gene expression and immune response. To investigate the functions of the silkworm Bombyx mori STAT (Bm-STAT) gene in antiviral immunity, two Bm-STAT gene isoforms, Bm-STAT-L for long form and Bm-STAT-S for short form, were cloned. Sequencing showed that the open reading frames were 2313 bp encoding 770 amino acid residues for Bm-STAT-L and 2202 bp encoding 734 amino acid residues for Bm-STAT-S. The C-terminal 42 amino acid residues of Bm-STAT-L were different from the last 7 amino acid residues of Bm-STAT-S. Immunofluorescence showed that Bm-STAT was primarily distributed in the nucleus. Transcription levels of Bm-STAT in different tissues were determined by quantitative PCR, and the results revealed Bm-STAT was mainly expressed in testes. Western blots showed two bands with molecular weights of 70 kDa and 130 kDa in testes, but no bands were detected in ovaries by using anti-Bm-STAT antibody as the primary antibody. Expression of Bm-STAT in hemolymph at 48 h post infection with B. mori macula-like virus (BmMLV) was slightly enhanced compared with controls, suggesting a weak response induced by infection with BmMLV. Hemocyte immunofluorescence showed that Bm-STAT expression was elevated in B. mori nucleopolyhedrovirus (BmNPV)-infected cells. Moreover, resistance of BmN cells to BmNPV was reduced by downregulation of Bm-STAT expression and increased by upregulation. Resistance of BmN cells to BmCPV was not significantly improved by upregulating Bm-STAT expression. Therefore, we concluded that Bm-STAT is a newly identified insect gene of the STAT family. The JAK-STAT pathway has a more specialized role in antiviral defense in silkworms, but JAK-STAT pathway is not triggered in response to all viruses. Copyright © 2015 Elsevier B.V. All rights reserved.

Cloning of soluble alkaline phosphatase cDNA and molecular basis of the polymorphic nature in alkaline phosphatase isozymes of Bombyx mori midgut.

Science.gov (United States)

Itoh, M; Kanamori, Y; Takao, M; Eguchi, M

1999-02-01

A cDNA coding for soluble type alkaline phosphatase (sALP) of Bombyx mori was isolated. Deduced amino acid sequence showed high identities to various ALPs and partial similarities to ATPase of Manduca sexta. Using this cDNA sequence as a probe, the molecular basis of electrophoretic polymorphism in sALP and membrane-bound type ALP (mALP) was studied. As for mALP, the result suggested that post-translational modification was important for the proteins to express activity and to represent their extensive polymorphic nature, whereas the magnitude of activities was mainly regulated by transcription. On the other hand, sALP zymogram showed poor polymorphism, but one exception was the null mutant, in which the sALP gene was largely lost. Interestingly, the sALP gene was shown to be transcribed into two mRNAs of different sizes, 2.0 and 2.4 Kb. In addition to the null mutant of sALP, we found a null mutant for mALP. Both of these mutants seem phenotypically silent, suggesting that the functional differentiation between these isozymes is not perfect, so that they can still work mutually and complement each other as an indispensable enzyme for B. mori.

Repair and regeneration of heavy ion beam locally irradiated embryonic hemopoietic organs of silkworm, Bombyx mori

International Nuclear Information System (INIS)

Xu Shiqing; Tu Zhenli

2003-01-01

Eggs of silkworm, Bombyx mori were irradiated by 12 C 5+ ions, at the embryonic wings, where the hemopoietic organs attached. Changes in the development of the silkworm larvae and pupae, especially in the repair and regeneration of the hemopoietic organs represented by their morphological and functional characteristics, were observed. The results showed that the silkworm larvae and pupae developed from the irradiated eggs grew with the physiological obstruction due to exsanguinations, such as difficulty in their metamorphosis and their marked lower survival rates. After 100 Gy irradiation, some of the larvae and pupae died during the periods of larval molting stages, pupation stage and eclosion stage. With increased doses, the deficiencies in the silkworm development became more significant. After 200 Gy irradiation, the average hemocyte density for the 5 th larvae decreased markedly, but the hemocyte density for some individuals were comparable to the control, and regenerated hemopoietic organs was found in these larvae. The results suggested that the silkworm larvae might be capable of self-repair and self-regeneration of the hemopoietic organs after the heave ion irradiation

Stimulation of JNK Phosphorylation by the PTTH in Prothoracic Glands of the Silkworm, Bombyx mori

Directory of Open Access Journals (Sweden)

Shi-Hong Gu

2018-02-01

Full Text Available In this study, phosphorylation of c-Jun N-terminal kinase (JNK by the prothoracicotropic hormone (PTTH was investigated in prothoracic glands (PGs of the silkworm, Bombyx mori. Results showed that JNK phosphorylation was stimulated by the PTTH in time- and dose-dependent manners. In vitro activation of JNK phosphorylation in PGs by the PTTH was also confirmed in an in vivo experiment, in which a PTTH injection greatly increased JNK phosphorylation in PGs of day-6 last instar larvae. JNK phosphorylation caused by PTTH stimulation was greatly inhibited by U73122, a potent and specific inhibitor of phospholipase C (PLC and an increase in JNK phosphorylation was also detected when PGs were treated with agents (either A23187 or thapsigargin that directly elevated the intracellular Ca2+ concentration, thereby indicating involvement of PLC and Ca2+. Pretreatment with an inhibitor (U0126 of mitogen-activated protein kinase (MAPK/extracellular signal-regulated kinase (ERK kinase (MEK and an inhibitor (LY294002 of phosphoinositide 3-kinase (PI3K failed to significantly inhibit PTTH-stimulated JNK phosphorylation, indicating that ERK and PI3K were not related to JNK. We further investigated the effect of modulation of the redox state on JNK phosphorylation. In the presence of either an antioxidant (N-acetylcysteine, NAC or diphenylene iodonium (DPI, PTTH-stimulated JNK phosphorylation was blocked. The JNK kinase inhibitor, SP600125, markedly inhibited PTTH-stimulated JNK phosphorylation and ecdysteroid synthesis. The kinase assay of JNK in PGs confirmed its stimulation by PTTH and inhibition by SP600125. Moreover, PTTH treatment did not affect JNK or Jun mRNA expressions. Based on these findings, we concluded that PTTH stimulates JNK phosphorylation in Ca2+- and PLC-dependent manners and that the redox-regulated JNK signaling pathway is involved in PTTH-stimulated ecdysteroid synthesis in B. mori PGs.

Identification and expression analysis of vitellogenin from silk ...

African Journals Online (AJOL)

user

2011-02-07

Feb 7, 2011 ... Laboratory of Sericulture Sciences, College of Life Sciences, Anhui Agricultural University,130 ... identified from Bombyx mori (Yano et al.,1994a; Yano et ... as follows: 5 min at 94°C; followed by 34 cycles of 94°C for 30 s,.

Phylogenetic relationships of three new microsporidian isolates from the silkworm, Bombyx mori.

Science.gov (United States)

Nageswara Rao, S; Muthulakshmi, M; Kanginakudru, S; Nagaraju, J

2004-07-01

The pathogenicity, mode of transmission, tissue specificity of infection and the small subunit rRNA (SSU-rRNA) gene sequences of the three new microsporidian isolates from the silkworm Bombyx mori were studied. Out of the three, NIK-2r revealed life cycle features and SSU-rRNA gene sequence similar to Nosema bombycis, suggesting that it is N. bombycis. The other two, NIK-4m and NIK-3h, differed from each other as well as from N. bombycis. NIK-4m was highly pathogenic and did not show any vertical transmission, in accordance with the apparent lack of gonadal infection, whereas NIK-3h was less pathogenic and vertical transmission was not detected but could not be excluded. Phylogenetic analysis based on SSU-rRNA gene sequence placed NIK-3h and NIK-4m in a distinct clade that included almost all the Vairimorpha species and Nosema species that infect lepidopteran and non-lepidopteran hosts, while NIK-2r was included in a clade containing almost all the Nosema isolates that infect only lepidopteran hosts. Thus, we have presented molecular evidence that one of the three isolates is in fact the type species N. bombycis, while the other two isolates are Vairimorpha spp. There was distinct separation of microsporidian isolates infecting only lepidopteran hosts and those infecting lepidopteran and non-lepidopteran hosts, reflecting possible co-evolution of hosts and microsporidian isolates.

Journal of Biosciences | Indian Academy of Sciences

Indian Academy of Sciences (India)

We have carried out crystal structure analysis of raw pure Mysore silk fibers belonging to Bombyx mori on the basis of model parameters of Marsh et al using Linked-Atom-Least-Squares technique. The intensity of all the reflections were computed employing CCP13 software. We observe that the molecular modification is ...

Acellular bi-layer silk fibroin scaffolds support tissue regeneration in a rabbit model of onlay urethroplasty.

Science.gov (United States)

Chung, Yeun Goo; Tu, Duong; Franck, Debra; Gil, Eun Seok; Algarrahi, Khalid; Adam, Rosalyn M; Kaplan, David L; Estrada, Carlos R; Mauney, Joshua R

2014-01-01

Acellular scaffolds derived from Bombyx mori silk fibroin were investigated for their ability to support functional tissue regeneration in a rabbit model of urethra repair. A bi-layer silk fibroin matrix was fabricated by a solvent-casting/salt leaching process in combination with silk fibroin film casting to generate porous foams buttressed by homogeneous silk fibroin films. Ventral onlay urethroplasty was performed with silk fibroin grafts (Group 1, N = 4) (Width × Length, 1 × 2 cm(2)) in adult male rabbits for 3 m of implantation. Parallel control groups consisted of animals receiving small intestinal submucosa (SIS) implants (Group 2, N = 4) or urethrotomy alone (Group 3, N = 3). Animals in all groups exhibited 100% survival prior to scheduled euthanasia and achieved voluntary voiding following 7 d of initial catheterization. Retrograde urethrography of each implant group at 3 m post-op revealed wide urethral calibers and preservation of organ continuity similar to pre-operative and urethrotomy controls with no evidence of contrast extravasation, strictures, fistulas, or stone formation. Histological (hematoxylin and eosin and Masson's trichrome), immunohistochemical, and histomorphometric analyses demonstrated that both silk fibroin and SIS scaffolds promoted similar extents of smooth muscle and epithelial tissue regeneration throughout the original defect sites with prominent contractile protein (α-smooth muscle actin and SM22α) and cytokeratin expression, respectively. De novo innervation and vascularization were also evident in all regenerated tissues indicated by synaptophysin-positive neuronal cells and vessels lined with CD31 expressing endothelial cells. Following 3 m post-op, minimal acute inflammatory reactions were elicited by silk fibroin scaffolds characterized by the presence of eosinophil granulocytes while SIS matrices promoted chronic inflammatory responses indicated by mobilization of mononuclear cell infiltrates. The results of this study

Acellular bi-layer silk fibroin scaffolds support tissue regeneration in a rabbit model of onlay urethroplasty.

Directory of Open Access Journals (Sweden)

Yeun Goo Chung

Full Text Available Acellular scaffolds derived from Bombyx mori silk fibroin were investigated for their ability to support functional tissue regeneration in a rabbit model of urethra repair. A bi-layer silk fibroin matrix was fabricated by a solvent-casting/salt leaching process in combination with silk fibroin film casting to generate porous foams buttressed by homogeneous silk fibroin films. Ventral onlay urethroplasty was performed with silk fibroin grafts (Group 1, N = 4 (Width × Length, 1 × 2 cm(2 in adult male rabbits for 3 m of implantation. Parallel control groups consisted of animals receiving small intestinal submucosa (SIS implants (Group 2, N = 4 or urethrotomy alone (Group 3, N = 3. Animals in all groups exhibited 100% survival prior to scheduled euthanasia and achieved voluntary voiding following 7 d of initial catheterization. Retrograde urethrography of each implant group at 3 m post-op revealed wide urethral calibers and preservation of organ continuity similar to pre-operative and urethrotomy controls with no evidence of contrast extravasation, strictures, fistulas, or stone formation. Histological (hematoxylin and eosin and Masson's trichrome, immunohistochemical, and histomorphometric analyses demonstrated that both silk fibroin and SIS scaffolds promoted similar extents of smooth muscle and epithelial tissue regeneration throughout the original defect sites with prominent contractile protein (α-smooth muscle actin and SM22α and cytokeratin expression, respectively. De novo innervation and vascularization were also evident in all regenerated tissues indicated by synaptophysin-positive neuronal cells and vessels lined with CD31 expressing endothelial cells. Following 3 m post-op, minimal acute inflammatory reactions were elicited by silk fibroin scaffolds characterized by the presence of eosinophil granulocytes while SIS matrices promoted chronic inflammatory responses indicated by mobilization of mononuclear cell infiltrates. The results

Induced Hyperproteinemia and Its Effects on the Remodeling of Fat Bodies in Silkworm, Bombyx mori

Science.gov (United States)

Chen, Xue-Dong; Wang, Yong-Feng; Wang, Yu-Long; Li, Qiu-Ying; Ma, Huan-Yu; Wang, Lu; Sima, Yang-Hu; Xu, Shi-Qing

2018-01-01

Hyperproteinemia, which is characterized by an abnormally elevated plasma protein concentration (PPC), is a high-mortality, metabolic complication associated with severe liver and kidney disease. It is difficult to clinically distinguish the difference between the impacts of primary diseases and hyperproteinemia on tissues and organs, and there are no available animal models of hyperproteinemia. Here, we constructed an animal model of hyperproteinemia with a controllable PPC and no primary disease effects in the silkworm Bombyx mori that has attracted interest owing to its potential use in the pathological analysis of model animals. Silkworm have an open circulatory system in which each organ is directly immersed in hemolymph. The fat body (FB) of a silkworm, as a major organ for nutrient storage and energy metabolism, can effectively reflect hyperproteinemia-induced metabolic abnormalities in damaged visceral tissues. A pathogenesis study showed that hyperproteinemia attenuated cell autophagy and apoptosis by attenuating an endocrine hormone, thereby preventing FB remodeling during metamorphosis. Meanwhile, hyperproteinemia increased oxidative stress in the FB and resulted in a dysfunction of amino acid conversion. Supplementation with exogenous 20-hydroxyecdysone effectively mitigated the hyperproteinemia-mediated inhibition of FB remodeling. PMID:29651251

Induced Hyperproteinemia and Its Effects on the Remodeling of Fat Bodies in Silkworm, Bombyx mori

Directory of Open Access Journals (Sweden)

Xue-Dong Chen

2018-03-01

Full Text Available Hyperproteinemia, which is characterized by an abnormally elevated plasma protein concentration (PPC, is a high-mortality, metabolic complication associated with severe liver and kidney disease. It is difficult to clinically distinguish the difference between the impacts of primary diseases and hyperproteinemia on tissues and organs, and there are no available animal models of hyperproteinemia. Here, we constructed an animal model of hyperproteinemia with a controllable PPC and no primary disease effects in the silkworm Bombyx mori that has attracted interest owing to its potential use in the pathological analysis of model animals. Silkworm have an open circulatory system in which each organ is directly immersed in hemolymph. The fat body (FB of a silkworm, as a major organ for nutrient storage and energy metabolism, can effectively reflect hyperproteinemia-induced metabolic abnormalities in damaged visceral tissues. A pathogenesis study showed that hyperproteinemia attenuated cell autophagy and apoptosis by attenuating an endocrine hormone, thereby preventing FB remodeling during metamorphosis. Meanwhile, hyperproteinemia increased oxidative stress in the FB and resulted in a dysfunction of amino acid conversion. Supplementation with exogenous 20-hydroxyecdysone effectively mitigated the hyperproteinemia-mediated inhibition of FB remodeling.

Yorkie Facilitates Organ Growth and Metamorphosis in Bombyx.

Science.gov (United States)

Liu, Shumin; Zhang, Panli; Song, Hong-Sheng; Qi, Hai-Sheng; Wei, Zhao-Jun; Zhang, Guozheng; Zhan, Shuai; Liu, Zhihong; Li, Sheng

2016-01-01

The Hippo pathway, which was identified from genetic screens in the fruit fly, Drosophila melanogaster, has a major size-control function in animals. All key components of the Hippo pathway, including the transcriptional coactivator Yorkie that is the most critical substrate and downstream effector of the Hippo kinase cassette, are found in the silkworm, Bombyx mori. As revealed by microarray and quantitative real-time PCR, expression of Hippo pathway genes is particularly enriched in several mitotic tissues, including the ovary, testis, and wing disc. Developmental profiles of Hippo pathway genes are generally similar (with the exception of Yorkie) within each organ, but vary greatly in different tissues showing nearly opposing expression patterns in the wing disc and the posterior silk gland (PSG) on day 2 of the prepupal stage. Importantly, the reduction of Yorkie expression by RNAi downregulated Yorkie target genes in the ovary, decreased egg number, and delayed larval-pupal-adult metamorphosis. In contrast, baculovirus-mediated Yorkie(CA) overexpression upregulated Yorkie target genes in the PSG, increased PSG size, and accelerated larval-pupal metamorphosis. Together the results show that Yorkie potentially facilitates organ growth and metamorphosis, and suggest that the evolutionarily conserved Hippo pathway is critical for size control, particularly for PSG growth, in the silkworm.

The dynamic landscape of gene regulation during Bombyx mori oogenesis.

Science.gov (United States)

Zhang, Qiang; Sun, Wei; Sun, Bang-Yong; Xiao, Yang; Zhang, Ze

2017-09-11

Oogenesis in the domestic silkworm (Bombyx mori) is a complex process involving previtellogenesis, vitellogenesis and choriogenesis. During this process, follicles show drastic morphological and physiological changes. However, the genome-wide regulatory profiles of gene expression during oogenesis remain to be determined. In this study, we obtained time-series transcriptome data and used these data to reveal the dynamic landscape of gene regulation during oogenesis. A total of 1932 genes were identified to be differentially expressed among different stages, most of which occurred during the transition from late vitellogenesis to early choriogenesis. Using weighted gene co-expression network analysis, we identified six stage-specific gene modules that correspond to multiple regulatory pathways. Strikingly, the biosynthesis pathway of the molting hormone 20-hydroxyecdysone (20E) was enriched in one of the modules. Further analysis showed that the ecdysteroid 20-hydroxylase gene (CYP314A1) of steroidgenesis genes was mainly expressed in previtellogenesis and early vitellogenesis. However, the 20E-inactivated genes, particularly the ecdysteroid 26-hydroxylase encoding gene (Cyp18a1), were highly expressed in late vitellogenesis. These distinct expression patterns between 20E synthesis and catabolism-related genes might ensure the rapid decline of the hormone titer at the transition point from vitellogenesis to choriogenesis. In addition, we compared landscapes of gene regulation between silkworm (Lepidoptera) and fruit fly (Diptera) oogeneses. Our results show that there is some consensus in the modules of gene co-expression during oogenesis in these insects. The data presented in this study provide new insights into the regulatory mechanisms underlying oogenesis in insects with polytrophic meroistic ovaries. The results also provide clues for further investigating the roles of epigenetic reconfiguration and circadian rhythm in insect oogenesis.

Vibration receptive sensilla on the wing margins of the silkworm moth Bombyx mori.

Science.gov (United States)

Ai, Hiroyuki; Yoshida, Akihiro; Yokohari, Fumio

2010-03-01

Bristles along the wing margins (wm-bristles) of the silkworm moth, Bombyx mori, were studied morphologically and electrophysiologically. The male moth has ca. 50 wm-bristles on each forewing and hindwing. Scanning electron microscopy revealed that these wm-bristles are typical mechanosensilla. Leuco-methylene blue staining demonstrated that each wm-bristle has a single receptor neuron, which is also characteristic of the mechanosensillum. The receptor neuron responded to vibrating air currents but did not respond to a constant air current. The wm-bristles showed clear directional sensitivity to vibrating air currents. The wm-bristles were classified into two types, type I and type II, by their response patterns to sinusoidal movements of the bristle. The neuron in type I discharged bursting spikes immediately following stimulation onset and also discharged a single spike for each sinusoidal cycle for frequencies less than ca. 60 Hz. The neuron in type II only responded to vibrations over 40 Hz and, specifically at 75 Hz, discharged a single spike for each sinusoidal cycle throughout the stimulation period. These results suggest that the two types of wm-bristles are highly tuned in different ways to detect vibrations due to the wing beat. The roles of the wm-bristles in the wing beat are discussed. Copyright (c) 2009 Elsevier Ltd. All rights reserved.

Silk I and Silk II studied by fast scanning calorimetry

Energy Technology Data Exchange (ETDEWEB)

Cebe, Peggy; Partlow, Benjamin P.; Kaplan, David L.; Wurm, Andreas; Zhuravlev, Evgeny; Schick, Christoph

2017-06-01

Using fast scanning calorimetry (FSC), we investigated the glass transition and crystal melting of samples of B. mori silk fibroin containing Silk I and/or Silk II crystals. Due to the very short residence times at high temperatures during such measurements, thermal decomposition of silk protein can be significantly suppressed. FSC was performed at 2000 K/s using the Mettler Flash DSC1 on fibroin films with masses around 130–270 ng. Films were prepared with different crystalline fractions (ranging from 0.26 to 0.50) and with different crystal structures (Silk I, Silk II, or mixed) by varying the processing conditions. These included water annealing at different temperatures, exposure to 50% MeOH in water, or autoclaving. The resulting crystal structure was examined using wide angle X-ray scattering. Degree of crystallinity was evaluated from Fourier transform infrared (FTIR) spectroscopy and from analysis of the heat capacity increment at the glass transition temperature. Silk fibroin films prepared by water annealing at 25 °C were the least crystalline and had Silk I structure. FTIR and FSC studies showed that films prepared by autoclaving or 50% MeOH exposure were the most crystalline and had Silk II structure. Intermediate crystalline fraction and mixed Silk I/Silk II structures were found in films prepared by water annealing at 37 °C. FSC results indicate that Silk II crystals exhibit endotherms of narrower width and have higher mean melting temperature Tm(II) = 351 ± 2.6 °C, compared to Silk I crystals which melt at Tm(I) = 292 ± 3.8 °C. Films containing mixed Silk I/Silk II structure showed two clearly separated endothermic peaks. Evidence suggests that the two types of crystals melt separately and do not thermally interconvert on the extremely short time scale (0.065 s between onset and end of melting) of the FSC experiment.

Efficient large-scale protein production of larvae and pupae of silkworm by Bombyx mori nuclear polyhedrosis virus bacmid system

International Nuclear Information System (INIS)

Motohashi, Tomoko; Shimojima, Tsukasa; Fukagawa, Tatsuo; Maenaka, Katsumi; Park, Enoch Y.

2005-01-01

Silkworm is one of the most attractive hosts for large-scale production of eukaryotic proteins as well as recombinant baculoviruses for gene transfer to mammalian cells. The bacmid system of Autographa californica nuclear polyhedrosis virus (AcNPV) has already been established and widely used. However, the AcNPV does not have a potential to infect silkworm. We developed the first practical Bombyx mori nuclear polyhedrosis virus bacmid system directly applicable for the protein expression of silkworm. By using this system, the green fluorescence protein was successfully expressed in silkworm larvae and pupae not only by infection of its recombinant virus but also by direct injection of its bacmid DNA. This method provides the rapid protein production in silkworm as long as 10 days, is free from biohazard, thus will be a powerful tool for the future production factory of recombinant eukaryotic proteins and baculoviruses

教材としてのカイコガ(Bombyx mori) の有用性について

OpenAIRE

花園, 誠; 島田, 聡; 片平, 由紀; 花園, 美樹

2016-01-01

カイコガ(Bombyx mori) は, チョウ目・カイコガ科に属する完全変態の昆虫である. 最近になり「完全人工飼料とカイコ幼虫」のセット購入が年間を通じて可能となり, カイコの飼育は通年化されかつ簡略化された. 本報告では,「４齢・５齢のカイコ」と「完全人工飼料」の教材としての可能性を, 学年縦断的な学習指導案により示す.

Bombyx neuropeptide G protein-coupled receptor A7 is the third cognate receptor for short neuropeptide F from silkworm.

Science.gov (United States)

Ma, Qiang; Cao, Zheng; Yu, Yena; Yan, Lili; Zhang, Wenjuan; Shi, Ying; Zhou, Naiming; Huang, Haishan

2017-12-15

The short neuropeptide F (sNPF) neuropeptides, closely related to vertebrate neuropeptide Y (NPY), have been suggested to exert pleiotropic effects on many physiological processes in insects. In the silkworm ( Bombyx mori ) two orphan G protein-coupled receptors, Bombyx neuropeptide G protein-coupled receptor (BNGR) A10 and A11, have been identified as cognate receptors for sNPFs, but other sNPF receptors and their signaling mechanisms in B. mori remain unknown. Here, we cloned the full-length cDNA of the orphan receptor BNGR-A7 from the brain of B. mori larvae and identified it as a receptor for Bombyx sNPFs. Further characterization of signaling and internalization indicated that BNGR-A7, -A10, and -A11 are activated by direct interaction with synthetic Bombyx sNPF-1 and -3 peptides. This activation inhibited forskolin or adipokinetic hormone-induced adenylyl cyclase activity and intracellular Ca 2+ mobilization via a G i/o -dependent pathway. Upon activation by sNPFs, BNGR-A7, -A10, and -A11 evoked ERK1/2 phosphorylation and underwent internalization. On the basis of these findings, we designated the receptors BNGR-A7, -A10, and -A11 as Bommo -sNPFR-1, -2, and -3, respectively. Moreover, the results obtained with quantitative RT-PCR analysis revealed that the three Bombyx sNPF receptor subtypes exhibit differential spatial and temporal expression patterns, suggesting possible roles of sNPF signaling in the regulation of a wide range of biological processes. Our findings provide the first in-depth information on sNPF signaling for further elucidation of the roles of the Bombyx sNPF/sNPFR system in the regulation of physiological activities. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

Molecular and enzymatic characterization of two enzymes BmPCD and BmDHPR involving in the regeneration pathway of tetrahydrobiopterin from the silkworm Bombyx mori.

Science.gov (United States)

Li, Wentian; Gong, Meixia; Shu, Rui; Li, Xin; Gao, Junshan; Meng, Yan

2015-08-01

Tetrahydrobiopterin (BH4) is an essential cofactor of aromatic amino acid hydroxylases and nitric oxide synthase so that BH4 plays a key role in many biological processes. BH4 deficiency is associated with numerous metabolic syndromes and neuropsychological disorders. BH4 concentration in mammals is maintained through a de novo synthesis pathway and a regeneration pathway. Previous studies showed that the de novo pathway of BH4 is similar between insects and mammals. However, knowledge about the regeneration pathway of BH4 (RPB) is very limited in insects. Several mutants in the silkworm Bombyx mori have been approved to be associated with BH4 deficiency, which are good models to research on the RPB in insects. In this study, homologous genes encoding two enzymes, pterin-4a-carbinolamine dehydratase (PCD) and dihydropteridine reductase (DHPR) involving in RPB have been cloned and identified from B. mori. Enzymatic activity of DHPR was found in the fat body of wild type silkworm larvae. Together with the transcription profiles, it was indicated that BmPcd and BmDhpr might normally act in the RPB of B. mori and the expression of BmDhpr was activated in the brain and sexual glands while BmPcd was expressed in a wider special pattern when the de novo pathway of BH4 was lacked in lemon. Biochemical analyses showed that the recombinant BmDHPR exhibited high enzymatic activity and more suitable parameters to the coenzyme of NADH in vitro. The results in this report give new information about the RPB in B. mori and help in better understanding insect BH4 biosynthetic networks. Copyright © 2015 Elsevier Inc. All rights reserved.

Assessment of bioactivity of cassia fistula using bombyx mori lethality assay

International Nuclear Information System (INIS)

Ashfaq, M.

2009-01-01

In recent times, focus on plant research has increased all over the world and a large body of evidence is being collected to evaluate immense potential of medicinal plants used in various traditional systems. In this regard, the present study was conducted to evaluate the bioactivity of a commonly used medicinal plant Cassia fistula against newly selected Bambyx mori (silkworm) larvae. C. fistula pods were extracted using water, methanol, ethanol, hydro-methanol (1: I) and hydro-ethanol (1: I) and were assayed for their activity against Bambyx mori. Methanol extract of C fistula at concentration of 100 mg/L killed half (LC/sub 50/) of Bamyx mori larvae under study. Bomyx mori LC/sub 50/ for other C. fistula extracts were 400 mg/L for ethanol and hydro-methanol, 800 mg/L for hydro-ethanol and 1600 mg/L for aqueous extract. From the results of the present study it can be concluded that Bambyx mori lethality bioassay can be considered a useful preliminary tool for plant extract toxicity evaluation. The main objectives of the present study was to develop a new and simple assay to evaluate claims from traditional. tribal and advanced medicinal lore to suggest directions for future clinical research and commercial importance that could be carried out by local investigators in developing regions. (author)

The density of females of Palmistichus elaeisis Delvare and LaSalle (Hymenoptera: Eulophidae) affects their reproductive performance on pupae of Bombyx mori L. (Lepidoptera: Bombycidae).

Science.gov (United States)

Pereira, Fabricio F; Zanuncio, José C; Serrão, José E; Zanuncio, Teresinha V; Pratissoli, Dirceu; Pastori, Patrik L

2010-06-01

Palmistichus elaeisis Delvare and LaSalle (Hymenoptera: Eulophidae) is a gregarious and polyphagous parasitoid mainly of Lepidoptera pupae. The objective of this paper as to study the developent of parasitoid on Bombyx mori L. (Lepidoptera: Bombycidae) pupae exposed to one, nine, 18, 27, 36, 45 or 54 female P. elaeisis, respectively. The females of the parasitoid remained in contact with pupae for 24 hours in glass tubes (14.0 x 2.2 cm), packed in a climatic chamber regulated at 25 +/- 2 degrees C, 70 +/- 10% relative humidity and photo phase of 12 hours. With the exception of density 1:1 (72.72%), in other densities parasitism was 100%. Adults of P. elaeisis did not emerge from pupae at densities of 1:1 and 9:1, but 100.0% of parasitoid emergence was observed at the density of 45:1 and 54.54% at 54:1. The duration of the life cycle of this parasitoid ranged from 20 to 28 days. P. elaeisis produced 49 to 589 descendants per pupa of B. mori. The sex ratio of P. elaeisis ranged from 0.93 +/- 0.01 to 0.97 +/- 0.01 without differences with 18, 27, 36, 45 and 54 females/host. This parasitoid should be reared with the density of 45 females per pupa of B. mori.

Comparative Studies of Two-Dimensional Electrophoresis on Galactosidase Relating to Bombyx Lectin Activity

OpenAIRE

加藤, 靖夫; カトウ, ヤスオ; Yasuo, Kato

2005-01-01

"Comparative two-dimensional polyacrylamide gel electrophoresis (2-D PAGE) analysis on the haemolymph of the domesticated silkworm, Bombyx mori and Fraction II obtained by gel filtration from the haemolymph of B. mori was performed using the 2-D mini-slab system (Atto Co.) (the first method of 2-D PAGE) and the Mini-PROTEAN mini tube gel 2-D PAGE system (Bio-Rad Laboratories, Inc.) (the second method). Moreover, two-dimensionnal electrophoresis analysis on standard β-galactosidase, grade III ...

DNA Synthesis during Endomitosis Is Stimulated by Insulin via the PI3K/Akt and TOR Signaling Pathways in the Silk Gland Cells of Bombyx mori

Directory of Open Access Journals (Sweden)

Yaofeng Li

2015-03-01

Full Text Available Silk gland cells undergo multiple endomitotic cell cycles during silkworm larval ontogeny. Our previous study demonstrated that feeding is required for continued endomitosis in the silk gland cells of silkworm larvae. Furthermore, the insulin signaling pathway is closely related to nutritional signals. To investigate whether the insulin signaling pathway is involved in endomitosis in silk gland cells, in this study, we initially analyzed the effects of bovine insulin on DNA synthesis in endomitotic silk gland cells using 5-bromo-2'-deoxyuridine (BrdU labeling technology, and found that bovine insulin can stimulate DNA synthesis. Insulin signal transduction is mainly mediated via phosphoinositide 3-kinase (PI3K/Akt, the target of rapamycin (TOR and the extracellular signal-regulated kinase (ERK pathways in vertebrates. We ascertained that these three pathways are involved in DNA synthesis in endomitotic silk gland cells using specific inhibitors against each pathway. Moreover, we investigated whether these three pathways are involved in insulin-stimulated DNA synthesis in endomitotic silk gland cells, and found that the PI3K/Akt and TOR pathways, but not the ERK pathway, are involved in this process. These results provide an important theoretical foundation for the further investigations of the mechanism underlying efficient endomitosis in silk gland cells.

PEGylated Silk Nanoparticles for Anticancer Drug Delivery

DEFF Research Database (Denmark)

Wongpinyochit, Thidarat; Uhlmann, Petra; Urquhart, Andrew

2015-01-01

Silk has a robust clinical track record and is emerging as a promising biopolymer for drug delivery, including its use as nanomedicine. However, silk-based nanomedicines still require further refinements for full exploitation of their potential; the application of “stealth” design principals...... is especially necessary to support their evolution. The aim of this study was to develop and examine the potential of PEGylated silk nanoparticles as an anticancer drug delivery system. We first generated B. mori derived silk nanoparticles by driving β-sheet assembly (size 104 ± 1.7 nm, zeta potential −56 ± 5.......6 mV) using nanoprecipitation. We then surface grafted polyethylene glycol (PEG) to the fabricated silk nanoparticles and verified the aqueous stability and morphology of the resulting PEGylated silk nanoparticles. We assessed the drug loading and release behavior of these nanoparticles using...

The angiotensin converting enzyme (ACE) inhibitor, captopril disrupts the motility activation of sperm from the silkworm, Bombyx mori.

Science.gov (United States)

Nagaoka, Sumiharu; Kawasaki, Saori; Kawasaki, Hideki; Kamei, Kaeko

2017-11-01

Angiotensin I-converting enzyme (also known as peptidyl dicarboxypeptidase A, ACE, and EC 3.4.15.1), which is found in a wide range of organisms, cleaves C-terminal dipeptides from relatively short oligopeptides. Mammalian ACE plays an important role in the regulation of blood pressure. However, the precise physiological functions of insect ACE homologs have not been understood. As part of our effort to elucidate new physiological roles of insect ACE, we herein report a soluble ACE protein in male reproductive secretions from the silkmoth, Bombyx mori. Seminal vesicle sperm are quiescent in vitro, but vigorous motility is activated by treatment with either a glandula (g.) prostatica homogenate or trypsin in vitro. When seminal vesicle sperm were pre-incubated with captopril, a strong and specific inhibitor of mammalian ACE, and then stimulated to initiate motility by the addition of the g. prostatica homogenate or trypsin, the overall level of acquired motility was reduced in an inhibitor-concentration-dependent manner. In the course of this project, we detected ACE-related carboxypeptidase activity that was inhibited by captopril in both the vesicular (v.) seminalis of the noncopulative male reproductive tract and in the spermatophore that forms in the female bursa copulatrix at the time of mating, just as in an earlier report on the tomato moth, Lacanobia oleracea, which belongs to a different lepidopteran species (Ekbote et al., 2003a). Two distinct genes encoding ACE-like proteins were identified by analysis of B. mori cDNA, and were named BmAcer and BmAcer2, respectively [the former was previously reported by Quan et al. (2001) and the latter was first isolated in this paper]. RT-qPCR and Western blot analyses indicated that the BmAcer2 was predominantly produced in v. seminalis and transferred to the spermatophore during copulation, while the BmAcer was not detected in the adult male reproductive organs. A recombinant protein of BmAcer2 (devoid of a signal

Cloning and homologic analysis of Tpn I gene in silkworm Bombyx ...

African Journals Online (AJOL)

GREGO

2007-03-19

Mar 19, 2007 ... 1Institute of Life Sciences, Jiangsu University, 301 Xuefu Road, Zhenjiang 212013, P. R. China. ... Key words: Tpn I, Bombyx mori, troponin, homology. ... cycles (94ºC for 30 s, 58ºC for 30 s, 72ºC for 3 min) in a Gene Amp.

In vitro study on silk fibroin textile structure for anterior cruciate ligament regeneration.

Science.gov (United States)

Farè, Silvia; Torricelli, Paola; Giavaresi, Gianluca; Bertoldi, Serena; Alessandrino, Antonio; Villa, Tomaso; Fini, Milena; Tanzi, Maria Cristina; Freddi, Giuliano

2013-10-01

A novel hierarchical textile structure made of silk fibroin from Bombyx mori capable of matching the mechanical performance requirements of anterior cruciate ligament (ACL) and in vitro cell ingrowth is described. This sericin-free, Silk Fibroin Knitted Sheath with Braided Core (SF-KSBC) structure was fabricated using available textile technologies. Micro-CT analysis confirmed that the core was highly porous and had a higher degree of interconnectivity than that observed for the sheath. The in vivo cell colonization of the scaffolds is thus expected to penetrate even the internal parts of the structure. Tensile mechanical tests demonstrated a maximum load of 1212.4±56.4 N (under hydrated conditions), confirming the scaffold's suitability for ACL reconstruction. The absence of cytotoxic substances in the extracts of the SF-KSBC structure in culture medium was verified by in vitro tests with L929 fibroblasts. In terms of extracellular matrix production, Human Periodontal Ligament Fibroblasts (HPdLFs) cultured in direct contact with SF-KSBC, compared to control samples, demonstrated an increased secretion of aggrecan (PG) and fibronectin (FBN) at 3 and 7 days of culture, and no change in IL-6 and TNF-α secretion. Altogether, the outcomes of this investigation confirm the significant utility of this novel scaffold for ACL tissue regeneration. Copyright © 2013 Elsevier B.V. All rights reserved.

Bulletin of Materials Science | Indian Academy of Sciences

Indian Academy of Sciences (India)

The present study is concerned with changes of microcrystalline parameters in NB4D2 (Bombyx mori) silk fibres, due to electron irradiation. The irradiation process was performed in air at room temperature using 8 MeV electron beam at different dose rates: 0, 25, 50 and 75 kGy, respectively. X-ray recording of these ...

Determination of the torsion angles of alanine and glycine residues of model compounds of spider silk (AGG){sub 10} using solid-state NMR methods

Energy Technology Data Exchange (ETDEWEB)

Ashida, Jun; Ohgo, Kosuke; Komatsu, Kohei; Kubota, Ayumi; Asakura, Tetsuo [Tokyo University of Agriculture and Technology, Department of Biotechnology (Japan)], E-mail: asakura@cc.tuat.ac.jp

2003-02-15

Spiders synthesize several kinds of silk fibers. In the primary structure of spider silk, one of the major ampullate (dragline, frame) silks, spidroin 1, and flagelliform silk (core fibers of adhesive spiral), there are common repeated X-Gly-Gly (X = Ala, Leu, Pro, Tyr, Glu, and Arg) sequences, which are considered to be related to the elastic character of these fibers. In this paper, two dimensional spin diffusion solid-state NMR under off magic angle spinning (OMAS), {sup 13}C chemical shift contour plots, and Rotational Echo DOuble Resonance (REDOR) were applied to determine the torsion angles of one Ala and two kinds of Gly residues in the Ala-Gly-Gly sequence of {sup 13}C=O isotope-labeled (Ala-Gly-Gly){sub 10}. The torsion angles were determined to be ({phi}, {psi}) = (-90 deg., 150 deg.) within an experimental error of {+-}10 deg. for each residue. This conformation is characterized as 3{sub 1} helix which is in agreement with the structure proposed from the X-ray powder diffraction pattern of poly(Ala-Gly-Gly). The 3{sub 1} helix of (Ala-Gly-Gly){sub 10} does not change by formic acid treatment although (Ala-Gly){sub 15} easily changes from the silk I conformation (the structure of Bombyx mori silk fibroin before spinning in the solid state) to silk II conformation (the structure of the silk fiber after spinning) by such treatment. Thus, the 3{sub 1} helix conformation of (Ala-Gly-Gly){sub 10} is considered very stable. Furthermore, the torsion angles of the 16th Leu residue of (Leu-Gly-Gly){sub 10} were also determined as ({phi}, {psi}) = (-90 deg., 150 deg.) and this peptide is also considered to take 3{sub 1} helix conformation.

Bombyx mori nucleopolyhedrovirus ORF79 is a per os infectivity factor associated with the PIF complex.

Science.gov (United States)

Dong, Zhan-Qi; Zhang, Jun; Chen, Xue-Mei; He, Qian; Cao, Ming-Ya; Wang, La; Li, Hai-Qing; Xiao, Wen-Fu; Pan, Cai-Xia; Lu, Cheng; Pan, Min-Hui

2014-05-12

Bombyx mori nucleopolyhedrovirus (BmNPV) ORF79 (Bm79) encodes an occlusion-derived virus (ODV)-specific envelope protein, which is a homologue of the per os infectivity factor 4 (PIF4) of Autographa californica multiple nucleopolyhedrovirus (AcMNPV). To investigate the role of ORF79 in the BmNPV life cycle, a Bm79 knockout virus (vBm(Bm79KO)) was constructed through homologous recombination in Escherichia coli. Viral DNA replication, budded virus (BV) production and polyhedra formation were unaffected by the absence of BM79. However, results of the larval bioassay demonstrated that the Bm79 deletion resulted in a complete loss of per os infection. Immunofluorescence analysis showed that BM79 localized at the innernuclear membrane of infected cells through its N-terminal sorting motif (SM). Further bimolecular fluorescence protein complementation and co-immunoprecipitation assays demonstrated the interaction of BM79 with PIF1, PIF2, PIF3 and ODV-E66. Thus, BM79 plays an important role in per os infection and is associated with the viral PIF complex of BmNPV. Copyright © 2014 Elsevier B.V. All rights reserved.

20-hydroxyecdysone positively regulates the transcription of the antimicrobial peptide, lebocin, via BmEts and BmBR-C Z4 in the midgut of Bombyx mori during metamorphosis.

Science.gov (United States)

Mai, Taoyi; Chen, Shuna; Lin, Xianyu; Zhang, Xiaojuan; Zou, Xiaopeng; Feng, Qili; Zheng, Sichun

2017-09-01

Metamorphosis is an essential physiological process in insects. This process is triggered by 20-hydroxyecydsone (20E). Lebocin, an antimicrobial peptide of Lepidoptera insects, was significantly up-regulated in the midgut, but not in the fat body of Bombyx mori during metamorphosis. In this study, the expression regulation of lebocin in B. mori midgut was studied. The results showed that B. mori lebocin and its activator BmEts were not responsive to bacterial infection in the midgut, instead, the expression of both genes was up-regulated by 20E treatment. The transcription factor BR-C Z4 in the 20E signal pathway enhanced lebocin promoter activity by directly binding to an upstream cis-response element of the promoter. In the fat body, the mRNA level of B. mori lebocin was decreased when the insect transformed from larval to pupal stage and was increased by immune challenge. The expression profiles of lebocin in Lepidopteran Spodoptera litura was also analyzed and the similar results were observed, S. litura lebocin was significantly up-regulated during midgut regeneration and mainly present in the new-formed intestinal cells of the midgut. All results together suggest that during metamorphosis 20E may activate lebocin expression via BmBR-C Z4 and BmEts in the midgut, where the antimicrobial peptide was produced to protect the midgut from infection. Copyright © 2017 Elsevier Ltd. All rights reserved.

Effects of F virus in Bombyx mori L., 1758 (Lep., bombycidae) and site determination of the viral RNA synthesis by auto-radiography

International Nuclear Information System (INIS)

Almeida, I.M.G. de.

1980-01-01

Some aspects of the pathological process of the infectious flacherie virus in the midgut epithelial cells of the silkworm (Bombyx mori L., 1758 (Lep., Bombycidae)) as well as the site of the viral RNA synthesis were investigated. Electron microscope observation of these inclusion bodies showed that they were surrounded by a single membrane and containing many vesicles and virus particles. The nucleus of the cells infected with the virus exhibited higher electron dense masses than the healthy ones. The site of the viral RNA synthesis. Actinomycin D, at the used concentration, selectively blocked the cell RNA synthesis without affecting the virus RNA synthesis. The inhibition found was about 60%. The data obtained indicated that the viral RNA synthesis occurs in the nucleus of the midgut epithelial cells of the silkworm larvae. (author)

Effects of transient high temperature treatment on the intestinal flora of the silkworm Bombyx mori.

Science.gov (United States)

Sun, Zhenli; Kumar, Dhiraj; Cao, Guangli; Zhu, Liyuan; Liu, Bo; Zhu, Min; Liang, Zi; Kuang, Sulan; Chen, Fei; Feng, Yongjie; Hu, Xiaolong; Xue, Renyu; Gong, Chengliang

2017-06-13

The silkworm Bombyx mori is a poikilotherm and is therefore sensitive to various climatic conditions. The influence of temperature on the intestinal flora and the relationship between the intestinal flora and gene expression in the silkworm remain unknown. In the present study, changes of the intestinal flora at 48, 96 and 144 h following transient high temperature treatment (THTT) of 37 °C for 8 h were investigated. According to principal component analysis, the abundances of Enterococcus and Staphylococcus showed a negative correlation with other dominant genera. After THTT, the gene expression levels of spatzle-1 and dicer-2 were increased and decreased, respectively, which suggested that the Toll and RNAi pathways were activated and suppressed, respectively. The species-gene expression matrix confirmed that the spatzle-1 and dicer-2 gene expression levels were negatively and positively correlated, respectively, with the abundance of Enterococcus and Staphylococcus in the control. The abundance of Variovorax post-THTT was positively correlated with the spatzle-1 gene expression level, whereas the community richness of Enterococcus was negatively correlated with the spatzle-1 gene expression level and positively correlated with the dicer-2. The results of the present investigation provide new evidence for understanding the relationships among THTT, intestinal flora and host gene expression.

Combined toxicity of chlorantraniliprole, lambda-cyhalothrin, and imidacloprid to the silkworm Bombyx mori (Lepidoptera: Bombycidae).

Science.gov (United States)

Liu, Yanmei; Zhang, Hui; He, Fengmei; Li, Xuesheng; Tan, Huihua; Zeng, Dongqiang

2018-05-29

Insecticides with different modes of action may act in combination, in ways such as drifting, spray equipment residual, or utilizing concurrently in mulberry orchards or nearby agricultural fields. Silkworms may suffer from a diverse impact on the survival. In this study, the toxicity of chlorantraniliprole, lambda-cyhalothrin, and imidacloprid and their combinations to the second instar of silkworms (Bombyx mori (L.)(Lepidoptera: Bombycidae)) were evaluated after 48 and 72 h treatment by the leaf-dipping method and the combination index (CI)-isobologram equation. After 48 h treatment, results indicated that (1) the increasing order of toxicity was imidacloprid lambda-cyhalothrin, and that (2) synergism was predominated in most combinations excepted for the lambda-cyhalothrin + imidacloprid combination which displayed an additive effect at f a value 0.5. Then, after 72 h treatment, results exhibited that (1) the increasing order of toxicity was imidacloprid lambda-cyhalothrin < chlorantraniliprole, and that (2) only the chlorantraniliprole + imidacloprid mixture yielded antagonism at f a value 0.5; the other combinations performed an additive effect at least. Consequently, combined toxicity of mixtures may pose a worse effect on silkworm than single toxicity of insecticides. Therefore, we suggest that insecticide mixtures should be added into ecotoxicological risk assessment.

Molecular tracing of white muscardine in the silkworm, Bombyx mori (Linn.) II. Silkworm white muscardine is not caused by artificial release or natural epizootic of Beauveria bassiana in China.

Science.gov (United States)

Chen, Xue; Huang, Cui; He, Lingmin; Zhang, Shengli; Li, Zengzhi

2015-02-01

The fungal pathogen Beauveria bassiana causes serious economic losses in sericulture. Its origin is usually attributed to the release of B. bassiana insecticides against pine caterpillars (Dendrolimus punctuatus). In the present study, 488 B. bassiana isolates obtained from silkworm (Bombyx mori) collected from 13 Chinese provinces, and 327 B. bassiana isolates obtained from D. punctatus collected from 9 provinces, were analyzed for population genetic structure using the ISSR technique based on genetic distance. A UPGMA dendrogram clustered them into three independent clades: two B. mori clades and one D. punctatus clade. A 3-D principal component analysis further divided them into two completely independent host groups, revealing high host-specificity. This suggested that white muscardine occurring in B. mori populations throughout southern China was not caused by any B. bassiana strain either naturally prevailing in D. punctatus populations or by any strain artificially released as a fungal insecticide against D. punctatus. We further investigated the genetic differentiation coefficient Gst and gene flow between B. mori-pathogenic and D. punctatus-pathogenic B. bassiana isolates from across China and from five provinces inhabited by both B. mori and D. punctatus. The Gst value across China was computed as 0.410, while the values of the five provinces ranged from 0.508 to 0.689; all above 0.25, which is the threshold for significant genetic differentiation. This suggests that B. bassiana strains isolated from the two different hosts maintained their respective heredity without a convergent homogenization trend, and reduces the possibility that the host range of the caterpillar isolates could expand and enhance their virulence in B. mori. These findings indicate that the use of B. bassiana does not threaten the safety of sericulture. Copyright © 2014 Elsevier Inc. All rights reserved.

Enhanced osteogenesis of β-tricalcium phosphate reinforced silk fibroin scaffold for bone tissue biofabrication.

Science.gov (United States)

Lee, Dae Hoon; Tripathy, Nirmalya; Shin, Jae Hun; Song, Jeong Eun; Cha, Jae Geun; Min, Kyung Dan; Park, Chan Hum; Khang, Gilson

2017-02-01

Scaffolds, used for tissue regeneration are important to preserve their function and morphology during tissue healing. Especially, scaffolds for bone tissue engineering should have high mechanical properties to endure load of bone. Silk fibroin (SF) from Bombyx mori silk cocoon has potency as a type of biomaterials in the tissue engineering. β-tricalcium phosphate (β-TCP) as a type of bioceramics is also critical as biomaterials for bone regeneration because of its biocompatibility, osteoconductivity, and mechanical strength. The aim of this study was to fabricate three-dimensional SF/β-TCP scaffolds and access its availability for bone grafts through in vitro and in vivo test. The scaffolds were fabricated in each different ratios of SF and β-TCP (100:0, 75:25, 50:50, 25:75). The characterizations of scaffolds were conducted by FT-IR, compressive strength, porosity, and SEM. The in vitro and in vivo tests were carried out by MTT, ALP, RT-PCR, SEM, μ-CT, and histological staining. We found that the SF/β-TCP scaffolds have high mechanical strength and appropriate porosity for bone tissue engineering. The study showed that SF/β-TCP (75:25) scaffold exhibited the highest osteogenesis compared with other scaffolds. The results suggested that SF/β-TCP (75:25) scaffold can be applied as one of potential bone grafts for bone tissue engineering. Copyright © 2016. Published by Elsevier B.V.

Silk fibroin based antibacterial bionanotextiles as wound dressing materials

Energy Technology Data Exchange (ETDEWEB)

Çalamak, Semih [Hacettepe University, Faculty of Pharmacy, Department of Basic Pharmaceutical Sciences, 06100 Ankara (Turkey); Hacettepe University, Department of Nanotechnology and Nanomedicine, 06800 Ankara (Turkey); Erdoğdu, Ceren; Özalp, Meral [Hacettepe University, Faculty of Pharmacy, Department of Pharmaceutical Microbiology, 06100 Ankara (Turkey); Ulubayram, Kezban, E-mail: ukezban@hacettepe.edu.tr [Hacettepe University, Faculty of Pharmacy, Department of Basic Pharmaceutical Sciences, 06100 Ankara (Turkey); Hacettepe University, Department of Nanotechnology and Nanomedicine, 06800 Ankara (Turkey)

2014-10-01

New applications for medical biotextiles have been identified with the development of nanotechnological manufacturing technologies. Combination of nanotechnology and biotextile technology has resulted into a new field called bionanotextiles. Bionanotextiles are used in many areas which include wound dressings, bandages and tissue scaffolds. Silk fibroin (SF) from the cocoon of Bombyx mori, is one of the most favorable wound dressing materials due to its unique properties including biocompatibility, permeability, biodegradability, morphologic flexibility, and proper mechanical properties. The modification of antimicrobial properties of SFs can provide a barrier for bacterial penetration as wound dressing materials. In the present study, antibacterial polyethylenimine (PEI) (10, 20 and 30% (w/w)) was blended with SF and bionanotextiles were successfully fabricated by electrospinning. In addition, silk fibroin nanofibers were also functionalized with sulphate group in order to test whether they exhibit an antibacterial activity or not. Fibroin based bionanotextiles were characterized by scanning electron microscope (SEM), Fourier transform infrared spectroscopy (ATR-FTIR), differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The cytotoxicity evaluations were carried out by L929 fibroblasts with MTT assay. The indirect cytotoxicity results demonstrate that all fibroin and PEI/fibroin extracts have no cytotoxicity on L929 cancer cell line. PEI/fibroin bionanotextiles showed strong antibacterial activities against gram positive Staphylococcus aureus and gram negative Pseudomonas aeruginosa. - Highlights: • Bionanotextiles are combination of nanotechnology and biotextile technology. • Bionanotextiles have good antibacterial activity against both of S. aureus and P. aeruginosa. • Antibacterial bionanotextiles are applicable to most of the infected wounds. • No cytotoxicity was observed on L929 cell line.

Silk fibroin based antibacterial bionanotextiles as wound dressing materials

International Nuclear Information System (INIS)

Çalamak, Semih; Erdoğdu, Ceren; Özalp, Meral; Ulubayram, Kezban

2014-01-01

New applications for medical biotextiles have been identified with the development of nanotechnological manufacturing technologies. Combination of nanotechnology and biotextile technology has resulted into a new field called bionanotextiles. Bionanotextiles are used in many areas which include wound dressings, bandages and tissue scaffolds. Silk fibroin (SF) from the cocoon of Bombyx mori, is one of the most favorable wound dressing materials due to its unique properties including biocompatibility, permeability, biodegradability, morphologic flexibility, and proper mechanical properties. The modification of antimicrobial properties of SFs can provide a barrier for bacterial penetration as wound dressing materials. In the present study, antibacterial polyethylenimine (PEI) (10, 20 and 30% (w/w)) was blended with SF and bionanotextiles were successfully fabricated by electrospinning. In addition, silk fibroin nanofibers were also functionalized with sulphate group in order to test whether they exhibit an antibacterial activity or not. Fibroin based bionanotextiles were characterized by scanning electron microscope (SEM), Fourier transform infrared spectroscopy (ATR-FTIR), differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The cytotoxicity evaluations were carried out by L929 fibroblasts with MTT assay. The indirect cytotoxicity results demonstrate that all fibroin and PEI/fibroin extracts have no cytotoxicity on L929 cancer cell line. PEI/fibroin bionanotextiles showed strong antibacterial activities against gram positive Staphylococcus aureus and gram negative Pseudomonas aeruginosa. - Highlights: • Bionanotextiles are combination of nanotechnology and biotextile technology. • Bionanotextiles have good antibacterial activity against both of S. aureus and P. aeruginosa. • Antibacterial bionanotextiles are applicable to most of the infected wounds. • No cytotoxicity was observed on L929 cell line

Consumption of Bt Rice Pollen Containing Cry1C or Cry2A Protein Poses a Low to Negligible Risk to the Silkworm Bombyx mori (Lepidoptera: Bombyxidae)

Science.gov (United States)

Yang, Yan; Liu, Yue; Cao, Fengqin; Chen, Xiuping; Cheng, Lisheng; Romeis, Jörg; Li, Yunhe; Peng, Yufa

2014-01-01

By consuming mulberry leaves covered with pollen from nearby genetically engineered, insect-resistant rice lines producing Cry proteins derived from Bacillus thuringiensis (Bt), larvae of the domestic silkworm, Bombyx mori (Linnaeus) (Lepidoptera: Bombyxidae), could be exposed to insecticidal proteins. Laboratory experiments were conducted to assess the potential effects of Cry1C- or Cry2A-producing transgenic rice (T1C-19, T2A-1) pollen on B. mori fitness. In a short-term assay, B. mori larvae were fed mulberry leaves covered with different densities of pollen from Bt rice lines or their corresponding near isoline (control) for the first 3 d and then were fed mulberry leaves without pollen. No effect was detected on any life table parameter, even at 1800 pollen grains/cm2 leaf, which is much higher than the mean natural density of rice pollen on leaves of mulberry trees near paddy fields. In a long-term assay, the larvae were fed Bt and control pollen in the same way but for their entire larval stage (approximately 27 d). Bt pollen densities ≥150 grains/cm2 leaf reduced 14-d larval weight, increased larval development time, and reduced adult eclosion rate. ELISA analyses showed that 72.6% of the Cry protein was still detected in the pollen grains excreted with the feces. The low exposure of silkworm larvae to Cry proteins when feeding Bt rice pollen may be the explanation for the relatively low toxicity detected in the current study. Although the results demonstrate that B. mori larvae are sensitive to Cry1C and Cry2A proteins, the exposure levels that harmed the larvae in the current study are far greater than natural exposure levels. We therefore conclude that consumption of Bt rice pollen will pose a low to negligible risk to B. mori. PMID:25014054

Regulation of protein phosphatase 2A during embryonic diapause process in the silkworm, Bombyx mori.

Science.gov (United States)

Gu, Shi-Hong; Hsieh, Hsiao-Yen; Lin, Pei-Ling

2017-11-01

Regulation of protein phosphorylation requires coordinated interactions between protein kinases and protein phosphatases. In the present study, we investigated regulation of protein phosphatase 2A (PP2A) during the embryonic diapause process of B. mori. An immunoblotting analysis showed that Bombyx eggs contained a catalytic C subunit, a major regulatory B subunit (B55/PR55 subunit), and a structural A subunit, with the A and B subunits undergoing differential changes between diapause and non-diapause eggs during embryonic process. In non-diapause eggs, eggs whose diapause initiation was prevented by HCl, and eggs in which diapause had been terminated by chilling of diapausing eggs at 5°C for 70days and then were transferred to 25°C, protein levels of the A and B subunits of PP2A gradually increased toward embryonic development. However, protein levels of the A and B subunits in diapause eggs remained at low levels during the first 8days after oviposition. The direct determination of PP2A enzymatic activity showed that the activity remained at low levels in diapause eggs during the first 8days after oviposition. However, in non-diapause eggs, eggs whose diapause initiation was prevented by HCl, and eggs in which diapause had been terminated by chilling, PP2A enzymatic activity sharply increased during the first several days, reached a peak during the middle embryonic development, and then greatly decreased 3 or 4days before hatching. Examination of temporal changes in mRNA expression levels of the catalytic β subunit and regulatory subunit of PP2A showed high levels in eggs whose diapause initiation was prevented by HCl compared to those in diapause eggs. These results demonstrate that the higher PP2A gene expression and PP2A A and B subunit protein levels and increased enzymatic activity are related to embryonic development of B. mori. Copyright © 2017 Elsevier Ltd. All rights reserved.

Tachykinin-Related Peptides Share a G Protein-Coupled Receptor with Ion Transport Peptide-Like in the Silkworm Bombyx mori.

Directory of Open Access Journals (Sweden)

Chiaki Nagai-Okatani

Full Text Available Recently, we identified an orphan Bombyx mori neuropeptide G protein-coupled receptor (BNGR-A24 as an ion transport peptide-like (ITPL receptor. BNGR-A24 belongs to the same clade as BNGR-A32 and -A33, which were recently identified as natalisin receptors. Since these three BNGRs share high similarities with known receptors for tachykinin-related peptides (TRPs, we examined whether these BNGRs can function as physiological receptors for five endogenous B. mori TRPs (TK-1-5. In a heterologous expression system, BNGR-A24 acted as a receptor for all five TRPs. In contrast, BNGR-A32 responded only to TK-5, and BNGR-A33 did not respond to any of the TRPs. These findings are consistent with recent studies on the ligand preferences for B. mori natalisins. Furthermore, we evaluated whether the binding of ITPL and TRPs to BNGR-A24 is competitive by using a Ca2+ imaging assay. Concomitant addition of a TRP receptor antagonist, spantide I, reduced the responses of BNGR-A24 not only to TK-4 but also to ITPL. The results of a binding assay using fluorescent-labeled BNGR-A24 and ligands demonstrated that the binding of ITPL to BNGR-A24 was inhibited by TK-4 as well as by spantide I, and vice versa. In addition, the ITPL-induced increase in cGMP levels of BNGR-A24-expressing BmN cells was suppressed by the addition of excess TK-4 or spantide I. The intracellular levels of cAMP and cGMP, as second messenger candidates of the TRP signaling, were not altered by the five TRPs, suggesting that these peptides act via different signaling pathways from cAMP and cGMP signaling at least in BmN cells. Taken together, the present findings suggest that ITPL and TRPs are endogenous orthosteric ligands of BNGR-A24 that may activate discrete signaling pathways. This receptor, which shares orthosteric ligands, may constitute an important model for studying ligand-biased signaling.

Protein composition of silk filaments spun under water by caddisfly larvae

Czech Academy of Sciences Publication Activity Database

Yonemura, N.; Sehnal, František; Mita, K.; Tamura, T.

2006-01-01

Roč. 7, č. 12 (2006), s. 3370-3378 ISSN 1525-7797 R&D Projects: GA AV ČR IAA5007402 Institutional research plan: CEZ:AV0Z50070508 Keywords : Bombyx mori Subject RIV: CE - Biochemistry Impact factor: 3.664, year: 2006

Genetic Analysis of Izoenzymes Polymorphisms in Silkworm (Bombyx mori L. Strains - doi: 10.4025/actascibiolsci.v35i2.13102

Directory of Open Access Journals (Sweden)

Maria Aparecida Fernandez

2013-05-01

Full Text Available This work carried out to evaluates the polymorhism in the silkworm of different lineages using the isoenzymes electrophoresis to detect biochemical markers and to investigate the genetics of populations for those lineages. They were used as samples individual extracts of silk glands of second day old larvas of the fifth instar, originating from seven Japanese lineages and eight pure Chinese lineages maintained by the Cocamar-Cooperativa Agroindustrial de Maringá. The isozymes acid phosphatase (ACP, alkaline phosphatase (AKP and carbonic anhydrase (CA they were submitted to the electrophoresis in starch gels 14%. The esterases (EST were analyzed in polyacrylamide gels to 10% and stained with α and b-naphtyl acetate. The total of 21 loci was detected, and 04 (19.05% they are polymorphic, Est-11, Acp, Akp, Ca. The fixation index (Fis for the analyzed isozymes it was 0.0751, indicating excess of homozygotes. The value of Fst (0.6128 it shows that the lineages are well differentiated. The dendrogram obtained with the values of genetic distance didn't separate the Chinese and Japanese lineages analyzed totally. That preliminary evaluation of the lineages of B. mori shows that they present genetic material that it can be used in breeding programs that have the purpose of producing hybrid for silk production.

Correlation between fibroin amino acid sequence and physical silk properties

Czech Academy of Sciences Publication Activity Database

Fedič, Robert; Žurovec, Michal; Sehnal, František

2003-01-01

Roč. 278, č. 37 (2003), s. 35255-35264 ISSN 0021-9258 R&D Projects: GA ČR GA204/00/0019 Institutional research plan: CEZ:AV0Z5007907 Keywords : Bombyx - mori * antheraea-pernyi * messenger-RNA Subject RIV: CE - Biochemistry Impact factor: 6.482, year: 2003

Lipidation of BmAtg8 is required for autophagic degradation of p62 bodies containing ubiquitinated proteins in the silkworm, Bombyx mori.

Science.gov (United States)

Ji, Ming-Ming; Lee, Jae Man; Mon, Hiroaki; Iiyama, Kazuhiro; Tatsuke, Tsuneyuki; Morokuma, Daisuke; Hino, Masato; Yamashita, Mami; Hirata, Kazuma; Kusakabe, Takahiro

2017-10-01

p62/Sequestosome-1 (p62/SQSTM1, hereafter referred to as p62) is a major adaptor that allows ubiquitinated proteins to be degraded by autophagy, and Atg8 homologs are required for p62-mediated autophagic degradation, but their relationship is still not understood in Lepidopteran insects. Here it is clearly demonstrated that the silkworm homolog of mammalian p62, Bombyx mori p62 (Bmp62), forms p62 bodies depending on its Phox and Bem1p (PB1) and ubiquitin-associated (UBA) domains. These two domains are associated with Bmp62 binding to ubiquitinated proteins to form the p62 bodies, and the UBA domain is essential for the binding, but Bmp62 still self-associates without the PB1 or UBA domain. The p62 bodies in Bombyx cells are enclosed by BmAtg9-containing membranes and degraded via autophagy. It is revealed that the interaction between the Bmp62 AIM motif and BmAtg8 is critical for the autophagic degradation of the p62 bodies. Intriguingly, we further demonstrate that lipidation of BmAtg8 is required for the Bmp62-mediated complete degradation of p62 bodies by autophagy. Our results should be useful in future studies of the autophagic mechanism in Lepidopteran insects. Copyright © 2017 Elsevier Ltd. All rights reserved.

Secreted glycoprotein BmApoD1 plays a critical role in anti-oxidation and anti-apoptosis in Bombyx mori.

Science.gov (United States)

Zhou, Yanyan; Wang, Li; Li, Rongqiao; Liu, Minmin; Li, Xiaotong; Su, Hang; Xu, Yusong; Wang, Huabing

2018-01-01

Recent studies highlighted that apolipoprotein D (ApoD) and its homologs exert neuroprotective and antioxidant functions in mammals and Drosophila. Unlike mammals and Drosophila, lepidopteran insects possess three distinct ApoD homologs. However, few information on their functions in lepidopteran insects are available. In this study, we investigated the protective potential of a novel ApoD homolog, BmApoD1, in Bombyx mori. Quantitative PCR analyses demonstrated that BmApoD1 is extensively expressed at low levels during the larval stage but abundantly expressed in the testis during the pupal and adult stages. Tryptophan fluorescence titration demonstrated that recombinant BmApoD1 protein can bind retinoic acid and ergosterol. In addition, we provided evidence that N-linked glycans of BmApoD1 are essential to BmApoD1 secretion, and three residues, namely, Asp69, Asp104, and Asp196, are the glycosylation sites of BmApoD1. Furthermore, we showed that BmApoD1 is significantly up-regulated in the larvae after oxidant or starvation treatment. The recombinant BmApoD1 protein can protect cells from oxidative stress induced by H 2 O 2 and reduce actinomycin D-induced cell apoptosis. These observations, together with the transcriptional up-regulation of BmApoD1 in several tissues upon oxidative insult, identify BmApoD1 as a potent antioxidant. Our results demonstrate that BmApoD1 is critical for metabolic adaptation of B. mori to environmental challenges. Copyright © 2017 Elsevier Inc. All rights reserved.

Influence of Bakuchiol, a JH analogue from Bemchi ( Psoralea ...

African Journals Online (AJOL)

The influence of a juvenile hormone analogue (JHA), bakuchiol on the silk yield of silkworm, Bombyx mori L. was studied involving two popular commercial hybrids, KA x NB4D2 (bivoltine x bivoltine) and PM x NB4D2 (multivoltine x bivoltine). The compound was administered topically to 5th instars at 24, 48, 72 and 96 h as ...

Insulin and 20-hydroxyecdysone action in Bombyx mori: Glycogen content and expression pattern of insulin and ecdysone receptors in fat body.

Science.gov (United States)

Keshan, Bela; Thounaojam, Bembem; Kh, Sanathoibi D

2017-01-15

Insulin and ecdysone signaling play a critical role on the growth and development of insects including Bombyx mori. Our previous study showed that Bombyx larvae reached critical weight for metamorphosis between day 3.5 and 4 of the fifth larval instar. The present study showed that the effect of insulin on the accumulation of glycogen in fat body of Bombyx larvae depends on the critical growth period. When larvae are in active growth period (before reaching critical weight), insulin caused increased accumulation of glycogen, while its treatment in larvae at terminal growth period (after critical period) resulted in an increased mobilization of glycogen. During terminal growth period, insulin and 20-hydroxyecdysone (20E) showed an antagonistic effect on the accumulation of fat body glycogen in fed, food deprived and decapitated larvae as well as in isolated abdomens. Insulin treatment decreased the glycogen content, whereas, 20E increased it. Food deprivation and decapitation caused an increase in the transcript levels of insulin receptor (InR) and this increase in InR expression might be attributed to a decrease in synthesis/secretion of insulin-like peptides, as insulin treatment in these larvae showed a down-regulation in InR expression. However, insulin showed an up-regulation in InR in isolated abdomens and it suggests that in food deprived and decapitated larvae, the exogenous insulin may interact with some head and/or thoracic factors in modulating the expression of InR. Moreover, in fed larvae, insulin-mediated increase in InR expression indicates that its regulation by insulin-like peptides also depends on the nutritional status of the larvae. The treatment of 20E in fed larvae showed an antagonistic effect on the transcript levels since a down-regulation in InR expression was observed. 20E treatment also led to a decreased expression of InR in food deprived and decapitated larvae as well as in isolated abdomens. Insulin and 20E also modulated the

The BRO proteins of Bombyx mori nucleopolyhedrovirus are nucleocytoplasmic shuttling proteins that utilize the CRM1-mediated nuclear export pathway

International Nuclear Information System (INIS)

Kang, Won Kyung; Kurihara, Masaaki; Matsumoto, Shogo

2006-01-01

The BRO proteins of Bombyx mori nucleopolyhedrovirus (BmNPV) display a biphasic pattern of intracellular localization during infection. At early times, they reside in the nucleus but then show both cytoplasmic and nuclear localization as the infection proceeds. Therefore, we examined the possibility of nuclear export. Using inhibitors, we reveal that BmNPV BRO proteins shuttle between the nucleus and cytoplasm. Mutations on the leucine-rich region of BRO proteins resulted in nuclear accumulation of transiently expressed proteins, suggesting that this region functions as a CRM1-dependent nuclear export signal (NES). On the contrary, mutant BRO-D with an altered NES did not show nuclear accumulation in infected cells, although protein production seemed to be reduced. RT-PCR analysis showed that the lower level of protein production was due to a reduction in RNA synthesis. Taken together, our results suggest that BRO proteins are nucleocytoplasmic shuttling proteins that utilize the CRM1-mediated nuclear export pathway

EST Table: NM_001111334 [KAIKOcDNA[Archive

Lifescience Database Archive (English)

Full Text Available NM_001111334 Br-c 10/09/29 81 %/420 aa ref|NP_001104804.1| broad-complex isoform Z1... [Bombyx mori] dbj|BAD23978.1| broad-complex Z1-isoform [Bombyx mori] dbj|BAD23983.1| broad-complex Z1-isofo...rm [Bombyx mori] dbj|BAD24045.1| Broad-Complex isoform Z1 [Bombyx mori] dbj|BAD24046.1| Broad-Complex isofor...m Z1 [Bombyx mori] dbj|BAD46732.1| broad-complex A-Z1 isoform [Bombyx mori] dbj|BAD46739.1| broad...-complex B-Z1 isoform [Bombyx mori] dbj|BAF43564.1| Broad-Complex isoform Z1 [Bombyx mori] 1

Production Efficiency of Cocoon Shell of Silkworm, Bombyx mori L. (Bombycidae: Lepidoptera, as an Index for Evaluating the Nutritive Value of Mulberry, Morus sp. (Moraceae, Varieties

Directory of Open Access Journals (Sweden)

Jalaja Suresh Kumar

2011-01-01

Full Text Available The nutritional efficiency of mulberry leaves consumed by silkworms, Bombyx mori L., is usually evaluated in terms of the proportion of cocoon shell weight to the amount of food ingested. The production efficiency of cocoon shell is generally used to identify the superiority of a mulberry variety for silkworm rearing. In this study the production efficiency of cocoon shell was used as an index for evaluating the nutritive value of different mulberry varieties of India. Among the varieties, V-1, having highest production efficiency of cocoon shell with less amount of food ingested and highest digestibility, is regarded as the best suitable variety with nutritive values ideal for silkworm rearing.

Cloning and homologic analysis of Tpn I gene in silkworm Bombyx ...

African Journals Online (AJOL)

Cloning and homologic analysis of Tpn I gene in silkworm Bombyx mori. Y Zhao, Yao Q, X Tang, Q Wang, H Yin, Z Hu, J Lu, K Chen. Abstract. The troponin complex is composed of three subunits, Troponin C (the calcium sensor component) and Troponin T and I (structural proteins). Tpn C is encoded by multiple genes in ...

Appearance of differentiated cells derived from polar body nuclei in the silkworm, Bombyx mori

Directory of Open Access Journals (Sweden)

Hiroki eSakai

2013-09-01

Full Text Available AbstractIn Bombyx mori, polar body nuclei are observed until 9h after egg lying, however, the fate of polar body nuclei remains unclear. To examine the fate of polar body nuclei, we employed a mutation of serosal cell pigmentation, pink-eyed white egg (pe. The heterozygous pe/+pe females produced black serosal cells in white eggs, while pe/pe females did not produce black serosal cells in white eggs. These results suggest that the appearance of black serosal cells in white eggs depends on the genotype (pe/ +pe of the mother. Because the polar body nuclei had +pe genes in the white eggs laid by a pe/ +pe female, polar body nuclei participate in development and differentiate into functional cell (serosal cells. Analyses of serosal cells pigmentation indicated that approximately 30% of the eggs contained polar-body-nucleus-derived cells. These results demonstrate that polar-body-nucleus-derived cells appeared at a high frequency under natural conditions. Approximately 80% of polar-body-nucleus-derived cells appeared near the anterior pole and the dorsal side, which is opposite to where embryogenesis occurs. The number of cells derived from the polar body nuclei was very low. Approximately 26 % of these eggs contained only one black serosal cell. PCR-based analysis revealed that the polar-body-nucleus-derived cells disappeared in late embryonic stages (stage 25. Overall, polar-body-nuclei-derived cells were unlikely to contribute to embryos.

Genetic characterization of Bombyx mori (Lepidoptera: Bombycidae) breeding and hybrid lines with different geographic origins.

Science.gov (United States)

Furdui, Emilia M; Mărghitaş, Liviu A; Dezmirean, Daniel S; Paşca, Ioan; Pop, Iulia F; Erler, Silvio; Schlüns, Ellen A

2014-01-01

The domesticated silkworm Bombyx mori L. comprises a large number of geographical breeds and hybrid lines. Knowing the genetic structure of those may provide information to improve the conservation of commercial lines by estimating inbreeding over generations and the consequences of excessive use of those lineages. Here, we analyzed the genetic diversity of seven breeds and eight hybrid lines from Eastern Europe and Asia using highly polymorphic microsatellites markers to determine its genetical impact on their use in global breeding programs. No consistent pattern of deviation from Hardy-Weinberg equilibrium was found for most breed and hybrids; and the absence of a linkage disequilibrium also suggests that the strains are in equilibrium. A principal coordinate analysis revealed a clear separation of two silkworm breeds from the rest: one (IBV) originated from India and the other one (RG90) from Romania/Japan. The tendency of the other breeds from different geographic origins to cluster together in a general mix might be due to similar selection pressures (climate and anthropogenic factors) in different geographic locations. Phylogenetic analyses grouped the different silkworm breeds but not the hybrids according to their geographic origin and confirmed the pattern found in the principal coordinate analysis. © The Author 2014. Published by Oxford University Press on behalf of the Entomological Society of America.

The Expression, Purification, and Characterization of a Ras Oncogene (Bras2 in Silkworm (Bombyx mori

Directory of Open Access Journals (Sweden)

Zhengbing Lv

2013-01-01

Full Text Available The Ras oncogene of silkworm pupae (Bras2 may belong to the Ras superfamily. It shares 77% of its amino acid identity with teratocarcinoma oncogene 21 (TC21 related ras viral oncogene homolog-2 (R-Ras2 and possesses an identical core effector region. The mRNA of Bombyx mori Bras2 has 1412 bp. The open reading frame contains 603 bp, which encodes 200 amino acid residues. This recombinant BmBras2 protein was subsequently used as an antigen to raise a rabbit polyclonal antibody. Western blotting and real-time PCR analyses showed that BmBras2 was expressed during four developmental stages. The BmBras2 expression level was the highest in the pupae and was low in other life cycle stages. BmBras2 was expressed in all eight tested tissues, and it was highly expressed in the head, intestine, and epidermis. Subcellular localization studies indicated that BmBras2 was predominantly localized in the nuclei of Bm5 cells, although cytoplasmic staining was also observed to a lesser extent. A cell proliferation assay showed that rBmBras2 could stimulate the proliferation of hepatoma cells. The higher BmBras2 expression levels in the pupal stage, tissue expression patterns, and a cell proliferation assay indicated that BmBras2 promotes cell division and proliferation, most likely by influencing cell signal transduction.

The Expression, Purification, and Characterization of a Ras Oncogene (Bras2) in Silkworm (Bombyx mori).

Science.gov (United States)

Lv, Zhengbing; Wang, Tao; Zhuang, Wenhua; Wang, Dan; Chen, Jian; Nie, Zuoming; Liu, Lili; Zhang, Wenping; Wang, Lisha; Wang, Deming; Wu, Xiangfu; Li, Jun; Qian, Lian; Zhang, Yaozhou

2013-01-01

The Ras oncogene of silkworm pupae (Bras2) may belong to the Ras superfamily. It shares 77% of its amino acid identity with teratocarcinoma oncogene 21 (TC21) related ras viral oncogene homolog-2 (R-Ras2) and possesses an identical core effector region. The mRNA of Bombyx mori Bras2 has 1412 bp. The open reading frame contains 603 bp, which encodes 200 amino acid residues. This recombinant BmBras2 protein was subsequently used as an antigen to raise a rabbit polyclonal antibody. Western blotting and real-time PCR analyses showed that BmBras2 was expressed during four developmental stages. The BmBras2 expression level was the highest in the pupae and was low in other life cycle stages. BmBras2 was expressed in all eight tested tissues, and it was highly expressed in the head, intestine, and epidermis. Subcellular localization studies indicated that BmBras2 was predominantly localized in the nuclei of Bm5 cells, although cytoplasmic staining was also observed to a lesser extent. A cell proliferation assay showed that rBmBras2 could stimulate the proliferation of hepatoma cells. The higher BmBras2 expression levels in the pupal stage, tissue expression patterns, and a cell proliferation assay indicated that BmBras2 promotes cell division and proliferation, most likely by influencing cell signal transduction.

Impact of silk fibroin-based scaffold structures on human osteoblast MG63 cell attachment and proliferation

Directory of Open Access Journals (Sweden)

Varkey A

2015-10-01

Full Text Available Aneesia Varkey,1,2 Elakkiya Venugopal,2 Ponjanani Sugumaran,2 Gopinathan Janarthanan,1 Mamatha M Pillai,2 Selvakumar Rajendran,2 Amitava Bhattacharyya1 1Advanced Textile and Polymer Research Laboratory, 2Tissue Engineering Laboratory, PSG Institute of Advanced Studies, Coimbatore, Tamil Nadu, India Abstract: The present study was carried out to investigate the impact of various types of silk fibroin (SF scaffolds on human osteoblast-like cell (MG63 attachment and proliferation. SF was isolated from Bombyx mori silk worm cocoons after degumming. Protein concentration in the degummed SF solution was estimated using Bradford method. Aqueous SF solution was used to fabricate three different types of scaffolds, viz, electrospun nanofiber mat, sponge, and porous film. The structures of the prepared scaffolds were characterized using optical micro­scopy and field emission scanning electron microscopy. The changes in the secondary structure of the proteins and the thermal behavior of the scaffolds were determined by Fourier transform infrared spectroscopy and thermo-gravimetric analysis, respectively. The biodegradation rate of scaffolds was determined by incubating the scaffolds in simulated body fluid for 4 weeks. MG63 cells were seeded on the scaffolds and their attachment and proliferation onto the scaffolds were studied. The MTT assay was carried out to deduce the toxicity of the developed scaffolds. All the scaffolds were found to be biocompatible. The amount of collagen produced by the osteoblast-like cells growing on different scaffolds was estimated. Keywords: silk fibroin scaffold, electrospun nanofiber, porous film, sponge, osteoblast

Abortive replication of Bombyx mori nucleopolyhedrovirus in Sf9 and High Five cells: Defective nuclear transport of the virions

International Nuclear Information System (INIS)

Katou, Yasuhiro; Ikeda, Motoko; Kobayashi, Michihiro

2006-01-01

Despite close genetic relationship, Bombyx mori nucleopolyhedrovirus (BmNPV) and Autographa californica multicapsid NPV (AcMNPV) display a distinct host range property. Here, BmNPV replication was examined in Sf9 and High Five cells that were nonproductive for BmNPV infection but supported high titers of AcMNPV replication. Recombinant BmNPV, vBm/gfp/lac, containing bm-ie1 promoter-driven egfp showed that few Sf9 and High Five cells infected with vBm/gfp/lac expressed EGFP, while large proportion of EGFP-expressing cells was observed when transfected with vBm/gfp/lac DNA. Immunocytochemical analysis showed that BmNPV was not imported into the nucleus of these two cell lines, while recombinant BmNPV, vBmΔ64/ac-gp64 possessing AcMNPV gp64 was imported into the nucleus, yielding progeny virions in High Five cells, but not Sf9 cells. These results indicate that the defective nuclear import of infected virions due to insufficient BmNPV GP64 function is involved in the restricted BmNPV replication in Sf9 and High Five cells

BmCyclin B and BmCyclin B3 are required for cell cycle progression in the silkworm, Bombyx mori.

Science.gov (United States)

Pan, Minhui; Hong, Kaili; Chen, Xiangyun; Pan, Chun; Chen, Xuemei; Kuang, Xiuxiu; Lu, Cheng

2013-04-01

Cyclin B is an important regulator of the cell cycle G2 to M phase transition. The silkworm genomic database shows that there are two Cyclin B genes in the silkworm (Bombyx mori), BmCyclin B and BmCyclin B3. Using silkworm EST data, the cyclin B3 (EU074796) gene was cloned. Its complete cDNA was 1665 bp with an ORF of 1536 bp derived from seven exons and six introns. The BmCyclin B3 gene encodes 511 amino acids, and the predicted molecular weight is 57.8 kD with an isoelectric point of 9.18. The protein contains one protein damage box and two cyclin boxes. RNA interference-mediated reduction of BmCyclin B and BmCyclin B3 expression induced cell cycle arrest in G2 or M phase in BmN-SWU1 cells, thus inhibiting cell proliferation. These results suggest that BmCyclin B and BmCyclin B3 are necessary for completing the cell cycle in silkworm cells.

Correlation between fibroin amino acid sequence and physical silk properties.

Science.gov (United States)

Fedic, Robert; Zurovec, Michal; Sehnal, Frantisek

2003-09-12

The fiber properties of lepidopteran silk depend on the amino acid repeats that interact during H-fibroin polymerization. The aim of our research was to relate repeat composition to insect biology and fiber strength. Representative regions of the H-fibroin genes were sequenced and analyzed in three pyralid species: wax moth (Galleria mellonella), European flour moth (Ephestia kuehniella), and Indian meal moth (Plodia interpunctella). The amino acid repeats are species-specific, evidently a diversification of an ancestral region of 43 residues, and include three types of regularly dispersed motifs: modifications of GSSAASAA sequence, stretches of tripeptides GXZ where X and Z represent bulky residues, and sequences similar to PVIVIEE. No concatenations of GX dipeptide or alanine, which are typical for Bombyx silkworms and Antheraea silk moths, respectively, were found. Despite different repeat structure, the silks of G. mellonella and E. kuehniella exhibit similar tensile strength as the Bombyx and Antheraea silks. We suggest that in these latter two species, variations in the repeat length obstruct repeat alignment, but sufficiently long stretches of iterated residues get superposed to interact. In the pyralid H-fibroins, interactions of the widely separated and diverse motifs depend on the precision of repeat matching; silk is strong in G. mellonella and E. kuehniella, with 2-3 types of long homogeneous repeats, and nearly 10 times weaker in P. interpunctella, with seven types of shorter erratic repeats. The high proportion of large amino acids in the H-fibroin of pyralids has probably evolved in connection with the spinning habit of caterpillars that live in protective silk tubes and spin continuously, enlarging the tubes on one end and partly devouring the other one. The silk serves as a depot of energetically rich and essential amino acids that may be scarce in the diet.

PEGylated Silk Nanoparticles for Anticancer Drug Delivery.

Science.gov (United States)

Wongpinyochit, Thidarat; Uhlmann, Petra; Urquhart, Andrew J; Seib, F Philipp

2015-11-09

Silk has a robust clinical track record and is emerging as a promising biopolymer for drug delivery, including its use as nanomedicine. However, silk-based nanomedicines still require further refinements for full exploitation of their potential; the application of "stealth" design principals is especially necessary to support their evolution. The aim of this study was to develop and examine the potential of PEGylated silk nanoparticles as an anticancer drug delivery system. We first generated B. mori derived silk nanoparticles by driving β-sheet assembly (size 104 ± 1.7 nm, zeta potential -56 ± 5.6 mV) using nanoprecipitation. We then surface grafted polyethylene glycol (PEG) to the fabricated silk nanoparticles and verified the aqueous stability and morphology of the resulting PEGylated silk nanoparticles. We assessed the drug loading and release behavior of these nanoparticles using clinically established and emerging anticancer drugs. Overall, PEGylated silk nanoparticles showed high encapsulation efficiency (>93%) and a pH-dependent release over 14 days. Finally, we demonstrated significant cytotoxicity of drug loaded silk nanoparticles applied as single and combination nanomedicines to human breast cancer cells. In conclusion, these results, taken together with prior silk nanoparticle data, support a viable future for silk-based nanomedicines.

Sericin composition in the silk of Antheraea yamamai

Czech Academy of Sciences Publication Activity Database

Žurovec, Michal; Yonemura, N.; Kludkiewicz, Barbara; Sehnal, František; Kodrík, Dalibor; Cota Vieira, Ligia; Kučerová, Lucie; Strnad, H.; Koník, P.; Sehadová, Hana

2016-01-01

Roč. 17, č. 5 (2016), s. 1776-1787 ISSN 1525-7797 EU Projects: European Commission(XE) 316304 - MODBIOLIN Institutional support: RVO:60077344 Keywords : Galleria mellonella L. * Bombyx mori * mechanical properties Subject RIV: CE - Biochemistry OBOR OECD: Biochemistry and molecular biology Impact factor: 5.246, year: 2016 http://pubs.acs.org/doi/abs/10.1021/acs.biomac.6b00189

Self-assembly of silk-elastinlike protein polymers into three-dimensional scaffolds for biomedical applications

Science.gov (United States)

Zeng, Like

Production of brand new protein-based materials with precise control over the amino acid sequences at single residue level has been made possible by genetic engineering, through which artificial genes can be developed that encode protein-based materials with desired features. As an example, silk-elastinlike protein polymers (SELPs), composed of tandem repeats of amino acid sequence motifs from Bombyx mori (silkworm) silk and mammalian elastin, have been produced in this approach. SELPs have been studied extensively in the past two decades, however, the fundamental mechanism governing the self-assembly process to date still remains largely unresolved. Further, regardless of the unprecedented success when exploited in areas including drug delivery, gene therapy, and tissue augmentation, SELPs scaffolds as a three-dimensional cell culture model system are complicated by the inability of SELPs to provide the embedded tissue cells with appropriate biochemical stimuli essential for cell survival and function. In this dissertation, it is reported that the self-assembly of silk-elastinlike protein polymers (SELPs) into nanofibers in aqueous solutions can be modulated by tuning the curing temperature, the size of the silk blocks, and the charge of the elastin blocks. A core-sheath model was proposed for nanofiber formation, with the silk blocks in the cores and the hydrated elastin blocks in the sheaths. The folding of the silk blocks into stable cores -- affected by the size of the silk blocks and the charge of the elastin blocks -- plays a critical role in the assembly of silk-elastin nanofibers. The assembled nanofibers further form nanofiber clusters on the microscale, and the nanofiber clusters then coalesce into nanofiber micro-assemblies, interconnection of which eventually leads to the formation of three-dimensional scaffolds with distinct nanoscale and microscale features. SELP-Collagen hybrid scaffolds were also fabricated to enable independent control over the

The silkworm Bombyx mori cuticular protein CPR55 gene is regulated by the transcription factor βFTZ-F1

Directory of Open Access Journals (Sweden)

Md. Saheb Ali

2016-01-01

Full Text Available The insect cuticle is composed of various proteins and formed during the moult under a complex biological process that depends on the cross talk between hormone levels and gene expression. In the present study, we aimed to clarify the ecdysone-dependent temporal regulation mechanisms of cuticular proteins expression and the underlying control of Bombyx mori metamorphosis. The expression of CPR55 was observed from the W3 early stage and peaked at pupation when the ecdysteroid titre declined. CPR55 was induced by the ecdysone pulse, and their expression peaked at 24 h after transfer to a hormone free medium. Transcripts of CPR55 were neither observed after the 20E pulse treatment in the presence of cycloheximide nor after the addition of 20E in V4 wing discs. We analysed the upstream region of the CPR55 gene using a transient reporter assay with a gene gun system which identified only one βFTZ-F1 binding site important for cis-acting elements for the transcription activation of the luciferase reporter gene by an ecdysone pulse. Site-directed mutagenesis of this element in the context of the 589-bp promoter fragment drastically decreased the reporter activity. The nuclear protein bound to βFTZ-F1 sites was identified by an electrophoretic mobility shift assay suggesting that CPR55 expression was regulated by βFTZ-F1 through the ecdysone pulse. The results confirmed that transcription factor, BmβFTZ-F1, binds to the cis-regulatory elements in the promoter of the gene coding for cuticle protein, CPR55, and regulates its expression during B. mori metamorphosis.

The FOXO transcription factor controls insect growth and development by regulating juvenile hormone degradation in the silkworm, Bombyx mori.

Science.gov (United States)

Zeng, Baosheng; Huang, Yuping; Xu, Jun; Shiotsuki, Takahiro; Bai, Hua; Palli, Subba Reddy; Huang, Yongping; Tan, Anjiang

2017-07-14

Forkhead box O (FOXO) functions as the terminal transcription factor of the insulin signaling pathway and regulates multiple physiological processes in many organisms, including lifespan in insects. However, how FOXO interacts with hormone signaling to modulate insect growth and development is largely unknown. Here, using the transgene-based CRISPR/Cas9 system, we generated and characterized mutants of the silkworm Bombyx mori FOXO ( BmFOXO ) to elucidate its physiological functions during development of this lepidopteran insect. The BmFOXO mutant (FOXO-M) exhibited growth delays from the first larval stage and showed precocious metamorphosis, pupating at the end of the fourth instar (trimolter) rather than at the end of the fifth instar as in the wild-type (WT) animals. However, different from previous reports on precocious metamorphosis caused by juvenile hormone (JH) deficiency in silkworm mutants, the total developmental time of the larval period in the FOXO-M was comparable with that of the WT. Exogenous application of 20-hydroxyecdysone (20E) or of the JH analog rescued the trimolter phenotype. RNA-seq and gene expression analyses indicated that genes involved in JH degradation but not in JH biosynthesis were up-regulated in the FOXO-M compared with the WT animals. Moreover, we identified several FOXO-binding sites in the promoter of genes coding for JH-degradation enzymes. These results suggest that FOXO regulates JH degradation rather than its biosynthesis, which further modulates hormone homeostasis to control growth and development in B. mori In conclusion, we have uncovered a pivotal role for FOXO in regulating JH signaling to control insect development. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

Nutrigenetic screening strains of the mulberry silkworm, Bombyx mori, for nutritional efficiency.

Science.gov (United States)

Chinnaswamy, Ramesha; Lakshmi, Hothur; Kumari, Savarapu S; Anuradha, Chebba M; Kumar, Chitta S

2012-01-01

The activity of sericulture is declining due the reduction of mulberry production area in sericulture practicing countries lead to adverse effects on silkworm rearing and cocoon production. Screening for nutrigenetic traits in silkworm, Bombyx mori L. (Lepidoptera: Bombycidae) is an essential prerequisite for better understanding and development of nutritionally efficient breeds/hybrids, which show less food consumption with higher efficiency conversion. The aim of this study was to identify nutritionally efficient polyvoltine silkworm strains using the germplasm breeds RMW(2), RMW(3), RMW(4), RMG(3), RMG(1), RMG(4), RMG(5), RMG(6) and APM(1) as the control. The 1(st) day of 5(th) stage silkworm larvae of polyvoltine strains were subjected to standard gravimetric analysis until spinning for three consecutive generations covering three different seasons on 19 nutrigenetic traits. Highly significant (p ≤ 0.001) differences were found among all nutrigenetic traits of polyvoltine silkworm strains in the experimental groups. The nutritionally efficient polvoltine silkworm strains were resulted by utilizing nutrition consumption index and efficiency of conversion of ingesta/cocoon traits as the index. Higher nutritional efficiency conversions were found in the polyvoltine silkworm strains on efficiency of conversion of ingesta to cocoon and shell than control. Comparatively smaller consumption index, respiration, metabolic rate with superior relative growth rate, and quantum of food ingesta and digesta requisite per gram of cocoon and shell were shown; the lowest amount was in new polyvoltine strains compared to the control. Furthermore, based on the overall nutrigenetic traits utilized as index or 'biomarkers', three polyvoltine silkworm strains (RMG(4), RMW(2), and RMW(3)) were identified as having the potential for nutrition efficiency conversion. The data from the present study advances our knowledge for the development of nutritionally efficient silkworm breeds

Functional characterization of Bombyx mori nucleopolyhedrovirus mutant lacking late expression factor 9.

Science.gov (United States)

Zhang, Y; Shi, Y; Yu, H; Li, J; Quan, Y; Shu, T; Nie, Z; Zhang, Y; Yu, W

Baculoviridae is a family of invertebrate viruses with large double-stranded DNA genomes. Proteins encoded by some late expression factor (lef ) genes are involved in the regulation of viral gene expression. Lef-9 is one of four transcription-specific Lefs, which are components of the virus-encoded RNA polymerase, and can initiate and transcribe late and very late genes. As a multifunctional protein encoded by the Bombyx mori nucleopolyhedrovirus (BmNPV), Lef-9 may be involved in the regulation of viral propagation. However, the underlying mechanism remains unclear. To determine the role of lef-9 in baculovirus infection, lef-9-knockout virus (lef-9-KO-Bacmid virus) was constructed using the Red recombination system, and the Bac-to-Bac system was used to prepare lef-9-repaired virus (lef-9-Re-Bacmid virus). The lef-9-KO virus did not produce infectious viruses or show infection activity, while the lef-9-repaired virus recovered both. Quantitative real-time polymerase chain reaction (qRT-PCR) analysis of the transcription levels in wild-type-Bacmid, lef-9-KO-Bacmid, and lef-9-Re-Bacmid viruses showed that the lef-9-KO bacmid had little effect on viral genome replication. However, the transcription levels of the early and late viral genes, lef-3, ie-1, vp39, and p10, were significantly lower in BmN cells transfected with lef-9-KO-Bacmids than in the controls. Electron microscopy showed no visible enveloped virions in cells transfected with lef-9-KO-Bacmids, while many mature virions in cells transfected with lef-9-Re-Bacmid and wt-Bacmid were present. Thus, lef-9 was not essential for viral genome replication, but significantly affected viral gene transcription and expression in all periods of cell life cycle.

Proteomic analysis of Bombyx mori molting fluid: Insights into the molting process.

Science.gov (United States)

Liu, Hua-Wei; Wang, Luo-Ling; Tang, Xin; Dong, Zhao-Ming; Guo, Peng-Chao; Zhao, Dong-Chao; Xia, Qing-You; Zhao, Ping

2018-02-20

Molting is an essential biological process occurring multiple times throughout the life cycle of most Ecdysozoa. Molting fluids accumulate and function in the exuvial space during the molting process. In this study, we used liquid chromatography-tandem mass spectrometry to investigate the molting fluids to analyze the molecular mechanisms of molting in the silkworm, Bombyx mori. In total, 375 proteins were identified in molting fluids from the silkworm at 14-16h before pupation and eclosion, including 12 chitin metabolism-related enzymes, 35 serine proteases, 15 peptidases, and 38 protease inhibitors. Gene ontology analysis indicated that "catalytic" constitutes the most enriched function in the molting fluid. Gene expression patterns and bioinformatic analyses suggested that numerous enzymes are involved in the degradation of cuticle proteins and chitin. Protein-protein interaction network and activity analyses showed that protease inhibitors are involved in the regulation of multiple pathways in molting fluid. Additionally, many immune-related proteins may be involved in the immune defense during molting. These results provide a comprehensive proteomic insight into proteolytic enzymes and protease inhibitors in molting fluid, and will likely improve the current understanding of physiological processes in insect molting. Insect molting constitutes a dynamic physiological process. To better understand this process, we used LC-MS/MS to investigate the proteome of silkworm molting fluids and identified key proteins involved in silkworm molting. The biological processes of the old cuticle degradation pathway and immune defense response were analyzed in the proteome of silkworm molting fluid. We report that protease inhibitors serve as key factors in the regulation of the molting process. The proteomic results provide new insight into biological molting processes in insects. Copyright © 2017 Elsevier B.V. All rights reserved.

Bm59 is an early gene, but is unessential for the propagation and assembly of Bombyx mori nucleopolyhedrovirus.

Science.gov (United States)

Hu, Xiaolong; Shen, Yunwang; Zheng, Qin; Wang, Guobao; Wu, Xiaofeng; Gong, Chengliang

2016-02-01

Bombyx mori nucleopolyhedrovirus (BmNPV) is a major pathogen that specifically infects the domestic silkworm and causes serious economic loss to sericulture around the world. The function of BmNPV Bm59 gene in the viral life cycle is inconclusive. To investigate the role of Bm59 during viral infection, the transcription initiation site and temporal expression of Bm59 were analyzed, and Bm59-knockout virus was generated through homologous recombination in Escherichia coli. The results showed that Bm59 is an early transcription gene with an atypia early transcriptional start motif. Budded virion (BV) production and DNA replication in the BmN cells transfected with the Bm59-knockout virus bacmid were similar to those in the cells transfected with the wild-type virus. Electron microscopy revealed that the occlusion-derived virus can be produced in cells infected with the Bm59-knockout virus. These results indicated that Bm59 is an early gene and is not essential for viral replication or assembly of BmNPV. These findings suggested that non-essential gene (Bm59) remained in the viral genome, which may interact with other viral/host genes in a certain situation.

Identification of Bombyx mori bidensovirus VD1-ORF4 reveals a novel protein associated with viral structural component.

Science.gov (United States)

Li, Guohui; Hu, Zhaoyang; Guo, Xuli; Li, Guangtian; Tang, Qi; Wang, Peng; Chen, Keping; Yao, Qin

2013-06-01

Bombyx mori bidensovirus (BmBDV) VD1-ORF4 (open reading frame 4, ORF4) consists of 3,318 nucleotides, which codes for a predicted 1,105-amino acid protein containing a conserved DNA polymerase motif. However, its functions in viral propagation remain unknown. In the current study, the transcription of VD1-ORF4 was examined from 6 to 96 h postinfection (p.i.) by RT-PCR, 5'-RACE revealed the transcription initiation site of BmBDV ORF4 to be -16 nucleotides upstream from the start codon, and 3'-RACE revealed the transcription termination site of VD1-ORF4 to be +7 nucleotides downstream from termination codon. Three different proteins were examined in the extracts of BmBDV-infected silkworms midguts by Western blot using raised antibodies against VD1-ORF4 deduced amino acid, and a specific protein band about 53 kDa was further detected in purified virions using the same antibodies. Taken together, BmBDV VD1-ORF4 codes for three or more proteins during the viral life cycle, one of which is a 53 kDa protein and confirmed to be a component of BmBDV virion.