Alignment of silkworms and fish, observed as seismic anomalous animal behavior (SAAB) prior to the Kobe earthquake, were duplicated in a laboratory by applying a pulsed electric field assuming SAAB as electrophysiolog...Alignment of silkworms and fish, observed as seismic anomalous animal behavior (SAAB) prior to the Kobe earthquake, were duplicated in a laboratory by applying a pulsed electric field assuming SAAB as electrophysiological responses to the stimuli of seismic electric signals (SES). The animals became aligned perpendicularly to the field direction since their skeletal muscle had a higher resistivity perpendicular to the field direction than parallel to it. An electromagnetic model of a fault is proposed in which dipolar charges, ± q are generated due to the change of seismic stress, σ (t) . From a mathematical model,d q /d t=-α (d σ /d t) - q/ερ , where α is the charge generation constant like a piezoelectric coefficient, ε , the dielectric constant and ρ , the resistivity of bedrock granite. A fault having a length 2 a and a displacement or rock rupture time τ , during which the stress is changed, gives pulsed dipolar charge surface densities, +q(t, x) and -q(t, x+2a), or an apparent electric dipole moment of P(t)=2aQ(t)=2aAq(t)=αM 0[ερ/(τ-ερ)](e -t/τ -e -t/ερ ) using the earthquake moment M 0. The fault displacement, D , its initial velocity, D′ and the stress drop, Δ σ give τ=D/D′= (Δ σ/σ 0)(α/β) . The field intensity, F , and seismic current density at a fault zone, J were calculated as F=q/ε and J=F/ρ′ using ρ′ of water as to give J=0.1~1 A/m 2 sufficient to cause SAAB experimentally. The near field ultra low frequency (ULF) waves generated by P(t) give SES reciprocally proportional to the distance R .展开更多
The safety of transgenic technology is a major obstacle in the popularization and use of transgenic silkworms and their products.In sericulture,only the first filial generation(F1)hybrid eggs produced by cross-breedin...The safety of transgenic technology is a major obstacle in the popularization and use of transgenic silkworms and their products.In sericulture,only the first filial generation(F1)hybrid eggs produced by cross-breeding Japanese and Chinese original strains are usually used for the large-scale breeding of silkworms,but this may result in uncontrolled transgene dispersal during the popularization and application of the F1 hybrid transgenic eggs.To address this issue,we developed a safe and efficient strategy using the GAL4/Upstream activating sequence(UAS)system,the FLP/flippase recognition target(FRT)system,and the gonad-specific expression gene promoters(RSHP1p and Nanosp)for the germ cell-specific automatic excision of foreign DNA in the F1 hybrid transgenic silkworms.We established 2 types of activator strains,R1p::GAL4-Gr and Nsp::GAL4-Gr,containing the testis-specific GAL4 gene expression cassettes driven by RSHP1p or Nanosp,respectively,and 1 type of effector strain,UAS::FLP-Rg,containing the UAS-linked FLP gene expression cassette.The FLP recombinase-mediated sperm-specific complete excision of FRT-flanked target DNA in the F1 double-transgenic silkworms resulting from the hybridization of R1p::GAL4-Gr and UAS::FLP-Rg was 100%,whereas the complete excision efficiency resulting from the hybridization of Nsp::GAL4-Gr and UAS::FLP-Rg ranged from 13.73%to 80.3%.Additionally,we identified a gene,sw11114,that is expressed in both testis and ovary of Bombyx mori,and can be used to establish novel gonad-specific expression systems in transgenic silkworms.This strategy has the potential to fundamentally solve the safety issue in the production of F1 transgenic silkworm eggs and provides an important reference for the safety of transgenic technology in other insect species.展开更多
Comprehensive Summary Fluorescent silk has potential application in many fields such as bioimaging,tissue engineering scaffolds,luminescent marks,and dazzling fabrics.Among the methods to endow natural silk with fluor...Comprehensive Summary Fluorescent silk has potential application in many fields such as bioimaging,tissue engineering scaffolds,luminescent marks,and dazzling fabrics.Among the methods to endow natural silk with fluorescent properties,feeding silkworms with fluorescent additives is facile,low-cost and environment friendly,which has the prospect of large-scale production.In this paper,we reviewed the research progress for this aim in the past ten years,and summarized the unified characteristics for the substances that can enter the silk gland by digestive tract of silkworms.The advantages and disadvantages of various fluorescent materials for this application are compared in detail.And the future research directions are suggested to overcome the shortcomings of the present research.展开更多
The accurate identification and localization of diseased silkworms is an important task in the research of disease precision control technology and equipment development in the sericulture industry. However, the exist...The accurate identification and localization of diseased silkworms is an important task in the research of disease precision control technology and equipment development in the sericulture industry. However, the existing deep learning-based methods for this task are mainly based on image classification, which fails to provide the location information of diseased silkworms. To this end, this study proposed an object detection-based method for identifying and locating healthy and diseased silkworms. Images of mixed healthy and diseased silkworms were collected using a mobile phone, and the category and location of each silkworm were labeled using LabelImg as a labeling tool to construct an image dataset for object detection. Based on the one-step detection model YOLOv5s, the ConvNeXt-Attention-YOLOv5 (CA-YOLOv5) model was designed in which the large kernel with depth-wise separable convolution (7×7 dw-conv) of ConvNeXt was adopted to expand receptive fields and the channel attention mechanism ECANet was added to enhance the capability of feature extraction. Experiments showed that the mean average precision (mAP) values of CA-YOLOv5 for healthy and diseased silkworms reached 96.46%, which is 1.35% better than that achieved via YOLOv5s. At the same time, the overall performance of CA-YOLOv5 was significantly better than state-of-the-art one-step models, such as Single Shot MultiBox Detector (SSD), CenterNet, and EfficientDet, and even improved YOLOv5 using image attention mechanism and a lightweight backbone, like SENet-YOLOv5 and MobileNet-YOLOv5. The results of this study can provide an important basis for the accurate positioning of diseased silkworms in precision disease control technology and equipment development.展开更多
To express human insulin-like growth factor-I (hIGF-I) in transformed Bombyx mori cultured cells and silk glands, the transgenic vector pigA3GFP-hIGF-ie-neo was constructed with a neomycin resistance gene driven by th...To express human insulin-like growth factor-I (hIGF-I) in transformed Bombyx mori cultured cells and silk glands, the transgenic vector pigA3GFP-hIGF-ie-neo was constructed with a neomycin resistance gene driven by the baculovirus ie-1 promoter, and with the hIGF-I gene under the control of the silkworm sericin promoter Ser-1. The stably transformed BmN cells expressing hIGF-I were selected by using the antibiotic G418 at a final concentration of 700-800 μg/mL after the BmN cells were transfected with the piggyBac vector and the helper plasmid. The specific band of hIGF-I was detected in the transformed cells by Western blot. The expression level of hIGF-I, determined by ELISA, was about 7800 pg in 5×105 cells. Analysis of the chromosomal insertion sites by inverse PCR showed that exogenous DNA could be inserted into the cell genome randomly or at TTAA target sequence specifically for piggyBac element transposition. The transgenic vector pigA3GFP-hIGF-ie-neo was transferred into the eggs using sperm-mediated gene transfer. Finally, two transgenic silkworms were obtained after screening for the neo and gfp genes and verified by PCR and dot hybridization. The expression level of hIGF-I determined by ELISA was about 2440 pg/g of silk gland of the transgenic silkworms of the G1 generation.展开更多
Under long-term artificial selection, the domestic silkworm (Bombyx mori) has increased its silk yield tremendously in comparison with its wild progenitor, Bombyx mandarina. However, the molecular mechanism of silk ...Under long-term artificial selection, the domestic silkworm (Bombyx mori) has increased its silk yield tremendously in comparison with its wild progenitor, Bombyx mandarina. However, the molecular mechanism of silk yield increase is still unknown. Comparative analysis of long non-coding RNAs (lncRNAs) may provide some insights into understanding this phenotypic variation. In this study, using RNA sequencing technology data of silk gland in domestic and wild silkworms, we identified 599 lncRNAs in the silk gland of the silkworm. Compared with protein-coding genes, the silk gland lncRNA genes tend to have fewer exon numbers, shorter transcript length and lower GC-content. Moreover, we found that three lncRNA genes are significantly and differentially expressed between domestic and wild silkworms. The potential targets of two differentially expressed lncRNAs (DELs) (dw4sg_0040 and dw4sg_0483) and the expression-correlated genes with the two DELs are mainly enriched in the related processes of silk protein translation. This implies that these DELs may affect the phenotypic variation in silk yield between the domestic and wild silkworms through the post-transcriptional regulation of silk protein.展开更多
By using silkworms,Bombyx mori, fluorescent cocoon sex identification (FCSI) as an experimental material, direct fluorescence spectrometry of the cocoon surface indicates that the fluorescent color of silkworm cocoons...By using silkworms,Bombyx mori, fluorescent cocoon sex identification (FCSI) as an experimental material, direct fluorescence spectrometry of the cocoon surface indicates that the fluorescent color of silkworm cocoons is made up of two peaks of yellow and blue-purple fluorescence emission. The fluorescent difference between male and female cocoons is attributed to the differential absorption of yellow fluorescent substances by the midgut tissue of 5th instar female silkworms. Thin layer chromatography (TLC) and fluorescent spectra indicate that blue-purple fluorescent substances are composed of at least five blue-purple fluorescent pigments, and yellow fluorescent substances are made up of at least three. UV spectra and AlCl3 color reaction show that the three fluorescent yellow pigments are flavonoids or their glycosides. Silkworm FCSI is due to selective absorption or accumulation of the yellow fluorescent pigments by the posterior midgut cells of female 5th instar larvae. The cells of the FCSI silkworm midgut, especially the cylinder intestinal cells of the posterior midgut have a component which is a yellow fluorescent pigment-specific binding protein that may be vigorously expressed in the 5th instar larvae.展开更多
Silkworm pupa is a nourishing food with high nutritional value,but its consumption has been greatly limited given its allergenicity.Enzyme hydrolytic technique is recognized as an effective method to reduce the allerg...Silkworm pupa is a nourishing food with high nutritional value,but its consumption has been greatly limited given its allergenicity.Enzyme hydrolytic technique is recognized as an effective method to reduce the allergenicity of protein.In this study,we aimed to investigate the effect of enzymolysis on the allergenicity of silkworm pupa.Crude silkworm pupa protein was extracted through alkali extraction and acid precipitation,which included 5 proteins with the molecular weights ranging from 34 kDa to 76 kDa,and silkworm pupa were then hydrolyzed by alkaline protease.The allergenicity of silkworm pupa protein and its enzymatic hydrolysates was evaluated by establishing BALB/c mice model,and the mice were immunized via intragastric gavage and intraperitoneal injection,respectively.The results indicated that the intraperitoneal inj ection immunization route induced more by detecting with antibodies,histamine and Th2-related cytokines.Moreover,mice treated with silkworm pupa protein peptide displayed no obvious allergic symptoms,indicating that enzyme hydrolytic technique could significantly reduce the allergenicity of silkworm pupa.展开更多
[Objective] The aim of this research was to study the expression of silkworm attacin gene induced by some different microorganisms.[Method] Three kinds of microorganism,BmNPV,JM109 and Agrobacterium LBA4404,were inges...[Objective] The aim of this research was to study the expression of silkworm attacin gene induced by some different microorganisms.[Method] Three kinds of microorganism,BmNPV,JM109 and Agrobacterium LBA4404,were ingested to silkworm and the expression profile of attacin gene in hemocyte and fat body was detected by semi-quantitative PCR.And subsequently,the PCR products were cloned and sequenced for further analysis.[Result] A specific band,about 800 bp,appeared in fat body of all induced silkworms.As indicated by the results of cloning and sequencing(GenBank accession number:FJ373019),the band was produced because the 2 introns existing in normal expression form were not spliced.Furthermore,when the extended expression sequence was translated into amino acids,the translation stopped earlier by the stop codon TGA at the 5' end of the first intron of the original sequence,leading the loss of attacin C terminus.[Conclusion] There were two splicesomes of attacin gene,which had reference value to study the role of the attacin gene in silkworm immunity.展开更多
[Objective] The study aimed to breed eminent mulbery wild silb with hypersilk.[Method] Eminent mulberry wild silkworm basic materials Ye A and Ye B were bred by distant complex crossing of wild mulberry silkworm with ...[Objective] The study aimed to breed eminent mulbery wild silb with hypersilk.[Method] Eminent mulberry wild silkworm basic materials Ye A and Ye B were bred by distant complex crossing of wild mulberry silkworm with strong stress resistance and hypersilkgeneous silkworm,then hybridized with Japanese silkworm strain,the new silkworm variety "Yesanyuan" with healthiness and hypersilkgene was bred.[Ressult]The results of laboratory identification and rural productive test in Jiangsu Province showed that it has excellent feeding habit,strong stress resistance,high yield,excellent silk quality and excellent fecundity.The new silkworm variety "Yesanyuan" had been approved by Silkworm Variety Evaluation Commission of Jiangsu Province in 2008,it is suitable to rear in Yangtze River catchment for Spring and Autumn,North sericultural area for all-year.[Conclusion] The study is helpful for the development of silkworm industry.展开更多
Fluorescent silk is fundamentally important for the development of future tissue engineering scaffolds.Despite great progress in the preparation of a variety of colored silks,fluorescent silk with enhanced mechanical ...Fluorescent silk is fundamentally important for the development of future tissue engineering scaffolds.Despite great progress in the preparation of a variety of colored silks,fluorescent silk with enhanced mechanical properties has yet to be explored.In this study,we report on the fabrication of intrinsically super-strong fluorescent silk by feeding Bombyx mori silkworm carbon nanodots(CNDs).The CNDs were incorporated into silk fibroin,hindering the conformation transformation,confining crystallization,and inducing orientation of mesophase.The resultant silk exhibited super-strong mechanical properties with breaking strength of 521.9±82.7 MPa and breaking elongation of 19.2±4.3%,improvements of 55.1%and 53.6%,respectively,in comparison with regular silk.The CNDs-reinforced silk displayed intrinsic blue fluorescence when exposed to 405 nm laser and exhibited no cytotoxic effect on cells,suggesting that multi-functional silks would be potentially useful in bioimaging and other applications.展开更多
The insect brain is the central part of the neurosecretory system,which controls morphology,physiology,and behavior during the insect’s lifecycle.Lepidoptera are holometabolous insects,and their brains develop during...The insect brain is the central part of the neurosecretory system,which controls morphology,physiology,and behavior during the insect’s lifecycle.Lepidoptera are holometabolous insects,and their brains develop during the larval period and metamorphosis into the adult form.As the only fully domesticated insect,the Lepidoptera silkworm Bombyx mori experienced changes in larval brain morphology and certain behaviors during the domestication process.Hormonal regulation in insects is a key factor in multiple processes.However,how juvenile hormone(JH)signals regulate brain development in Lepidoptera species,especially in the larval stage,remains elusive.We recently identified the JH receptor Methoprene tolerant 1(Met1)as a putative domestication gene.How artificial selection on Met1 impacts brain and behavioral domestication is another important issue addressing Darwin’s theory on domestication.Here,CRISPR/Cas9-mediated knockout of Bombyx Met1 caused developmental retardation in the brain,unlike precocious pupation of the cuticle.At the whole transcriptomelevel,theecdysteroid(20-hydroxyecdysone,20 E)signaling and downstream pathways were overactivated in the mutant cuticle but not in the brain.Pathways related to cell proliferation and specialization processes,such as extracellular matrix(ECM)-receptor interaction and tyrosine metabolism pathways,were suppressed in the brain.Molecular evolutionary analysis and in vitro assay identified an amino acid replacement located in a novel motif under positive selection in B.mori,which decreased transcriptional binding activity.The B.mori MET1 protein showed a changed structure and dynamic features,as well as a weakened co-expression gene network,compared with B.mandarina.Based on comparative transcriptomic analyses,we proposed a pathway downstream of JH signaling(i.e.,tyrosine metabolism pathway)that likely contributed to silkworm larval brain development and domestication and highlighted the importance of the biogenic amine system in larval evolution during silkworm domestication.展开更多
Silkworm powder containing 1-deoxynojirimycin (DNJ) has α-glucosidase inhibitory activity and is promising as a complementary and alternative medicine (CAM) agent in Japan. Silkworm powder produced in Korea was extra...Silkworm powder containing 1-deoxynojirimycin (DNJ) has α-glucosidase inhibitory activity and is promising as a complementary and alternative medicine (CAM) agent in Japan. Silkworm powder produced in Korea was extracted with 75% ethanol. The extract was derivatized with 9-fluorenylmethyl chloroformate (FMOC-Cl), and DNJ-FMOC content was measured by HPLC. Then, alfa-glucosidase inhibition by silkworm and mulberry powder in pig liver crude enzyme was assayed using 4-nitrophenyl-alfa-D-glucopyranoside as a substrate. Silkworm powder DNJ content (0.39 to 0.58%) was higher than that in mulberry powder (0.08 to 0.12%). The alfa-glucosidase inhibitory activity of silkworm powder was more potent than that of mulberry leaves and green tea. Silkworm powder DNJ was stable upon heating to 121?C for up to 15 min.展开更多
Most animals have the ability to adapt, to some extends and in different ways, the variation or disturbance of environment. In our experiments, we forced a silkworm caterpillar to spin two, three or four thin cocoons ...Most animals have the ability to adapt, to some extends and in different ways, the variation or disturbance of environment. In our experiments, we forced a silkworm caterpillar to spin two, three or four thin cocoons by taking it out from the cocoon being constructed. The mechanical properties of these cocoons were studied by static tensile tests and dynamic mechanical thermal analysis. Though external disturbances may cause the decrease in the total weight of silk spun by the silkworm, a gradual enhancement was interestingly found in the mechanical properties of these thin cocoons. Scanning electron microscopy observations of the fractured specimens of the cocoons showed that there exist several different energy dissipation mechanisms occurred simultaneously at macro-, meso-, and micro-scales, yielding a superior capacity of cocoons to adsorb the energy of possible attacks from the outside and to protect efficiently its pupa against damage. Through evolution of millions of years, therefore, the silkworm Bombyx mori seems to have gained the ability to adapt external disturbances and to redesign a new cocoon with optimized protective function when its first cocoon has been damaged for some reasons.展开更多
To obtain water-insoluble silk fibroin (SF) materials, polyethylene glycol diglycidyl ether (PEG-DE) was selected as a crosslinking agent to prepare SF films (blends). The reaction conditions were optimized for ...To obtain water-insoluble silk fibroin (SF) materials, polyethylene glycol diglycidyl ether (PEG-DE) was selected as a crosslinking agent to prepare SF films (blends). The reaction conditions were optimized for the crosslinking of the SF molecules. The hot water stability of the blends was measured using BCA protein assay and gravimetric analysis. The molecular conformation and crystalline structure of the blends were analyzed by FTIR and XRD, respectively. When the mass ratio of SF:PEG-DE was 1.0:0.8, the hot water loss rate of the SF blends was minimized. PEG-DE could induce SF molecules to form fl-sheets during the gel reaction process, resulting in improved crystallinity and hot water dissolved resistance of the blend films. In order to demonstrate the eytotoxicity of the chemical reagents used to crosslink SF, L929 cells were seeded on the blend film (SF:PEG-DE = 1:1) and cultured for 3 days. Cells of L929 readily adhered and spread in the fusiform on the blend film resulting in high cell viability. The extracted liquid from the SF porous film did not inhibit cell proliferation, as estimated by the MTT assay.展开更多
Peptide hydrolysates of silkworm pupae protein with molecular weight of less than 5000 Da were prepared by ultrafiltration. The extracted peptide hydrolysates of silkworm pupae protein had inhibitory action on angiote...Peptide hydrolysates of silkworm pupae protein with molecular weight of less than 5000 Da were prepared by ultrafiltration. The extracted peptide hydrolysates of silkworm pupae protein had inhibitory action on angiotensin-I-converting enzyme activity in vitro. The hydrolysates were orally administered to spontaneously hypertensive rats (SHR) in one period and long-term (four weeks). The results showed that the systolic blood pressure (SBP) of the treatment groups decreased in a dose-related manner. After one oral administration of silkworm protein hydrolysates with doses of 60, 20 and 5 mg/kg, the SBP of SHR decreased by 21.5, 13.8, and 9.0 mmHg in 1.5 h. After four weeks of the treatment in 80 mg/kg, the SBP decreased by 25 mmHg, with the antihypertensive activity close to 4 mg/kg of captopril;the SBP of the 40 mg/kg dose group also decreased by 17.5 mmHg. The peptide hydrolysate did not affect the SBP in normal, non-hypertensive rats in one period and long-term treatments. The acute toxicity research showed that the peptide hydrolysates were safe and without side effects. This research would be helpful in exploring the silkworm protein peptides as functional components for the antihypertension treatment.展开更多
Objective:To establish an efficacious and efficient fermentation method of enhancing the anti-adipogenesis effect of mulberry(Morus alba) leaves using Cordyceps militais.Methods:Dried mulberry leaves,dried mulberry le...Objective:To establish an efficacious and efficient fermentation method of enhancing the anti-adipogenesis effect of mulberry(Morus alba) leaves using Cordyceps militais.Methods:Dried mulberry leaves,dried mulberry leaves with50% raw silkworm pupa and raw silkworm pupa were fermented with Cordyceps militais for 4 weeks at 25℃,after which the dried mulberry leaves and fermented product were extracted with 70%ethanol and subjected to high performance liquid chromatography(HPLC).The contents of cordycepin,pelargonidin,chlorogenic acid,iso-quercetin and caffeic acid were determined.We then used the 3 T3-L1 cells to investigate whether extracts of fermentation enhanced anti-adipogenesis activity in vitro.Results:HPLC showed that fermentation changed the contents of cordycepin,pelargonidin,chlorogenic acid,iso-quercetin and caffeic acid.Furthermore,fermented dried mulberry leaves with 50% raw silkworm pupa had a better efficacy of anti-adipogenesis than dried mulberry leaves,fermented dried mulberry leaves and fermented silkworm pupa and inhibited triglycerides accumulation and glucose consumption.Additionally,fermented dried mulberry leaves with50% raw silkworm pupa inhibited PPAR-γ signaling.Conclusions:Fermentation with Cordyceps militaris enhanced antiadipogenesis efficacy of mulberry leaves.展开更多
1.Estimates of genetic variance and covariance for individual characters showed that cocoon weight was controlled by both gene direct effect and maternal effect;Cocoon shell weight was controlled by gene direct effect...1.Estimates of genetic variance and covariance for individual characters showed that cocoon weight was controlled by both gene direct effect and maternal effect;Cocoon shell weight was controlled by gene direct effect mainly;Cocoon shell ratio was mainly due to maternal effect and se x-linked effect.2.Estimates of genetic covariance components of each pair of ch aracters indicated that there were high significant positive relationships among most of genetic effects except maternal additive effect in cocoon weight and cocoon shell weight.There was a high positive relationship idirect effect between cocoon weight and cocoon shell ratio,but in cytop lasm effect and maternal effect were high negative relationships between them.Also there were high positive relationships in direct effect and maternal dominance between cocoon shell weight and cocoon shell ratio.3.Predictions of gene effects pointed out that sex-chromosome effects (Σi8=1Lii) on cocoon weight and cocoon shell weight both were lar ger positive values,that means cocoon weight and cocoon shell weight of females are generally higher than those of males in Silkworm. Standardized donmiance directions of direct effects on cocoon weight and cocoon shell weight were high positive values,but standardized domiance directieon of maternal effects on both of them were high negative values,it showed the two characters had larger heterosis in F1 generation and depressed in F2 generation.Sex-chromosome effect (Σi8=1Lii) on cocoon she11 ratio was high negative value,explaining that females usually have lower cocoon shell ratio than males.Standardized domiance directions of direct effect and maternal effect on cocoon shell ratio were not significant,predicting that the heterosis of cocoon shell ratio in F1 generation is not obvious comparing to cocoon weight and cocoon shell weight.展开更多
文摘Alignment of silkworms and fish, observed as seismic anomalous animal behavior (SAAB) prior to the Kobe earthquake, were duplicated in a laboratory by applying a pulsed electric field assuming SAAB as electrophysiological responses to the stimuli of seismic electric signals (SES). The animals became aligned perpendicularly to the field direction since their skeletal muscle had a higher resistivity perpendicular to the field direction than parallel to it. An electromagnetic model of a fault is proposed in which dipolar charges, ± q are generated due to the change of seismic stress, σ (t) . From a mathematical model,d q /d t=-α (d σ /d t) - q/ερ , where α is the charge generation constant like a piezoelectric coefficient, ε , the dielectric constant and ρ , the resistivity of bedrock granite. A fault having a length 2 a and a displacement or rock rupture time τ , during which the stress is changed, gives pulsed dipolar charge surface densities, +q(t, x) and -q(t, x+2a), or an apparent electric dipole moment of P(t)=2aQ(t)=2aAq(t)=αM 0[ερ/(τ-ερ)](e -t/τ -e -t/ερ ) using the earthquake moment M 0. The fault displacement, D , its initial velocity, D′ and the stress drop, Δ σ give τ=D/D′= (Δ σ/σ 0)(α/β) . The field intensity, F , and seismic current density at a fault zone, J were calculated as F=q/ε and J=F/ρ′ using ρ′ of water as to give J=0.1~1 A/m 2 sufficient to cause SAAB experimentally. The near field ultra low frequency (ULF) waves generated by P(t) give SES reciprocally proportional to the distance R .
基金This work was supported by the National Natural Science Foundation of China(31801126)the Chongqing Talents:Exceptional Young Talents Project(cstc2022ycjhbgzxm0019)the Doctoral Start-up Foundation of Southwest University(SWU120010).
文摘The safety of transgenic technology is a major obstacle in the popularization and use of transgenic silkworms and their products.In sericulture,only the first filial generation(F1)hybrid eggs produced by cross-breeding Japanese and Chinese original strains are usually used for the large-scale breeding of silkworms,but this may result in uncontrolled transgene dispersal during the popularization and application of the F1 hybrid transgenic eggs.To address this issue,we developed a safe and efficient strategy using the GAL4/Upstream activating sequence(UAS)system,the FLP/flippase recognition target(FRT)system,and the gonad-specific expression gene promoters(RSHP1p and Nanosp)for the germ cell-specific automatic excision of foreign DNA in the F1 hybrid transgenic silkworms.We established 2 types of activator strains,R1p::GAL4-Gr and Nsp::GAL4-Gr,containing the testis-specific GAL4 gene expression cassettes driven by RSHP1p or Nanosp,respectively,and 1 type of effector strain,UAS::FLP-Rg,containing the UAS-linked FLP gene expression cassette.The FLP recombinase-mediated sperm-specific complete excision of FRT-flanked target DNA in the F1 double-transgenic silkworms resulting from the hybridization of R1p::GAL4-Gr and UAS::FLP-Rg was 100%,whereas the complete excision efficiency resulting from the hybridization of Nsp::GAL4-Gr and UAS::FLP-Rg ranged from 13.73%to 80.3%.Additionally,we identified a gene,sw11114,that is expressed in both testis and ovary of Bombyx mori,and can be used to establish novel gonad-specific expression systems in transgenic silkworms.This strategy has the potential to fundamentally solve the safety issue in the production of F1 transgenic silkworm eggs and provides an important reference for the safety of transgenic technology in other insect species.
基金by the National Natural Science Foundation of China(21975048,21771039)the Shanghai Science and Technology Committee(19Dz2270100).
文摘Comprehensive Summary Fluorescent silk has potential application in many fields such as bioimaging,tissue engineering scaffolds,luminescent marks,and dazzling fabrics.Among the methods to endow natural silk with fluorescent properties,feeding silkworms with fluorescent additives is facile,low-cost and environment friendly,which has the prospect of large-scale production.In this paper,we reviewed the research progress for this aim in the past ten years,and summarized the unified characteristics for the substances that can enter the silk gland by digestive tract of silkworms.The advantages and disadvantages of various fluorescent materials for this application are compared in detail.And the future research directions are suggested to overcome the shortcomings of the present research.
基金support provided by the Sichuan Science and Technology Program,China (Grant No.2023NSFSC0498)the National Modern Agricultural Industrial Technology System Special Project,China (Grant No.CARS-18).
文摘The accurate identification and localization of diseased silkworms is an important task in the research of disease precision control technology and equipment development in the sericulture industry. However, the existing deep learning-based methods for this task are mainly based on image classification, which fails to provide the location information of diseased silkworms. To this end, this study proposed an object detection-based method for identifying and locating healthy and diseased silkworms. Images of mixed healthy and diseased silkworms were collected using a mobile phone, and the category and location of each silkworm were labeled using LabelImg as a labeling tool to construct an image dataset for object detection. Based on the one-step detection model YOLOv5s, the ConvNeXt-Attention-YOLOv5 (CA-YOLOv5) model was designed in which the large kernel with depth-wise separable convolution (7×7 dw-conv) of ConvNeXt was adopted to expand receptive fields and the channel attention mechanism ECANet was added to enhance the capability of feature extraction. Experiments showed that the mean average precision (mAP) values of CA-YOLOv5 for healthy and diseased silkworms reached 96.46%, which is 1.35% better than that achieved via YOLOv5s. At the same time, the overall performance of CA-YOLOv5 was significantly better than state-of-the-art one-step models, such as Single Shot MultiBox Detector (SSD), CenterNet, and EfficientDet, and even improved YOLOv5 using image attention mechanism and a lightweight backbone, like SENet-YOLOv5 and MobileNet-YOLOv5. The results of this study can provide an important basis for the accurate positioning of diseased silkworms in precision disease control technology and equipment development.
基金Supported by the National Basic Research Program of China (Grant No. 2005CB121000)the National Natural Science Foundation of China (Grant No. 30671590)
文摘To express human insulin-like growth factor-I (hIGF-I) in transformed Bombyx mori cultured cells and silk glands, the transgenic vector pigA3GFP-hIGF-ie-neo was constructed with a neomycin resistance gene driven by the baculovirus ie-1 promoter, and with the hIGF-I gene under the control of the silkworm sericin promoter Ser-1. The stably transformed BmN cells expressing hIGF-I were selected by using the antibiotic G418 at a final concentration of 700-800 μg/mL after the BmN cells were transfected with the piggyBac vector and the helper plasmid. The specific band of hIGF-I was detected in the transformed cells by Western blot. The expression level of hIGF-I, determined by ELISA, was about 7800 pg in 5×105 cells. Analysis of the chromosomal insertion sites by inverse PCR showed that exogenous DNA could be inserted into the cell genome randomly or at TTAA target sequence specifically for piggyBac element transposition. The transgenic vector pigA3GFP-hIGF-ie-neo was transferred into the eggs using sperm-mediated gene transfer. Finally, two transgenic silkworms were obtained after screening for the neo and gfp genes and verified by PCR and dot hybridization. The expression level of hIGF-I determined by ELISA was about 2440 pg/g of silk gland of the transgenic silkworms of the G1 generation.
文摘Under long-term artificial selection, the domestic silkworm (Bombyx mori) has increased its silk yield tremendously in comparison with its wild progenitor, Bombyx mandarina. However, the molecular mechanism of silk yield increase is still unknown. Comparative analysis of long non-coding RNAs (lncRNAs) may provide some insights into understanding this phenotypic variation. In this study, using RNA sequencing technology data of silk gland in domestic and wild silkworms, we identified 599 lncRNAs in the silk gland of the silkworm. Compared with protein-coding genes, the silk gland lncRNA genes tend to have fewer exon numbers, shorter transcript length and lower GC-content. Moreover, we found that three lncRNA genes are significantly and differentially expressed between domestic and wild silkworms. The potential targets of two differentially expressed lncRNAs (DELs) (dw4sg_0040 and dw4sg_0483) and the expression-correlated genes with the two DELs are mainly enriched in the related processes of silk protein translation. This implies that these DELs may affect the phenotypic variation in silk yield between the domestic and wild silkworms through the post-transcriptional regulation of silk protein.
基金supported by the National High Technology Research and Development Program (Grant No. 2006AA10A118)the Earmarked Fund for Modern Agro-industry Technology Research System,China
文摘By using silkworms,Bombyx mori, fluorescent cocoon sex identification (FCSI) as an experimental material, direct fluorescence spectrometry of the cocoon surface indicates that the fluorescent color of silkworm cocoons is made up of two peaks of yellow and blue-purple fluorescence emission. The fluorescent difference between male and female cocoons is attributed to the differential absorption of yellow fluorescent substances by the midgut tissue of 5th instar female silkworms. Thin layer chromatography (TLC) and fluorescent spectra indicate that blue-purple fluorescent substances are composed of at least five blue-purple fluorescent pigments, and yellow fluorescent substances are made up of at least three. UV spectra and AlCl3 color reaction show that the three fluorescent yellow pigments are flavonoids or their glycosides. Silkworm FCSI is due to selective absorption or accumulation of the yellow fluorescent pigments by the posterior midgut cells of female 5th instar larvae. The cells of the FCSI silkworm midgut, especially the cylinder intestinal cells of the posterior midgut have a component which is a yellow fluorescent pigment-specific binding protein that may be vigorously expressed in the 5th instar larvae.
基金supported by Special Project on the Integration of Industry,Education and Research of Guangdong Provine(2013B090600060)National Key R&D Program of China(2018YFC1604205)National Natural Science Foundation of China(31760431)。
文摘Silkworm pupa is a nourishing food with high nutritional value,but its consumption has been greatly limited given its allergenicity.Enzyme hydrolytic technique is recognized as an effective method to reduce the allergenicity of protein.In this study,we aimed to investigate the effect of enzymolysis on the allergenicity of silkworm pupa.Crude silkworm pupa protein was extracted through alkali extraction and acid precipitation,which included 5 proteins with the molecular weights ranging from 34 kDa to 76 kDa,and silkworm pupa were then hydrolyzed by alkaline protease.The allergenicity of silkworm pupa protein and its enzymatic hydrolysates was evaluated by establishing BALB/c mice model,and the mice were immunized via intragastric gavage and intraperitoneal injection,respectively.The results indicated that the intraperitoneal inj ection immunization route induced more by detecting with antibodies,histamine and Th2-related cytokines.Moreover,mice treated with silkworm pupa protein peptide displayed no obvious allergic symptoms,indicating that enzyme hydrolytic technique could significantly reduce the allergenicity of silkworm pupa.
基金Supported by Educational Commission of Shaanxi Province(08JK211)Special Scientific Research Foundation Project of Ankang University(AYQDZR200711)~~
文摘[Objective] The aim of this research was to study the expression of silkworm attacin gene induced by some different microorganisms.[Method] Three kinds of microorganism,BmNPV,JM109 and Agrobacterium LBA4404,were ingested to silkworm and the expression profile of attacin gene in hemocyte and fat body was detected by semi-quantitative PCR.And subsequently,the PCR products were cloned and sequenced for further analysis.[Result] A specific band,about 800 bp,appeared in fat body of all induced silkworms.As indicated by the results of cloning and sequencing(GenBank accession number:FJ373019),the band was produced because the 2 introns existing in normal expression form were not spliced.Furthermore,when the extended expression sequence was translated into amino acids,the translation stopped earlier by the stop codon TGA at the 5' end of the first intron of the original sequence,leading the loss of attacin C terminus.[Conclusion] There were two splicesomes of attacin gene,which had reference value to study the role of the attacin gene in silkworm immunity.
基金Supported by National Key Technology R&D Program(2006BAD06B03)~~
文摘[Objective] The study aimed to breed eminent mulbery wild silb with hypersilk.[Method] Eminent mulberry wild silkworm basic materials Ye A and Ye B were bred by distant complex crossing of wild mulberry silkworm with strong stress resistance and hypersilkgeneous silkworm,then hybridized with Japanese silkworm strain,the new silkworm variety "Yesanyuan" with healthiness and hypersilkgene was bred.[Ressult]The results of laboratory identification and rural productive test in Jiangsu Province showed that it has excellent feeding habit,strong stress resistance,high yield,excellent silk quality and excellent fecundity.The new silkworm variety "Yesanyuan" had been approved by Silkworm Variety Evaluation Commission of Jiangsu Province in 2008,it is suitable to rear in Yangtze River catchment for Spring and Autumn,North sericultural area for all-year.[Conclusion] The study is helpful for the development of silkworm industry.
基金sponsored by the National Key Research and Development Program of China(2016YFA0201700,2016YFA0201702)the Fundamental Research Funds for the Central Universities(2232019A3-06,2232019D3-02)+2 种基金the National Key Research and Development Program of China(2018YFC1105800)the National Natural Science Foundation of China(21674018,51903045)the Shanghai Belt and Road Joint Laboratory of Advanced Fiber and Low-Dimension Materials(18520750400).
文摘Fluorescent silk is fundamentally important for the development of future tissue engineering scaffolds.Despite great progress in the preparation of a variety of colored silks,fluorescent silk with enhanced mechanical properties has yet to be explored.In this study,we report on the fabrication of intrinsically super-strong fluorescent silk by feeding Bombyx mori silkworm carbon nanodots(CNDs).The CNDs were incorporated into silk fibroin,hindering the conformation transformation,confining crystallization,and inducing orientation of mesophase.The resultant silk exhibited super-strong mechanical properties with breaking strength of 521.9±82.7 MPa and breaking elongation of 19.2±4.3%,improvements of 55.1%and 53.6%,respectively,in comparison with regular silk.The CNDs-reinforced silk displayed intrinsic blue fluorescence when exposed to 405 nm laser and exhibited no cytotoxic effect on cells,suggesting that multi-functional silks would be potentially useful in bioimaging and other applications.
基金supported by the National Natural Science Foundation of China(32070411,31720103916,31330071,31672494)Natural Science Foundation of Guangdong Province(2019A1515011012)Strategic Priority Research Program of the Chinese Academy of Sciences(XDB11010600)。
文摘The insect brain is the central part of the neurosecretory system,which controls morphology,physiology,and behavior during the insect’s lifecycle.Lepidoptera are holometabolous insects,and their brains develop during the larval period and metamorphosis into the adult form.As the only fully domesticated insect,the Lepidoptera silkworm Bombyx mori experienced changes in larval brain morphology and certain behaviors during the domestication process.Hormonal regulation in insects is a key factor in multiple processes.However,how juvenile hormone(JH)signals regulate brain development in Lepidoptera species,especially in the larval stage,remains elusive.We recently identified the JH receptor Methoprene tolerant 1(Met1)as a putative domestication gene.How artificial selection on Met1 impacts brain and behavioral domestication is another important issue addressing Darwin’s theory on domestication.Here,CRISPR/Cas9-mediated knockout of Bombyx Met1 caused developmental retardation in the brain,unlike precocious pupation of the cuticle.At the whole transcriptomelevel,theecdysteroid(20-hydroxyecdysone,20 E)signaling and downstream pathways were overactivated in the mutant cuticle but not in the brain.Pathways related to cell proliferation and specialization processes,such as extracellular matrix(ECM)-receptor interaction and tyrosine metabolism pathways,were suppressed in the brain.Molecular evolutionary analysis and in vitro assay identified an amino acid replacement located in a novel motif under positive selection in B.mori,which decreased transcriptional binding activity.The B.mori MET1 protein showed a changed structure and dynamic features,as well as a weakened co-expression gene network,compared with B.mandarina.Based on comparative transcriptomic analyses,we proposed a pathway downstream of JH signaling(i.e.,tyrosine metabolism pathway)that likely contributed to silkworm larval brain development and domestication and highlighted the importance of the biogenic amine system in larval evolution during silkworm domestication.
文摘Silkworm powder containing 1-deoxynojirimycin (DNJ) has α-glucosidase inhibitory activity and is promising as a complementary and alternative medicine (CAM) agent in Japan. Silkworm powder produced in Korea was extracted with 75% ethanol. The extract was derivatized with 9-fluorenylmethyl chloroformate (FMOC-Cl), and DNJ-FMOC content was measured by HPLC. Then, alfa-glucosidase inhibition by silkworm and mulberry powder in pig liver crude enzyme was assayed using 4-nitrophenyl-alfa-D-glucopyranoside as a substrate. Silkworm powder DNJ content (0.39 to 0.58%) was higher than that in mulberry powder (0.08 to 0.12%). The alfa-glucosidase inhibitory activity of silkworm powder was more potent than that of mulberry leaves and green tea. Silkworm powder DNJ was stable upon heating to 121?C for up to 15 min.
基金the National Natural Science Foundation of China (10402017,10732050,10525210,10121202)
文摘Most animals have the ability to adapt, to some extends and in different ways, the variation or disturbance of environment. In our experiments, we forced a silkworm caterpillar to spin two, three or four thin cocoons by taking it out from the cocoon being constructed. The mechanical properties of these cocoons were studied by static tensile tests and dynamic mechanical thermal analysis. Though external disturbances may cause the decrease in the total weight of silk spun by the silkworm, a gradual enhancement was interestingly found in the mechanical properties of these thin cocoons. Scanning electron microscopy observations of the fractured specimens of the cocoons showed that there exist several different energy dissipation mechanisms occurred simultaneously at macro-, meso-, and micro-scales, yielding a superior capacity of cocoons to adsorb the energy of possible attacks from the outside and to protect efficiently its pupa against damage. Through evolution of millions of years, therefore, the silkworm Bombyx mori seems to have gained the ability to adapt external disturbances and to redesign a new cocoon with optimized protective function when its first cocoon has been damaged for some reasons.
基金Funded by National Natural Science Foundation of China(Nos.51173125 and 51473108)Natural Science Foundation of Jiangsu Province of China(Nos.BK2012633 and BK2041210)+2 种基金College Natural Science Research Project of Jiangsu Province of China(No.12KJA43004)the Science and Technology Development Foundation of Suzhou of China(Nos.SYG201001 and SS201341)Priority Academic Program Development of Jiangsu Higher Education Institutions[PAPD]
文摘To obtain water-insoluble silk fibroin (SF) materials, polyethylene glycol diglycidyl ether (PEG-DE) was selected as a crosslinking agent to prepare SF films (blends). The reaction conditions were optimized for the crosslinking of the SF molecules. The hot water stability of the blends was measured using BCA protein assay and gravimetric analysis. The molecular conformation and crystalline structure of the blends were analyzed by FTIR and XRD, respectively. When the mass ratio of SF:PEG-DE was 1.0:0.8, the hot water loss rate of the SF blends was minimized. PEG-DE could induce SF molecules to form fl-sheets during the gel reaction process, resulting in improved crystallinity and hot water dissolved resistance of the blend films. In order to demonstrate the eytotoxicity of the chemical reagents used to crosslink SF, L929 cells were seeded on the blend film (SF:PEG-DE = 1:1) and cultured for 3 days. Cells of L929 readily adhered and spread in the fusiform on the blend film resulting in high cell viability. The extracted liquid from the SF porous film did not inhibit cell proliferation, as estimated by the MTT assay.
文摘Peptide hydrolysates of silkworm pupae protein with molecular weight of less than 5000 Da were prepared by ultrafiltration. The extracted peptide hydrolysates of silkworm pupae protein had inhibitory action on angiotensin-I-converting enzyme activity in vitro. The hydrolysates were orally administered to spontaneously hypertensive rats (SHR) in one period and long-term (four weeks). The results showed that the systolic blood pressure (SBP) of the treatment groups decreased in a dose-related manner. After one oral administration of silkworm protein hydrolysates with doses of 60, 20 and 5 mg/kg, the SBP of SHR decreased by 21.5, 13.8, and 9.0 mmHg in 1.5 h. After four weeks of the treatment in 80 mg/kg, the SBP decreased by 25 mmHg, with the antihypertensive activity close to 4 mg/kg of captopril;the SBP of the 40 mg/kg dose group also decreased by 17.5 mmHg. The peptide hydrolysate did not affect the SBP in normal, non-hypertensive rats in one period and long-term treatments. The acute toxicity research showed that the peptide hydrolysates were safe and without side effects. This research would be helpful in exploring the silkworm protein peptides as functional components for the antihypertension treatment.
基金This work was supported by Korea Institute of Planning and Evaluation for Technology in Food,Agriculture,Forestry and Fisheries(IPET)through High Value-added Food Technology Development Program,funded by Ministry of Agriculture,Food and Rural Affairs(MAFRA)(116027032HD020).
文摘Objective:To establish an efficacious and efficient fermentation method of enhancing the anti-adipogenesis effect of mulberry(Morus alba) leaves using Cordyceps militais.Methods:Dried mulberry leaves,dried mulberry leaves with50% raw silkworm pupa and raw silkworm pupa were fermented with Cordyceps militais for 4 weeks at 25℃,after which the dried mulberry leaves and fermented product were extracted with 70%ethanol and subjected to high performance liquid chromatography(HPLC).The contents of cordycepin,pelargonidin,chlorogenic acid,iso-quercetin and caffeic acid were determined.We then used the 3 T3-L1 cells to investigate whether extracts of fermentation enhanced anti-adipogenesis activity in vitro.Results:HPLC showed that fermentation changed the contents of cordycepin,pelargonidin,chlorogenic acid,iso-quercetin and caffeic acid.Furthermore,fermented dried mulberry leaves with 50% raw silkworm pupa had a better efficacy of anti-adipogenesis than dried mulberry leaves,fermented dried mulberry leaves and fermented silkworm pupa and inhibited triglycerides accumulation and glucose consumption.Additionally,fermented dried mulberry leaves with50% raw silkworm pupa inhibited PPAR-γ signaling.Conclusions:Fermentation with Cordyceps militaris enhanced antiadipogenesis efficacy of mulberry leaves.
文摘1.Estimates of genetic variance and covariance for individual characters showed that cocoon weight was controlled by both gene direct effect and maternal effect;Cocoon shell weight was controlled by gene direct effect mainly;Cocoon shell ratio was mainly due to maternal effect and se x-linked effect.2.Estimates of genetic covariance components of each pair of ch aracters indicated that there were high significant positive relationships among most of genetic effects except maternal additive effect in cocoon weight and cocoon shell weight.There was a high positive relationship idirect effect between cocoon weight and cocoon shell ratio,but in cytop lasm effect and maternal effect were high negative relationships between them.Also there were high positive relationships in direct effect and maternal dominance between cocoon shell weight and cocoon shell ratio.3.Predictions of gene effects pointed out that sex-chromosome effects (Σi8=1Lii) on cocoon weight and cocoon shell weight both were lar ger positive values,that means cocoon weight and cocoon shell weight of females are generally higher than those of males in Silkworm. Standardized donmiance directions of direct effects on cocoon weight and cocoon shell weight were high positive values,but standardized domiance directieon of maternal effects on both of them were high negative values,it showed the two characters had larger heterosis in F1 generation and depressed in F2 generation.Sex-chromosome effect (Σi8=1Lii) on cocoon she11 ratio was high negative value,explaining that females usually have lower cocoon shell ratio than males.Standardized domiance directions of direct effect and maternal effect on cocoon shell ratio were not significant,predicting that the heterosis of cocoon shell ratio in F1 generation is not obvious comparing to cocoon weight and cocoon shell weight.