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
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
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 b...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 700-800μg/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
Silkworm silks have been widely used in a variety of fields due to their sensuousness, luster and excellent mechanical properties. Researchers have paid special attention in improving the mechanical properties of silk...Silkworm silks have been widely used in a variety of fields due to their sensuousness, luster and excellent mechanical properties. Researchers have paid special attention in improving the mechanical properties of silks. In this work,Bombyx mori larval silkworms are injected with graphene quantum dots(GQDs) through a vascular injection to enhance mechanical properties of the silkworm silks. The GQDs can be incorporated into the silkworm silk gland easily due to hemolymph circulation and influence the spinning process of silkworm. The breaking strength, elongation at break and toughness modulus of the silks increase by 2.74, 1.33 and 3.62 times, respectively, by injecting per individual with 0.6 μg GQDs. Wide-angle X-ray scattering indicates that the size ofβ-sheet nanocrystals in GQDs-silks is smaller than that in control-silks. Infrared spectra suggest that GQDs confine the conformation transition of silk fibroin to β-sheet from random coil/α-helix, and the change of the size and content of β-sheet may be the reason for the improvement of the mechanical properties. The toxicity and safety limit of GQDs incorporated into each silkworm is also evaluated, and the results show that the upmost dose of GQDs per silkworm is30.0 μg. The successful obtainment of reinforced silks by in vivo uptake of GQDs provides a promising route to produce high-strength silks.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 is ...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
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
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
The domesticated silkworm(Bombyx mori)has evolved a highly efficient nitrogen utilization system to support silk production.The silk glands play a pleiotropic role in sequestering nitrogen resources for silk synthesis...The domesticated silkworm(Bombyx mori)has evolved a highly efficient nitrogen utilization system to support silk production.The silk glands play a pleiotropic role in sequestering nitrogen resources for silk synthesis,mitigating aminoacidemia by assimilating free amino acids,and reallocating nitrogen during metamorphosis through programmed cell death.However,the specific functions of nitrogen metabolism-related genes in this process remain unclear.Using CRISPR/Cas9-based gene editing,mutations were generated in glutamine synthetase(GS),glutamate synthetase(GOGAT),asparagine synthetase(AS),glutamate dehydrogenase(GDH)and glutamate oxaloacetate transaminase 1(GOT1).Disruption of GS,GOGAT,and AS consistently reduced silkworm cocoon and pupal weight and significantly down-regulated silk protein gene transcription,whereas GOT1 mutation had no such effect.GOGAT mutants exhibited abnormally enlarged silk glands,whereas GS and AS mutants showed delayed programmed cell death in the silk glands.In contrast,GOT1 mutants displayed normal silk gland morphology but were consistently smaller.Disruption of GS,GOGAT,and AS led to more extensive transcriptional changes,including altered expression of transcription factors in the silk glands,compared with GOT1 mutants.Both GS and GOGAT mutants exhibited up-regulation of AS and GDH,while only GOGAT mutants displayed elevated AS enzymatic activity,suggesting that GOGAT may compete with AS for glutamine in the silk glands to support silk protein synthesis.AS mutants showed significantly elevated GOT activity and up-regulation of several metabolic pathways,indicating that AS may functionally interact with GOT in regulating both silk gland development and programmed cell death during metamorphosis.展开更多
The anti-inflammatory properties of silkworm pupa peptide(SPP)have been recognized for their potential benefits in colitis treatment.However,the underlying mechanism of SPP in colitis animal models remains unclear.The...The anti-inflammatory properties of silkworm pupa peptide(SPP)have been recognized for their potential benefits in colitis treatment.However,the underlying mechanism of SPP in colitis animal models remains unclear.The objective of our work was to investigate the improving effect and the mechanism of action of SPP on a mouse model of dextran sulfate sodium(DSS)-induced colitis.The findings suggested that SPP effectively eased ulcerative colitis(UC)symptoms in mice by decreasing disease activity index,ameliorating histopathological injury,and decreasing serum and colonic markers of inflammation.In addition,our research findings demonstrated that SPP restored intestinal barrier function by increasing the production of tight junction proteins such as zonula occludens-1(ZO-1),claudin-1,claudin-3,occludin,and adherens junction protein E-cadherin1.Further,SPP supplementation enhanced the concentration of short-chain fatty acids and positively altered the makeup of the gut bacteria in the mice's gut.These findings underscore SPP's ability to slow the progression of colitis and point to its possible use as a functional component in dietary supplements for the prevention of early-stage colitis.展开更多
[ Objective] The aim of this study was to investigate effects of various inducers on the expression of cytochrome P450 CYP305 B1 V1 Gene in different tissues of wild mulberry silkworm. [ Method] Referring to the mRNA ...[ Objective] The aim of this study was to investigate effects of various inducers on the expression of cytochrome P450 CYP305 B1 V1 Gene in different tissues of wild mulberry silkworm. [ Method] Referring to the mRNA sequence of CYP305 B1 V1 Gene published in GenBank for wild mulberry silkworm, one pair of primers was designed, and the expression of cytochrome P450 CYP305 B1 V1 Gene in different tissues of wild mulberry silkworm treated by NaF, rutin, cypermethrin and ecdysone was also analyzed by the semi - quantitative RT - PCR. Furthermore, homology comparison and phylogenetic analysis for amino acid sequences of this gene were studied. [ Result] Rutin, cypermethrin and NaF had effects on the expression of P450 CYP305 B1 V1 Gene in different tissues of wild mulberry silkworm, while ecdysone had no significant effect. Homology comparison for amino acids indicated that the amino acid sequence of this gene was the most similar to that of CYP305 B1 gene in Bombyx mori with 100% amino acid identity, and highly similar to those of Tribolium casmneum CYP305A1, Apis mellifera CYP305A1, Drosophi- la melanogaster CYP305A1, Anopheles gambiae CYP305A2and Culex pipiens quinquefasciatus CYP2LI. [ Conclusion] CYP305 B1 V1 Gene of wild mulberry silkworm is likely to mainly take part in the metabolism of exogenous compounds, which is of great significance for revealing the function of cytochrome P450 and the metabolic mechanism of different drugs.展开更多
[Objective] The research aimed to obtain an effectively-decomposing strain of silkworm chrysalis protein and discuss its enzymatic properties.[Method] The effectively-decomposing bacteria of protein was isolated from ...[Objective] The research aimed to obtain an effectively-decomposing strain of silkworm chrysalis protein and discuss its enzymatic properties.[Method] The effectively-decomposing bacteria of protein was isolated from the decayed silkworm chrysalis by using dilution plate and its enzymatic properties were tested after primary screening and second screening.The enzyme activity was determined and the intermediate and small molecule protein content in silkworm chrysalis was measured after solid-state fermentati...展开更多
[Objective] The study aimed to provide theoretical basis for development and application of molecular marker breeding technique to obtain Bombyx mori near-isogenic lines （NILs）. [Method] Thermotolerance gene was int...[Objective] The study aimed to provide theoretical basis for development and application of molecular marker breeding technique to obtain Bombyx mori near-isogenic lines （NILs）. [Method] Thermotolerance gene was introduced into sensitive variety Ou17 by developing NILs and recurrent backcross,then through six generations of backcross,thermotolerance-assisted selection,and two generations of self-cross. [Result] Bombyx mori NILs carrying thermotolerance gene （new germplasm） were produced. Meanwhile,thermotolerance level of progenies of each backcross and molecular markers of NILs were determined,and then attempts were made to produce practical thermotolerance hybrids by using thermotolerance varieties whose thermotolerance gene is linked to SSR markers. [Conclusion] The study successfully construct thermotolerance NILs,monitor thermotolerance level and breeding results of progenies of each backcross,and determine molecular marker of NILs.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
A simple and green technique has been developed to prepare hierarchical biomorphic ZrO2- CeO2, using silkworm silk as the template. Different from traditional immersion technics, the whole synthesis process depends mo...A simple and green technique has been developed to prepare hierarchical biomorphic ZrO2- CeO2, using silkworm silk as the template. Different from traditional immersion technics, the whole synthesis process depends more on the restriction or direction functions of the silkworm silk template. The analytic results showed that ZrO2-CeO2 exhibited a well-crystallized hierarchically interwoven hollow fiber structure with 16-28 μm in diameter. The grain size of the sample calcined at 800 ℃ was about 14 nm. Consequently, the interwoven meshwork at three dimensions is formed due to the direction of biotemplate. The action mechanism is summarily discussed here. It may bring the biomorphic ZrO2-CeO2 nanomaterials with hierarchical interwoven structures to more applications, such as catalysts.展开更多
[Objective] The aim of this study was to optimize the conditions of chitinase-produce strains.[Method] A kind of screened chitinase-produce strain G-254 was habituated cultured,and then the single factor experiment wa...[Objective] The aim of this study was to optimize the conditions of chitinase-produce strains.[Method] A kind of screened chitinase-produce strain G-254 was habituated cultured,and then the single factor experiment was carried out to explore the effects of different carbon source,nitrogen source and inorganic salt on the activity of produced chitinase;the response surface test was used to determine the optimal conditions for chitinase production.[Result] The optimal conditions for chitinase production were：8% of glucose,5% of beef extract and 0.07% of MgSO4,and the activity of chitinase reached the maximal value（6.86 U）under these conditions.[Conclusion] The study improved the activity of chitinase produced by strain G-254 and provided good foundation for industrial production.展开更多
[Objective] To study the cocoon traits of wild silkworm descendants. [Method] In the selective breeding of domesticated raising wild silkworm and wild silkworm descendants, investigation on the traits of the built coc...[Objective] To study the cocoon traits of wild silkworm descendants. [Method] In the selective breeding of domesticated raising wild silkworm and wild silkworm descendants, investigation on the traits of the built cocoons was carried out. [Result] The pointed traits of cocoons displayed obviously in the wild silkworm descendants, its pointed parts were consistent with the rear part of silkworm chrysalis, and the female silkworm has slight difference, indicating the silkworm co- coon pointed trait was hereditary. [Conclusion] This study provided references for the study of silkworm cocoon traits of wild silkworm descendant and guides the selective breeding of silkworm variety.展开更多
Metabolism of hydrogen peroxide in the course of embryonic development ofsilkworm (variety Guang) was determined by using colorimetric analysis and oxygen electrodemethod. The results indicated that: 1) In the course ...Metabolism of hydrogen peroxide in the course of embryonic development ofsilkworm (variety Guang) was determined by using colorimetric analysis and oxygen electrodemethod. The results indicated that: 1) In the course of fertilization (0-4 h after egg laying), thelevel of H_2O_2 content reached its peak value at 2.5 h of the developmental course and the activity ofsuperoxidase dismutase (SOD) was at higher level while the activity of catalase (CAT) at the lowestcorrespondingly; 2) The H_2O_2 content in embryo, in which the diapause of eggs was being relievedthrough treatment with hydrochloric acid on time in the course of embryonic development, wassignificantly higher than that of diapause eggs except the lower level showed in the embryo whenthe development of it went on for 168~216 h and the activity of SOD reached, lower and higher,tWo peaks in 72 and 168 h after egg-laying, respectively, and was significantly higher in late stagewhile the activity of CAT was shown with a stable level in the period of 72-192 h after egg-laying,and, after then, a rapid rising occurred in the embryo. The level of the CAT activity in embryowas shown significantly lower than that in diapause eggs in early period and higher in late stage ofegg development; 3) In the course of formation of diapause in eggs, the level of H_2O_2contentchanged smoothly and the activity of SOD changed vigorously in early period, and kept stable statelater; and the CAT activity increased gradually; while in the course of relief of diapause under ontime-treatment with hydrochloric acid, the level of H_2O_2 was significantly higher than that indiapause eggs and the SOD activity displayed a new peak value and significantly rose in later stage,while the activity of CAT in relieving embryo from diapause was signincantly lower than that indiapause eggs. Combining the results obtained in other researches with those from ours mentionedabove, we suggest that the metabolism of H_2O_2 might be of importance in the courses of formationand relief of diapause in silkworm eggs. Maybe the esterase A4 timer hypothesis and themicropylar barrier to oxygen hypothesis could be integrated for explanation of the course offormation and relief of diapause in silkworm eggs.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 700-800μg/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 Young Elite Scientist Sponsorship Program by CAST (2015QNRC001)the Earmarked Fund for Modern Agro-industry Technology Research System
文摘Silkworm silks have been widely used in a variety of fields due to their sensuousness, luster and excellent mechanical properties. Researchers have paid special attention in improving the mechanical properties of silks. In this work,Bombyx mori larval silkworms are injected with graphene quantum dots(GQDs) through a vascular injection to enhance mechanical properties of the silkworm silks. The GQDs can be incorporated into the silkworm silk gland easily due to hemolymph circulation and influence the spinning process of silkworm. The breaking strength, elongation at break and toughness modulus of the silks increase by 2.74, 1.33 and 3.62 times, respectively, by injecting per individual with 0.6 μg GQDs. Wide-angle X-ray scattering indicates that the size ofβ-sheet nanocrystals in GQDs-silks is smaller than that in control-silks. Infrared spectra suggest that GQDs confine the conformation transition of silk fibroin to β-sheet from random coil/α-helix, and the change of the size and content of β-sheet may be the reason for the improvement of the mechanical properties. The toxicity and safety limit of GQDs incorporated into each silkworm is also evaluated, and the results show that the upmost dose of GQDs per silkworm is30.0 μg. The successful obtainment of reinforced silks by in vivo uptake of GQDs provides a promising route to produce high-strength silks.
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 Natural Science Foundation of China(32270458,32070411,2023A1515010657)State Key Laboratory of Resource Insects(SKLSGB-ORP202209)。
文摘The domesticated silkworm(Bombyx mori)has evolved a highly efficient nitrogen utilization system to support silk production.The silk glands play a pleiotropic role in sequestering nitrogen resources for silk synthesis,mitigating aminoacidemia by assimilating free amino acids,and reallocating nitrogen during metamorphosis through programmed cell death.However,the specific functions of nitrogen metabolism-related genes in this process remain unclear.Using CRISPR/Cas9-based gene editing,mutations were generated in glutamine synthetase(GS),glutamate synthetase(GOGAT),asparagine synthetase(AS),glutamate dehydrogenase(GDH)and glutamate oxaloacetate transaminase 1(GOT1).Disruption of GS,GOGAT,and AS consistently reduced silkworm cocoon and pupal weight and significantly down-regulated silk protein gene transcription,whereas GOT1 mutation had no such effect.GOGAT mutants exhibited abnormally enlarged silk glands,whereas GS and AS mutants showed delayed programmed cell death in the silk glands.In contrast,GOT1 mutants displayed normal silk gland morphology but were consistently smaller.Disruption of GS,GOGAT,and AS led to more extensive transcriptional changes,including altered expression of transcription factors in the silk glands,compared with GOT1 mutants.Both GS and GOGAT mutants exhibited up-regulation of AS and GDH,while only GOGAT mutants displayed elevated AS enzymatic activity,suggesting that GOGAT may compete with AS for glutamine in the silk glands to support silk protein synthesis.AS mutants showed significantly elevated GOT activity and up-regulation of several metabolic pathways,indicating that AS may functionally interact with GOT in regulating both silk gland development and programmed cell death during metamorphosis.
基金supported by the National Key Research and Development Program of China(2023YFF1103802)。
文摘The anti-inflammatory properties of silkworm pupa peptide(SPP)have been recognized for their potential benefits in colitis treatment.However,the underlying mechanism of SPP in colitis animal models remains unclear.The objective of our work was to investigate the improving effect and the mechanism of action of SPP on a mouse model of dextran sulfate sodium(DSS)-induced colitis.The findings suggested that SPP effectively eased ulcerative colitis(UC)symptoms in mice by decreasing disease activity index,ameliorating histopathological injury,and decreasing serum and colonic markers of inflammation.In addition,our research findings demonstrated that SPP restored intestinal barrier function by increasing the production of tight junction proteins such as zonula occludens-1(ZO-1),claudin-1,claudin-3,occludin,and adherens junction protein E-cadherin1.Further,SPP supplementation enhanced the concentration of short-chain fatty acids and positively altered the makeup of the gut bacteria in the mice's gut.These findings underscore SPP's ability to slow the progression of colitis and point to its possible use as a functional component in dietary supplements for the prevention of early-stage colitis.
文摘[ Objective] The aim of this study was to investigate effects of various inducers on the expression of cytochrome P450 CYP305 B1 V1 Gene in different tissues of wild mulberry silkworm. [ Method] Referring to the mRNA sequence of CYP305 B1 V1 Gene published in GenBank for wild mulberry silkworm, one pair of primers was designed, and the expression of cytochrome P450 CYP305 B1 V1 Gene in different tissues of wild mulberry silkworm treated by NaF, rutin, cypermethrin and ecdysone was also analyzed by the semi - quantitative RT - PCR. Furthermore, homology comparison and phylogenetic analysis for amino acid sequences of this gene were studied. [ Result] Rutin, cypermethrin and NaF had effects on the expression of P450 CYP305 B1 V1 Gene in different tissues of wild mulberry silkworm, while ecdysone had no significant effect. Homology comparison for amino acids indicated that the amino acid sequence of this gene was the most similar to that of CYP305 B1 gene in Bombyx mori with 100% amino acid identity, and highly similar to those of Tribolium casmneum CYP305A1, Apis mellifera CYP305A1, Drosophi- la melanogaster CYP305A1, Anopheles gambiae CYP305A2and Culex pipiens quinquefasciatus CYP2LI. [ Conclusion] CYP305 B1 V1 Gene of wild mulberry silkworm is likely to mainly take part in the metabolism of exogenous compounds, which is of great significance for revealing the function of cytochrome P450 and the metabolic mechanism of different drugs.
基金Supported by Agricultural Key Project of Guangdong Province(2007A0201000043)Key Bidding Projects in Key Fields of Guangdong and Hongkong(2006A25001002)Special Fund for the Construction of National Modern Agro-industry Technology System~~
文摘[Objective] The research aimed to obtain an effectively-decomposing strain of silkworm chrysalis protein and discuss its enzymatic properties.[Method] The effectively-decomposing bacteria of protein was isolated from the decayed silkworm chrysalis by using dilution plate and its enzymatic properties were tested after primary screening and second screening.The enzyme activity was determined and the intermediate and small molecule protein content in silkworm chrysalis was measured after solid-state fermentati...
基金Supported by Jiangsu High-tech projects(BG2007322) "Good feature of new varieties of Silkworm BreedingPh.D., University of Jiangsu Science and Technology Fund~~
文摘[Objective] The study aimed to provide theoretical basis for development and application of molecular marker breeding technique to obtain Bombyx mori near-isogenic lines （NILs）. [Method] Thermotolerance gene was introduced into sensitive variety Ou17 by developing NILs and recurrent backcross,then through six generations of backcross,thermotolerance-assisted selection,and two generations of self-cross. [Result] Bombyx mori NILs carrying thermotolerance gene （new germplasm） were produced. Meanwhile,thermotolerance level of progenies of each backcross and molecular markers of NILs were determined,and then attempts were made to produce practical thermotolerance hybrids by using thermotolerance varieties whose thermotolerance gene is linked to SSR markers. [Conclusion] The study successfully construct thermotolerance NILs,monitor thermotolerance level and breeding results of progenies of each backcross,and determine molecular marker of NILs.
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.
文摘A simple and green technique has been developed to prepare hierarchical biomorphic ZrO2- CeO2, using silkworm silk as the template. Different from traditional immersion technics, the whole synthesis process depends more on the restriction or direction functions of the silkworm silk template. The analytic results showed that ZrO2-CeO2 exhibited a well-crystallized hierarchically interwoven hollow fiber structure with 16-28 μm in diameter. The grain size of the sample calcined at 800 ℃ was about 14 nm. Consequently, the interwoven meshwork at three dimensions is formed due to the direction of biotemplate. The action mechanism is summarily discussed here. It may bring the biomorphic ZrO2-CeO2 nanomaterials with hierarchical interwoven structures to more applications, such as catalysts.
基金Supported by Science and Technology Support Project of Guangdong Academy of Agricultural Science and Technology(07-Supporting-04)Agricultural Research Projects in Guangdong Province (2007A0201000043)Earmarked Fund for Modern Agro-Industry Technology Research System of China~~
文摘[Objective] The aim of this study was to optimize the conditions of chitinase-produce strains.[Method] A kind of screened chitinase-produce strain G-254 was habituated cultured,and then the single factor experiment was carried out to explore the effects of different carbon source,nitrogen source and inorganic salt on the activity of produced chitinase;the response surface test was used to determine the optimal conditions for chitinase production.[Result] The optimal conditions for chitinase production were：8% of glucose,5% of beef extract and 0.07% of MgSO4,and the activity of chitinase reached the maximal value（6.86 U）under these conditions.[Conclusion] The study improved the activity of chitinase produced by strain G-254 and provided good foundation for industrial production.
基金Supported by the Agricultural Fund Project of Ministry of Science and Technology(Y0415)the China Agriculture Research System(Sericulture)~~
文摘[Objective] To study the cocoon traits of wild silkworm descendants. [Method] In the selective breeding of domesticated raising wild silkworm and wild silkworm descendants, investigation on the traits of the built cocoons was carried out. [Result] The pointed traits of cocoons displayed obviously in the wild silkworm descendants, its pointed parts were consistent with the rear part of silkworm chrysalis, and the female silkworm has slight difference, indicating the silkworm co- coon pointed trait was hereditary. [Conclusion] This study provided references for the study of silkworm cocoon traits of wild silkworm descendant and guides the selective breeding of silkworm variety.
文摘Metabolism of hydrogen peroxide in the course of embryonic development ofsilkworm (variety Guang) was determined by using colorimetric analysis and oxygen electrodemethod. The results indicated that: 1) In the course of fertilization (0-4 h after egg laying), thelevel of H_2O_2 content reached its peak value at 2.5 h of the developmental course and the activity ofsuperoxidase dismutase (SOD) was at higher level while the activity of catalase (CAT) at the lowestcorrespondingly; 2) The H_2O_2 content in embryo, in which the diapause of eggs was being relievedthrough treatment with hydrochloric acid on time in the course of embryonic development, wassignificantly higher than that of diapause eggs except the lower level showed in the embryo whenthe development of it went on for 168~216 h and the activity of SOD reached, lower and higher,tWo peaks in 72 and 168 h after egg-laying, respectively, and was significantly higher in late stagewhile the activity of CAT was shown with a stable level in the period of 72-192 h after egg-laying,and, after then, a rapid rising occurred in the embryo. The level of the CAT activity in embryowas shown significantly lower than that in diapause eggs in early period and higher in late stage ofegg development; 3) In the course of formation of diapause in eggs, the level of H_2O_2contentchanged smoothly and the activity of SOD changed vigorously in early period, and kept stable statelater; and the CAT activity increased gradually; while in the course of relief of diapause under ontime-treatment with hydrochloric acid, the level of H_2O_2 was significantly higher than that indiapause eggs and the SOD activity displayed a new peak value and significantly rose in later stage,while the activity of CAT in relieving embryo from diapause was signincantly lower than that indiapause eggs. Combining the results obtained in other researches with those from ours mentionedabove, we suggest that the metabolism of H_2O_2 might be of importance in the courses of formationand relief of diapause in silkworm eggs. Maybe the esterase A4 timer hypothesis and themicropylar barrier to oxygen hypothesis could be integrated for explanation of the course offormation and relief of diapause in silkworm eggs.
