Silkworm Larvae Research Articles

Elasticity of trachea in the silkworm: A role of gene BmMuc91C.

Respiration is a vital process essential for organism survival, with most terrestrial insects relying on a sophisticated tubular tracheal network. In the current study, a gene with repetitive sequence was identified within the silkworm genome. Designated as BmMuc91C, it contains a dozen repeated motifs "PSSSYGAPX" and "GGYSSGGX" in its sequence. BmMuc91C exhibits specific expression in the tracheal system of silkworm larvae, with significantly higher expression levels during the molting stage. Overexpression of BmMuc91C in individual silkworms resulted in a marked increase in tracheal diameter, particularly during the molting stage. Immunofluorescence staining using a BmMuc91C antibody revealed a noticeable thickening of the apical extracellular matrix in the trachea. Tensile testing confirmed a considerable enhancement in tracheal elasticity. Additionally, a BmMuc91C mutation strain of silkworms was generated using the clustered regularly interspaced short palindromic repeats (CRISPR) / CRISPR-associated nuclease 9 system. Although no significant differences were observed in the growth, development, and molting of BmMuc91C mutant silkworms, mechanical tests demonstrated a decrease in tracheal elasticity. Transcriptomic techniques revealed that a significant number of cuticular and chitin-binding proteins were among the differentially expressed genes between mutant and wild-type silkworms. Furthermore, the recombined BmMuc91C protein was successfully expressed using the Escherichia coli system. Cross-linking experiments with horseradish peroxidase demonstrated the formation of macromolecular complexes of BmMuc91C, which exhibited spontaneous luminescent properties under ultraviolet light. This research sheds light on the role of elastic proteins in insect tracheae and provides valuable insights for the development of elastic biomaterials.

Successful oral RNA interference efficiency in the silkworm Bombyx mori through nanoparticle-shielded dsRNA delivery.

Double-stranded RNA (dsRNA) mediated RNA interference (RNAi) is a tool in functional gene study and pest control. However, RNAi efficiency in Lepidoptera is low compared to the RNAi sensitive Coleoptera. Previous studies on RNAi in the silkworm Bombyx mori, the lepidopteran model insect, were performed by injection only. Successful oral RNAi in the silkworm has never been reported yet. This study aims to develop a successful oral dsRNA delivery method to the silkworm larvae. Chitosan is an economical and biodegradable polymer. Chitosan/dsRNA nanoparticles were prepared by self-assembly. These nanoparticles were found to be stable when incubated in the midgut juice of the silkworm larvae, whereas naked dsRNA underwent complete degradation. Chitosan/dsRNA nanoparticles targeting various immune genes in oral administration to the silkworm larvae mediated significant knockdown of gene transcript. This silencing effect resulted in smaller larvae and cocoons when the silkworms were fed with Chitosan/dsRNA nanoparticles targeting BmToll9-2 gene, indicating that immune genes might be used as targets in pest control. Optimization of the chitosan/dsRNA nanoparticles maintained an RNAi effect from 3-5 days. The efficient RNAi was due to the persistence of nanoparticle-shielded dsRNA in the larvae. The above findings contribute to the first oral RNAi report in the silkworm, which facilitates the application of RNAi in insects and oral RNAi in pest control.

A novel digestive protease chymotrypsin-like serine contributes to anti-BmNPV activity in silkworm (Bombyxmori).

Serine proteases (SPs) are important proteases in the digestive system of lepidopteran insects. They play important roles in protein digestion, coagulation, signal transduction, hormone activation, inflammation and development. Blood-borne pyosis caused by Bombyx mori nuclear polyhedrosis virus (BmNPV) has caused serious harm to sericulture. At present, the scientific problems of BmNPV infection and silkworm resistance to BmNPV infection have been the focus of many scientists, but the molecular mechanism needs further research and exploration. Based on the results of label-free quantitative protein proteomics of the midgut digestive juice of different resistant strains in our laboratory, we successfully screened a differentially expressed candidate protein (DEP), B. mori chymotrypsin-like serine protease (BmCLSP), and comprehensively analyzed the biological characteristics and anti-BmNPV function of BmCLSP. The open reading frame (ORF) of BmCLSP is 891 bp, encoding 296 amino acid residues. The analysis of the domain structure showed that there was a signal peptide and a trypsin-like serine protease domain, Tryp_SPC, in the BmCLSP protein. Semi-quantitative and real-time fluorescence quantitative PCR analysis showed that the BmCLSP gene was highly expressed in the fifth instar larvae of silkworm, and specifically expressed in the midgut. The expression level of BmCLSP in the BmNPV resistant strain A35 was higher than that in the sensitive strain P50. Virus amplification analysis showed that the relative expression level of VP39 was significantly lower than that of the control group after infection of silkworm larvae and BmN cells with BmNPV treated with recombinant BmCLSP at an appropriate concentration. Furthermore, our overexpression of BmCLSP in BmN cells significantly inhibited the expansion of BmNPV. In summary, the results of this study indicate that BmCLSP has anti-BmNPV activity in silkworm, and can significantly inhibit the proliferation of BmNPV in silkworm. It offers a promising avenue for silkworm anti-virus breeding.

Influence of Phyllanthus emblica Extract Fortified Mulberry Leaves on the Commercial Parameters of the Silkworm Bombyx mori. L

In recent years, a variety of plant extracts in varying concentrations have been utilized in commercial silk farming to observed their effects on commercial parameters of Bombyx mori L. In the present investigation, the effects of ethanolic extract of Phyllanthus emblica Linn. was studied with different concentrations on the larvae of silkworm, Bombyx mori L. The results show increasing trend in some important commercial parameters. The effective increase in single cocoon weight, filament length and filament weight was observed with the use of 1: 2, 1: 4 and 1: 8 concentrations of Phyllanthus emblica Linn.

Effects of Novaluron Exposure on the Oviposition and Expression of Ovarian Development Related Genes in Silkworm, Bombyx mori (Lepidoptera: Bombycidae)

Bombyx mori (Lepidoptera: Bombycidae) is an important economic insect, which mainly feeds on mulberry leaves and is widely used in many research fields. The growth and development of silkworm larvae are easily affected by the use of chemical insecticides such as novaluron, a benzoylurea insecticide. However, the effect of novaluron exposure on the reproduction of silkworms has not yet been studied. In this study, the effect of trace novaluron on the oviposition of silkworms and histopathological changes were first evaluated, and then the gene expression level changes after novaluron exposure were also determined by employing qRT-PCR. It was found that the number of eggs and the hatching rate of eggs in silkworms decreased significantly after feeding on leaves with a trace amount of novaluron (p ≤ 0.01). Furthermore, novaluron exposure could affect the development of ovary tissue by reducing the number of oocytes and oogonia in the ovaries of silkworms fed with novaluron. In addition, the transcription levels of genes related to ovary development (Vg, Ovo, Otu, Sxl-S and Sxl-L) and hormone regulation (EcR and JHBP2) showed varying degrees of downregulation at 24 h, 48 h, and 72 h after novaluron treatment (p ≤ 0.05). Therefore, we speculated that novaluron can affect the energy metabolism, ovary development, and egg formation of silkworms, thus leading to reproductive disorders of silkworms after novaluron exposure.

Antiviral activity of red fluorescent proteins in silkworm, Bombyx mori L.

Silkworm is an important economic insect in the textile industry for the production of silk. During its larval period, it suffers from various types of diseases viz., fungal, viral, bacterial and protozoan which hamper its growth and development and negatively impact the raw silk production. To fight these pathogens, different types of proteins have been found in the silkworm larva. Among these proteins, red fluorescent proteins (RFPs) possess antiviral activity, found in the digestive juice of the midgut of silkworm larvae. These RFPs are found to be more effective against Bombyx mori L. nucleopolyhedrosis virus (BmNPV), which is the causal agent of the most dreadful disease known as Grasserie. The RFP is synthesised in the presence of light after silkworms are fed on fresh mulberry leaves having absorbance peaks (280 and 605 nm) wave length.

The mortality of Bombyx mori larvae challenged by BmNPV is reduced when supplemented with Lactobacillus acidophilus bacteria

ObjectiveBombyx mori nucleopolyhedrovirus (BmNPV) causes grasserie with severe effects in Thai strains of the silkworm Bombyx mori. The aim of this study was to investigate the effect of probiotic supplementation on the survival of silkworm larvae challenged with BmNPV.ResultsSilkworm larvae of the Thai polyvoltine strain Samrong was supplemented with commercial probiotic bacteria, Lactobacillus acidophilus, on the second day of the 2nd, 3rd, 4th, and 5th instar. When challenged with BmNPV on the second day of the 4th instar, the survival ratio was 92% for larvae supplemented with L. acidophilus as compared to 56% for larvae without L. acidophilus supplementation. For the larvae that survived until pupation, we determined the growth characters cocooning ratio, larval weight, and pupation ratio, and the economic characters cocoon shell weight and cocoon weight. Growth characters were significantly lower in larvae infected with BmNPV as compared to infected larvae receiving probiotics.

16S rRNA Sequencing Analysis Uncovers Dose-Dependent Cupric Chloride Effects on Silkworm Gut Microbiome Composition and Diversity.

Copper-based pesticides are extensively used in agriculture, yet their impacts on beneficial insects remain poorly understood. Here, we investigate how cupric chloride exposure affects the gut microbiome of Bombyx mori, a model organism crucial for silk production. Using 16S rRNA sequencing, we analyzed the gut bacterial communities of fifth-instar silkworm larvae exposed to different concentrations of cupric chloride (0, 4, and 8 g/kg) in an artificial diet. The high-dose exposure dramatically altered the microbial diversity and community structure, where the Bacteroidota abundance decreased from 50.43% to 23.50%, while Firmicutes increased from 0.93% to 18.92%. A network analysis revealed complex interactions between the bacterial genera, with Proteobacteria and Firmicutes emerging as key players in the community response to copper stress. The functional prediction indicated significant shifts in metabolic pathways and genetic information processing in the high-dose group. Notably, the low-dose treatment induced minimal changes in both the taxonomic composition and predicted functions, suggesting a threshold effect in the microbiome response to copper exposure. Our findings provide novel insights into how agricultural chemicals influence insect gut microbiota and highlight potential implications for silkworm health and silk production. This work contributes to understanding the ecological impacts of copper-based pesticides and may inform evidence-based policies for their use in sericulture regions.

An NF-κB-regulated cytokine enhances the antiviral resistance of silkworm, Bombyx mori.

Insect NF-κB-like factor, Relish, is activated by viral infection and induces the production of antiviral proteins. In this study, we performed a transcriptomic analysis of BmE cells expressing the active form of BmRelish (BmRelishact) and identified BmVago-like as the most strongly-induced secreted-protein. Expression of BmVago-like was specifically triggered by Bombyx mori Nucleo Polyhedro Virus (BmNPV) infection and regulated by BmSTING-BmRelish pathway. Incubating the fresh culture of cells with supernatant medium of BmVago-like expressing cells or recombinant BmVago-like protein (rBmVago-like) significantly increased antiviral resistance. On the contrary, reducing the expression of Bmvago-like by RNA interference (RNAi) in BmE cells as well as in silkworm larvae impaired antiviral response. Furthermore, we constructed transgenic silkworm line over-expressing BmVago-like (BmVago-likeOV) and found they had markedly lower viral load and higher survival rate after BmNPV infection compared with the wild-type control. Co-immunoprecipitation assay showed Bmintegrin β1 interacts with BmVago-like and it was involved in BmVago-like mediated antiviral response. Finally, we found the expression level of signalling molecules in the JAK-STAT pathway increased in rBmVago-like-treated cells and BmVago-likeOV silkworm larvae but decreased in RNAi-treated cells. In summary, our research uncovered an inducible antiviral response in silkworm mediated by cytokine BmVago-like, which is the downstream effector of BmSTING-BmRelish pathway and functions as an antiviral cytokine.

Comparative Physiological, Proteomic, and Metabolomic Insights into a Promising Low-Pruning Mulberry Cultivar for Silkworm Rearing.

Mulberry (Morus spp.) is an economically significant plant in the production of silk through feeding leaves to silkworm larvae. Traditional silkworm rearing is heavily labor-intensive, particularly in leaf collection, which leads to low efficiency and impedes the development of sericulture. Here, to assess the feasibility and effectiveness of a novel low-pruning mulberry cultivar, ZJ1, in the silkworm rearing industry, a comprehensive investigation integrating physiological, proteomic, and metabolomic analyses was conducted in comparison with the traditionally high-pruning cultivar, N14. The low-pruning mulberry variety ZJ1 exhibited a notable increase in annual leaf yield of 43.94%, along with a significant enrichment of serine and isoleucine contents, in contrast to those of the high-pruning variety N14. Through iTRAQ proteomics and LC-MS/MS metabolomics analyses, a total of 561 reduced and 803 increased differentially expressed proteins (DEPs), as well as 332 differential expressed metabolites (DEMs) in positive ions and 192 DEMs in negative ions, were identified in the ZJ1 group relative to the N14 group, respectively. The observed features in amino acid profiles and the enrichment of the sucrose-related metabolic pathway provided interesting insights for future endeavors in mulberry variety improvement and the optimization of silkworm diet formulations. Collectively, the low-pruning cultivar ZJ1, characterized by its rapid growth, high leaf productivity, and suitability for mechanized operations, is expected to be an efficient substitute in improving the future sericultural industry, especially in urbanized and industrialized regions.

Prohibitin 1 tethers lipid membranes and regulates OPA1-mediated membrane fusion.

Prohibitins (PHBs) are ubiquitously expressed proteins in the mitochondrial inner membrane (MIM) that provide membrane scaffolds for both mitochondrial proteins and phospholipids. Eukaryotic PHB complexes contain two highly homologous PHB subunits, PHB1 and PHB2, which are involved in various cellular processes, including metabolic control through the regulation of mitochondrial dynamics and integrity. Their mechanistic actions at the molecular level, however, particularly those of PHB1, remain poorly understood. To gain insight into the mechanistic actions of PHB1, we established an overexpression system for the full-length recombinant protein using silkworm larvae and characterized its biophysical properties in vitro. Using recombinant PHB1 proteoliposomes reconstituted into MIM-mimicking phospholipids, we found that PHB1 forms an oligomer via its carboxy-terminal coiled-coil region. A proline substitution into the PHB1 coiled-coil collapsed its well-ordered oligomeric state, and its destabilization correlated with mitochondrial morphologic defects. Negative-staining electron microscopy revealed that homotypic PHB1-PHB1 interactions via the coiled-coil also induced liposome tethering with remodeling of the lipid membrane structure. We clarified that PHB1 promotes membrane fusion mediated by optic atrophy 1 (OPA1), a key regulator of MIM fusion. Additionally, the presence of PHB1 reduces the dependency of lipids and OPA1 for completing the fusion process. Our in vitro study provides structural insight into how the mitochondrial scaffold plays a crucial role in regulating mitochondrial dynamics. Modulating the structure and/or function of PHB1 may offer new therapeutic potential, not only for mitochondrial dysfunction but also for other cell-related disorders.

Detection of Probiotic Bacteria Ligilactobacillus salivarius in the Midgut of Eri Silkworm (Samia ricini, donovan) Collected from Borduar, Assam

Background: Eri silkworm rearing, crucial to Assam’s economy, faces severe productivity threats from disease and crop loss. These challenges impact farmers’ livelihoods, highlighting the urgent need for innovative solutions to boost disease resistance and crop yield, ensuring the industry’s sustainability and profitability. Methods: The study investigated the detection of Lactobacillus species in the midgut of the Eri silkworm (Samia ricini, Donovan) collected from Borduar, Assam. The research involved identifying Ligilactobacillus salivarius in the midgut of 5th instar larvae of the Borduar ecorace of Eri silkworm. The larvae, reared separately on castor and kesseru host plants, were utilized for isolating Lactobacillus on MRS agar. Molecular identification of these isolates was achieved through 16S rRNA sequence analysis. Result: Ligilactobacillus salivarius, a species under the genus Lactobacillus, was identified for the first time in the midgut of Eri silkworm larvae. This bacterium is widely known as a potential probiotic in higher animals, particularly poultry, indicating its possible benefits for silkworm health. The discovery of Ligilactobacillus salivarius in silkworms paves the way for further research aimed at developing novel probiotics tailored specifically for the sericulture industry, potentially improving silkworm health and boosting productivity. Implementing these probiotics presents a promising solution to the challenges facing sericulture in Assam, offering enhanced disease resistance and crop yield.

β-fructofuranosidase regulation in silkworm silk gland development: Implications for silk gland morphogenesis and silk production

This study investigates the impact of β-fructofuranosidase (Bmsuc1) on the development of the silk gland in silkworms (Bombyx mori). Previous research shows that Bmsuc1 is highly expressed in the silk glands and may be involved in silk gland development and protein synthesis. However, the precise mechanism by which Bmsuc1 regulates silk gland development remains unclear. This study specifically used RNA interference to inhibit Bmsuc1 expression in silkworm larvae. The results revealed that silencing Bmsuc1 led to significant shortening of the anterior silk gland cells, left and right side size asymmetrical development of the middle silk gland, and alterations in cellular and inner membrane layer thickness. Furthermore, the glucose and fructose levels in the silk gland were significantly reduced, reducing cocoon weight. The interference of Bmsuc1 also triggers carbohydrate metabolism-related genes, beta-hexosaminidase subunit (HEXA-β) and glucose-6-phosphatase (G6Pase), which were upregulated. In addition, cell cycle-related genes, Cyclin E and cyclin-dependent kinase 2 (CDK2), were downregulated. These findings provide a new theoretical foundation for understanding the molecular mechanisms of silk gland development and offer insights into improving silk yield.

RNA-seq analysis of LPS-induced immune priming in silkworms (Bombyx mori) and the role of cytochrome P450 detoxification system in the process

While immune priming has been identified in many invertebrates, the intricate mechanisms that drive this process in insects continue to be a subject of mystery. In this study, we exposed silkworm larvae to varying doses of lipopolysaccharide (LPS) to induce immune priming and assessed their survival upon challenge with Bacillus thuringiensis (Bt). Transcriptome analysis was performed to identify differentially expressed genes (DEGs) associated with immune priming. The role of CYP450 genes in this process was further explored using RNA interference (RNAi) to knockdown CYP9E2 and CYP6K1, followed by measurements of detoxification enzyme activities and reactive oxygen species (ROS) levels. We found that LPS exposure significantly increased silkworm survival rates upon Bt challenge, indicating the induction of immune priming. Transcriptome analysis revealed 549 DEGs, including a large number involved in detoxification, immunity, and metabolism, suggesting a complex regulatory network that encompasses immune responses and metabolic pathways. Functional enrichment and gene set enrichment analysis (GSEA) highlighted the activation of immune signaling pathways and the involvement of detoxification processes. Knockdown of CYP9E2 and CYP6K1 resulted in increased ROS levels, decreased detoxification enzyme activities, and reduced survival rates post-Bt challenge, implicating the critical role of these genes in immune priming and detoxification. Our findings demonstrate that LPS-induced immune priming in silkworms involves the upregulation of CYP450 genes, which play a critical role in detoxification and immune response modulation. The study provides insights into the molecular mechanisms of immune priming in insects and highlights the potential of CYP9E2 and CYP6K1 as targets for enhancing disease resistance and pest management in insects.

BmE2F1 regulates endoreplication of silk gland cells in silkworm, Bombyx mori.

Endoreplication is particularly important in the context of silk protein synthesis within the silk gland cells of silkworms. Our previous research indicated that the BmE2F1 enhances the silk yield of silkworm cocoons, but the underlying molecular mechanism remains elusive. In this study, we employed RNA-sequencing to dissect the transcriptional profiles of silk glands in the wild-type Dazao silkworm strain and the overexpression (OE) silkworm strain with specific overexpression of the BmE2F1 gene in silk glands. Among the 1126 differentially expressed genes (DEGs), many related to DNA replication (endoreplication in silk glands of silkworm larvae) were significantly enriched. Quantitative real-time PCR confirmed that overexpression of BmE2F1 led to a substantial increase in the expression of 13 genes involved in the DNA replication pathway. Additionally, BmE2F1 upregulated the expression of BmCyclin E, a pivotal gene in the G/S phase transition. Moreover, BmE2F1 overexpression in silk glands significantly boosted DNA replication and concurrently increased the DNA content within silk glands. In conclusion, BmE2F1 regulates endoreplication in silk gland cells of silkworms through dual mechanisms: firstly, by enhancing the formation of the DNA replication complex; and secondly, by facilitating the cells' entry into the S phase.

Bmpallidin, encoding a subunit of the BLOC-1 complex, is involved in urate granules formation in silkworm integument.

The abnormal development of urate granules in silkworm larvae leads to translucent mutants with a distinct transparent phenotype. Studies on such mutants are expected to enhance current understanding of uric acid metabolism. The hoarfrost translucent (oh) mutant exhibits a mottled, translucent larval integument due to the presence of smaller and irregularly shaped urate granules compared to wild-type individuals. Uric acid content in the silkworm larval integuments is significantly lower in the oh mutant. Using positional cloning, we successfully narrowed a~180kb region linked to the oh locus and identified the candidate gene, Bmpallidin, encoding the biosynthesis of lysosome-related organelles complex 1 subunit 6. Three alternative splicing isoforms were identified; Only isoform II was predicted to translate normally and was drastically reduced at both mRNA and protein levels in the oh mutant. Conversely, the non-functional isoform III showed slightly increased expression in the mutant. An 860bp genomic sequence in the wild type was replaced by a 30bp sequence in the mutant. Knockdown of Bmpallidin induced a translucent phenotype in first-instar larvae. These findings conclude that Bmpallidin is responsible for the oh mutant phenotype and plays a crucial role in urate granules formation in silkworms.

The Mechanism of Damage to the Midgut by Low Concentration of Bacillus thuringiensis in the Silkworm, Bombyx mori.

Bacillus thuringiensis (Bt) has been extensively applied in agricultural pest management, posing a notable ecological risk to beneficial insects like Bombyx mori (silkworms). However, the toxicological mechanisms of Bt at low concentrations on silkworms remain largely unexplored. In this study, we determined the LC50 (96 h) of Bt for fifth-instar silkworm larvae to be 0.08 × 10-3 mg/L. Exposure to a sub-lethal concentration of Bt (1/2 LC50) led to significant reductions in body weight, pupal size, and the weights of both the whole cocoon and cocoon shell. Histopathological and ultrastructural examinations revealed that Bt exposure caused severe damage to the microvilli and epidermal cells of the midgut. Transcriptome sequencing of the midgut identified 290 differentially expressed genes (DEGs), with these genes predominantly involved in metabolic processes and apoptotic pathways. Notably, apoptosis-related genes such as Apaf-1 and Caspase-3 were upregulated by 5.08-fold and 1.27-fold, respectively. Further validation through TUNEL assays and Western blotting analysis confirmed a significant activation of apoptotic signaling. These findings suggested that low concentrations of Bt could trigger apoptotic pathways in the midgut of silkworm larvae, providing valuable insights into the toxicological evaluation of Bt at sub-lethal doses in insect species.

In Vivo Efficacy of a Nanoconjugated Glycopeptide Antibiotic in Silkworm Larvae Infected by Staphylococcus aureus.

To contrast the rapid spread of antibiotic resistance in bacteria, new alternative therapeutic options are urgently needed. The use of nanoparticles as carriers for clinically relevant antibiotics represents a promising solution to potentiate their efficacy. In this study, we used Bombyx mori larvae for the first time as an animal model for testing a nanoconjugated glycopeptide antibiotic (teicoplanin) against Staphylococcus aureus infection. B. mori larvae might thus replace the use of mammalian models for preclinical tests, in agreement with the European Parliament Directive 2010/63/EU. The curative effect of teicoplanin (a last resort antibiotic against Gram-positive bacterial pathogens) conjugated to iron oxide nanoparticles was assessed by monitoring the survival rate of the larvae and some immunological markers (i.e., hemocyte viability, phenoloxidase system activation, and lysozyme activity). Human physiological conditions of infection were reproduced by performing the experiments at 37 °C. In this condition, nanoconjugated teicoplanin cured the bacterial infection at the same antibiotic concentration of the free counterpart, blocking the insect immune response without causing mortality of silkworm larvae. These results demonstrate the value and robustness of the silkworm as an infection model for testing the in vivo efficacy of nanoconjugated antimicrobial molecules.

The role and mechanism of BmsPLA2-1-1 in the IMD pathway in silkworm, Bomybx mori

Lepidoptera are a major source of pests in agriculture and forestry, investigating the immune mechanisms of their model species, Bombyx mori, can provide valuable insights into improving pest management. Although the phospholipase A2 (PLA2) and immune deficiency (IMD) pathway have been extensively investigated, their relationship remains unclear. Here, we found that bacterial infection of silkworm larvae significantly upregulated BmsPLA2-1-1 expression and knockdown of BmRelish in the IMD pathway suppressed this response. Likewise, reducing BmsPLA2-1-1 expression significantly downregulated IMD pathway-related genes, including BmRelish, BmImd, and BmPGRP. In contrast, overexpression of BmsPLA2-1-1 significantly upregulated BmRelish and BmImd expression, suggesting a functional crosstalk between BmsPLA2-1-1 and the IMD pathway in silkworms. Additionally, BmsPLA2-1-1 interacted with BmHsp60, BmCNBP, BmCfp1, and BmPFD3. Reducing BmRelish resulted in decreased expression of BmHsp60, BmCfp1, and BmPFD3, but not BmCNBP, in infected larvae. Overexpression BmHsp60, BmCfp1, or BmPFD3 led to a significant upregulation of BmRelish and BmImd expression. These suggest that BmHsp60, BmCfp1, and BmPFD3 are involved in functional crosstalk between BmsPLA2-1-1 and the IMD pathway in silkworms. These findings demonstrate the functional crosstalk and mechanism between BmsPLA2-1-1 and the IMD pathway, revealing a new mechanism in the insect immune network.

Impact of Glutamine addition on Biological and Economical Characteristics of the Silkworm Larvae B. Mori L.

Impact of Glutamine addition on Biological and Economical Characteristics of the Silkworm Larvae B. Mori L.