The Ability to Digest Cellulose Can Significantly Improve the Growth and Development of Silkworms.

Cellulose is essential in the growth and development of herbivores. However, its limited utilization by herbivores is a key factor restricting their feed conversion rates. Cellulase can hydrolyze cellulose into glucose, and the addition of exogenous cellulase preparations to feed is an effective method for improving the cellulose utilization rate of ruminants.

Complete BmFib-L knockout reveals its indispensable role in silk fiber formation.

Silkworm (Bombyx mori), belonging to the order Lepidoptera, is an important model insect for economic and scientific research. The capacity of the silkworm to secrete robust silk renders it a valuable economic resource, while its biological characteristics offer insights into a number of scientific disciplines. Despite the extensive research conducted to elucidate the mechanisms of silk secretion, many aspects remain unclear.

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.

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 (BmRelish) 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.

An Efficient Biosynthetic System for Developing Functional Silk Fibroin-Based Biomaterials.

Long historical evolution and domestication endow silkworms with the super ability to synthesize and secrete massive silk proteins using silk glands. The major component of this secretion consists of silk fibroin, considered a promising biomaterial for tissue repairs and engineering. To further expand the utility of this unique protein, there is a continuing need for silk fibroin functionalization.

Fabrication of a transforming growth factor β1 functionalized silk sericin hydrogel through genetical engineering to repair alveolar bone defects in rabbit.

Cleft palate is one of the most prevalent congenital craniofacial birth defects in human congenital facial anomaly. Severe cleft palate is usually accompanied by alveolar bone defects (ABDs). Growth factors (GFs) are considered as desirable opportunity to promote the craniofacial healing post the surgery.

The T2T Genome of the Domesticated Silkworm .

Genome sequences contain the fundamental genetic information that largely determines the biology of a species. Over the past 20 years, advancements in high-throughput sequencing technologies and bioinformatics tools have matured, facilitating genome assembly and ushering in the telomere-to-telomere (T2T) era. is renowned as a silk-producing insect and serves as an important model organism extensively studied across various fields of biology.

Downregulation of transcription factor promoted nucleopolyhedrovirus replication in .

The Janus kinase/signal transducer and activator of transcription (JAK/STAT) signaling pathway plays a crucial role in the viral immune processes of organisms, with STAT being a key transcription factor downstream in this pathway. The gene of has two splicing forms, named and . This study compared the effects of the two splicing forms on nucleopolyhedrovirus (BmNPV) infection through cell-level interference and further explored whether participates in the immune response to BmNPV infection via transgenic intervention at the individual level.

GC-MS-based metabonomic analysis of silkworm haemolymph reveals four-stage metabolic responses to nucleopolyhedrovirus infection.

Silkworm, Bombyx mori, an economically significant insect, plays a crucial role in silk production. However, silkworm breeding is highly susceptible to various pathogens, particularly the Bombyx mori nucleopolyhedrovirus (BmNPV), which poses a serious threat. Recent metabonomic studies have provided insights into the metabolic changes associated with BmNPV infection.

A mutation in the Bombyx mori BmSPI51 gene results in alterations protein abundance in cocoon and unveils compensatory mechanism of silk gland proteinase inhibitors.

Proteinase inhibitors constitute a significant component of Lepidoptera cocoon. BmSPI51 is the most abundant protease inhibitors in silkworm cocoons. In this study, we aimed to elucidate the biological function of BmSPI51 in both the silkworm silk gland and cocoon formation.

Schlank orchestrates insect developmental transition by switching H3K27 acetylation to trimethylation in the prothoracic gland.

Insect developmental transitions are precisely coordinated by ecdysone and juvenile hormone (JH). We previously revealed that accumulated H3K27 trimethylation (H3K27me3) at the locus encoding JH signal transducer Hairy is involved in the larval-pupal transition in insects, but the underlying mechanism remains to be fully defined. Here, we show in and that Rpd3-mediated H3K27 deacetylation in the prothoracic gland during the last larval instar promotes ecdysone biosynthesis and the larval-pupal transition by enabling H3K27me3 accumulation at the locus to induce its transcriptional repression.

Insights into the activation mechanism of Bm-CPA: Implications for insect molting regulation.

Carboxypeptidase A has been found across various animal species, yet its activation mechanism during the insect molting process remains elusive. Our study specifically delved into the activation mechanism of carboxypeptidase A (Bm-CPA), identified in Bombyx mori's molting fluid during metamorphosis. Initially, western blotting identified two forms of Bm-CPA, 65 kDa and 54 kDa, in the epidermis of silkworms during the molting stage.

Fibroinase plays a vital role in silk gland degeneration by regulating autophagy and apoptosis in the silkworm, Bombyx mori.

The silkworm is an incredibly valuable insect that produces silk through its silk gland. Within this organ, Fibroinase has been identified and named due to its ability to fibroin degradation. The expression of Fibroinase in the silk gland significantly increases during the larval-pupal stage, which might be associated with the degeneration of the silk gland.

STAT transcription factor is indispensable for oogenesis in silkworm.

Signal Transducer and Activator of Transcription (STAT) proteins represent a critical transcription factor family with multifaceted roles in diverse fundamental eukaryotic processes. In Drosophila, STAT exerts a pivotal regulatory influence on oogenesis, governing the early differentiation of follicular cells and ensuring proper encapsulation of germ-line cells. However, the role of STAT in egg development in silkworms remains unknown.

A cryptic homotypic interaction motif of insect STING is required for its antiviral signaling.

Stimulator of interferon genes (STING) mediates innate immune response upon binding to cyclic GMP-AMP (cGAMP). It recruits tank-binding kinase 1 (TBK1) and transcription factor interferon regulatory factor 3 (IRF3) through its C-terminal tail and facilitates TBK1-dependent phosphorylation of IRF3 via forming STING polymers in mammalian cells. However, the mechanism behind STING-mediated activation of NF-κB transcription factor, Relish, in insect cells is unknown.

Effects of poly (ADP-ribose) polymerase 1 (PARP1) on silk proteins in the silkworm, Bombyx mori.

Animal silk is economically important, while silk secretion is a complex and subtle mechanism regulated by many genes. We identified the poly (ADP-ribose) polymerase (PARP1) gene of the silkworm and successfully cloned its coding sequence (CDS) sequence. Using clustered regularly interspaced short palindromic repeat (CRISPR/Cas9) technology, we screened single guide RNA (sgRNA) with high knockout efficiency by cellular experiments and obtained PARP1 mutants by knocking out the PARP1 gene of the silkworm at the individual level.

Mutation in the Bombyx mori BmGMC2 gene impacts silk production and silk protein synthesis.

Silk is a natural protein fiber that is predominantly comprised of fibroin and sericin. In addition, it contains seroins, protease inhibitors, enzymes, and other proteins. We found an ecdysone oxidase BmGMC2, notably, which is specifically and highly expressed only in the silk glands of silkworms (Bombyx mori L.

A strategy for improving silk yield and organ size in silk-producing insects.

Insect silks possess excellent biodegradability, biocompatibility and mechanical properties, and have numerous applications in biomedicine and tissue engineering. However, the application of silk fiber is hindered by its limited supply, especially from non-domesticated insects. In the present study, the silk yield and organ size of Bombyx mori were significantly improved through genetic manipulation of the target of rapamycin complex 1 (TORC1) pathway components.

Fatty Acid Desaturase , Suppressed in the Salivary Glands by Domestication, is Involved in Regulation of Food Intake in Silkworms.

Understanding the evolutionary genetics of food intake regulation in domesticated animals has relevance to evolutionary biology, animal improvement, and obesity treatment. Here, we observed that the fatty acid desaturase gene (), which regulates food intake, is suppressed in domesticated silkworms, but expressed in the salivary glands of the wild silkworm . The content of its catalytic product, -vaccenic acid, was related to the expression levels of in the salivary glands of domesticated and wild silkworm strains.

Developmental and nuclear proteomic signatures characterize the temporal regulation of fibroin synthesis during the last molting-feeding transition of silkworm.

Silkworm fibroins are natural proteinaceous macromolecules and provide core mechanical properties to silk fibers. The synthesis process of fibroins is posterior silk gland (PSG)-exclusive and appears active at the feeding stage and inactive at the molting stage. However, the molecular mechanisms controlling it remain elusive.

Ectopic expression of BmeryCA in Bombyx mori increases silk yield and mechanical properties by altering the pH of posterior silk gland.

The silk glands are the specialized tissue where silk protein synthesis, secretion, and conformational transitions take place, with pH playing a critical role in both silk protein synthesis and fiber formation. In the present study, we have identified erythrocyte carbonic anhydrase (BmeryCA) belonging to the α-CA class in the silk gland, which is a Zn dependent metalloenzyme capable of efficiently and reversibly catalyzing the hydrated reaction of CO to HCO, thus participating in the regulation of acid-base balance. Multiple sequence alignments revealed that the active site of BmeryCA was highly conserved.

High-Throughput Screening of PAM-Flexible Cas9 Variants for Expanded Genome Editing in the Silkworm ().

Genome editing provides novel opportunities for the precise genome engineering of diverse organisms. Significant progress has been made in the development of genome-editing tools for () in recent years. Among these, CRISPR/Cas9, which is currently the most commonly used system in lepidopteran insects, recognizes NGG protospacer adjacent motif (PAM) sequences within the target locus.