Spin-Valley-Locked Electroluminescence for High-Performance Circularly Polarized Organic Light-Emitting Diodes.

Circularly polarized (CP) organic light-emitting diodes (OLEDs) have attracted attention in potential applications, including novel display and photonic technologies. However, conventional approaches cannot meet the requirements of device performance, such as high dissymmetry factor, high directionality, narrowband emission, simplified device structure, and low costs. Here, we demonstrate spin-valley-locked CP-OLEDs without chiral emitters but based on photonic spin-orbit coupling, where photons with opposite CP characteristics are emitted from different optical valleys. These spin-valley-locked OLEDs exhibit a narrowband emission of 16 nm, a high external quantum efficiency of 3.65%, a maximum luminance of near 98,000 cd/m2, and a gEL of up to 1.80, which are among the best performances of active single-crystal CP-OLEDs, achieved with a simple device structure. This strategy opens an avenue for practical applications toward three-dimensional displays and on-chip CP-OLEDs.

The inhibition of ecdysone signal pathway was the key of pyriproxyfen poisoning for silkworm, Bombyx mori.

Pyriproxyfen is a juvenile hormone-like pesticide. Once intake occurs, it leads to a series of poisoning characters consequences in silkworm, Bombyx mori (ID: 7091, Lepidoptera), such as non- cocooning, non-pupation, production of low-active eggs, and extended stages. However, the poisoning mechanism is still unclear. Here, silkworms were fed mulberry leaves soaked with different pyriproxyfen concentrations, and the heads were dissected for transcriptome analysis, while the hemolymph was used for determinations of ecdysone and juvenile hormone titers. As a result, after conjoint analysis of 3 feeding groups and a control group, 555 differentially expressed genes (DEGs) were obtained, which were mainly involved in hormone metabolism, glycometabolism and protein metabolism. Meanwhile, 119 genes were significantly correlated with the pyriproxyfen concentrations, and they were mainly involved in drug metabolism and glycometabolism. The ecdysone titers in several feeding groups were significantly lower than those of the control group, while juvenile hormone was not detected in all groups, including the control and feeding groups. Correspondingly, due to activation of the juvenile hormone signaling pathway by pyriproxyfen, key genes in the ecdysone synthesis pathway were downregulated, and a large number of downstream genes were up- or downregulated. In addition, nearly all genes in the detoxification pathway were upregulated. These results suggested that, affected by the juvenile hormone signaling pathway, ecdysone titers decreased and further affected a series of downstream processes, and this was the key reason for pyriproxyfen poisoning in silkworm, B. mori, which could lay a foundation for the study of pyriproxyfen resistance in silkworm.

Silver-catalyzed decarboxylative radical allylation of α,α-difluoroarylacetic acids for the construction of CF2-allyl bonds.

An efficient silver-catalyzed method of decarboxylative radical allylation of α,α-difluoroarylacetic acids to build CF2-allyl bonds has been developed. Using allylsulfone as an allyl donor, α,α-difluorine substituted arylacetic acids bearing various functional groups are successfully allylated to access a series of 3-(α,α-difluorobenzyl)-1-propylene compounds in moderate to excellent yields in aqueous CH3CN solution under the mild conditions. Experimental studies disclosed that the α-fluorine substitution of arylacetic acid has a great influence on free radical activity and reactivity.

Compensatory effects of other olfactory genes after CRISPR/cas9 editing of BmOR56 in silkworm, Bombyx mori.

Bombyx mori is an oligophagous economic insect. Cis-Jasmone is one of the main substances in mulberry leaf that attract silkworm for feeding and BmOR56 is its receptor. Potential interaction ways between BmOR56 and cis-Jasmone were explored, which included some crucial amino acids such as Gln172, Val173, Ser176, Lys182, His322, and Arg345. BmOR56 was edited using CRISPR/cas9 for Qiufeng, and a homozygous knockout strain QiufengM was obtained. Compared with Qiufeng, the feeding ability of QiufengM on mulberry leaf did not change significantly, but on artificial diet decreased significantly. QiufengM also showed a dependence on the concentration of mulberry leaf powder. The result indicated that other olfactory genes had a compensatory effect on the attractance of mulberry leaf after the loss of BmOR56. Transcriptome analysis of antennae showed that many genes differentially expressed between Qiufeng and QiufengM, which involved in olfactory system, glucose metabolism, protein metabolism, amino acid metabolism, and insect hormone biosynthesis. Particularly, BmIR21, BmOR53 and BmOR27 were significantly up-regulated, which may have a compensatory effect on BmOR56 loss. In addition, detoxification mechanism was activated and may cause the passivation of feeling external signals in silkworm.

A three-dimensional network structure of metal-based nanozymes for the construction of colorimetric sensors for the detection of antioxidants.

Although many excellent nanozymes have been developed, designing and synthesizing highly active nanozymes is still challenging. Here, we developed a metal-based nanozyme (metal = Co, Fe, Cu, Zn) with a three-dimensional network structure. It possesses excellent peroxidase activity and catalyzes the reaction between H2O2 and TMB to produce blue oxTMB, while antioxidants have different reducing power on the oxidation product of TMB (oxTMB), which leads to different absorbance and color changes. Using these color reactions, different nanozymes were used to form a colorimetric sensor array with seven antioxidants, and seven antioxidants were sensitively identified. And the differences between the three nanozymes were compared by density functional theory calculations and enzyme kinetic curve results. In conclusion, the colorimetric sensor array based on metal-based nanozymes provides a good strategy for the identification and detection of antioxidants, which has a broad application prospect.

Reversible switching from fluorescence to room temperature phosphorescence amplified by exciton-vibration coupling through pressure-induced tiny packing changes.

Investigating the impact of exciton-vibration coupling (EC) of molecular aggregates on regulating the excited-state dynamics and controlling room temperature phosphorescence (RTP) emissions is crucial and challenging. We designed and synthesized ArBFO molecules and cultured two crystals with similar molecular packing and completely different luminescent mechanisms from B-form fluorescence to G-form RTP. The mechanism study combining measurement of photophysical properties, time-resolved fluorescence analysis, X-ray diffraction analysis, and theoretical calculations shows that tiny changes in molecular stacking amplify the EC value from B-form to G-form H-aggregates. The larger EC value accelerates the ISC process and suppresses the radiative singlet decay. Meanwhile, the stronger intermolecular interaction restricts non-radiative transitions. All of these facilitate green RTP emission in G-form aggregates. When treated with pressure-heating cycles, the transformation between B-form and G-form aggregates leads to a reversible blue fluorescence/green RTP switch with good reproducibility and photostability. Moreover, their potential in multi-level information encryption and anti-counterfeiting application has been well demonstrated. The results of this research deepen the understanding of the effect of aggregation on the luminescence mechanism and provide a new design guidance for developing smart materials with good performance.

Split-Ring Structured All-Inorganic Perovskite Photodetector Arrays for Masterly Internet of Things.

Photodetectors with long detection distances and fast response are important media in constructing a non-contact human-machine interface for the Masterly Internet of Things (MIT). All-inorganic perovskites have excellent optoelectronic performance with high moisture and oxygen resistance, making them one of the promising candidates for high-performance photodetectors, but a simple, low-cost and reliable fabrication technology is urgently needed. Here, a dual-function laser etching method is developed to complete both the lyophilic split-ring structure and electrode patterning. This novel split-ring structure can capture the perovskite precursor droplet efficiently and achieve the uniform and compact deposition of CsPbBr3 films. Furthermore, our devices based on laterally conducting split-ring structured photodetectors possess outstanding performance, including the maximum responsivity of 1.44 × 105 mA W-1, a response time of 150 µs in 1.5 kHz and one-unit area < 4 × 10-2 mm2. Based on these split-ring photodetector arrays, we realized three-dimensional gesture detection with up to 100 mm distance detection and up to 600 mm s-1 speed detection, for low-cost, integrative, and non-contact human-machine interfaces. Finally, we applied this MIT to wearable and flexible digital gesture recognition watch panel, safe and comfortable central controller integrated on the car screen, and remote control of the robot, demonstrating the broad potential applications.

Very Early Corona Treatment-Mediated Artificial Incubation of Silkworm Eggs and Germline Transformation of Diapause Silkworm Strains.

Diapause is an important biological characteristic for many insect species to adapt to adverse environmental conditions and maintain the continuity of the race. Compared with the traditional hydrochloric acid or/and cold storage treatment methods, the artificial corona incubation technology of silkworm (Bombyx mori) eggs has many advantages including, the absence of pollution, easy operation and safety. However, this technology has not yet been applied in sericulture. In this study, we developed a novel artificial corona instrument to successfully disrupt the diapause of newly laid and refrigerated eggs from various Chinese and Japanese lineage silkworm strains. Subsequently, we invented a very early corona treatment (VECT) strategy to prevent the diapause of newly laid silkworm eggs within 4 h of oviposition. The hatching rates of the larvae were more than 95% in all diapause silkworm strains, which was comparable to the effect of the traditional HCl treatment strategy. In addition, we developed a combination strategy of VECT and pre-blastoderm microinjection and successfully created transgenic silkworms in various diapause strains. The results of the current study can aid in improving the corona artificial incubation technology and promote its application in sericulture.

phytanoyl-CoA dioxygenase domain-containing protein 1 plays an important role in egg shell formation of silkworm (Bombyx mori).

Yun7Ge is a giant egg mutant found in the silkworm variety Yun7. In comparison with the giant mutant Ge, the eggs of Yun7Ge are larger. The number of laid eggs and hatching rate of Yun7Ge are reduced, which is not conducive to reproduction. In this work, the target gene controlling giant egg trait is located on the Z chromosome and was determined through genetic analysis. Transcriptome results showed that phytanoyl-CoA dioxygenase domain-containing protein 1 (PHYHD1) on the Z chromosome was silenced, and the 25 chorion genes on chromosome 2 were remarkably downregulated. Sequence analysis showed that the 73.5 kb sequence including the PHYHD1 was replaced by a ~3.0 kb sequence. After knocking out the PHYHD1 by using CRISPR/Cas9, the chorion genes were significantly downregulated. Hence, the silencing of PHYHD1 leads to the downregulation of many chorion protein genes, thus directly causing giant eggs.

A Review of Pedal Peptide/Orcokinin-type Neuropeptides.

Neuropeptides are endogenous active substances that play important roles in a number of physiological processes and are ubiquitous in the nervous tissue in vivo. The gene encoding pedal peptide/orcokinin-type (PP/OK-type) neuropeptide is an important member of the neuropeptide gene family and is ubiquitous in invertebrates of Bilateria; orcokinin (OK) is mainly found in Arthropoda, while pedal peptide (PP) is mainly found in Mollusca. OK and PP are also present in other animals. PP/OK-type neuropeptides are a kind of multifunctional neuropeptides predominantly expressed in the nervous tissue and play important roles in the nerve regulation of movement. Moreover, OK has a number of other physiological functions. This review describes the distribution, expression, function and maturation of PP/OK-type neuropeptides to facilitate investigations of new functions and receptors of PP/OK-type neuropeptides, providing the theoretical foundation for the potential use of PP/OK-type neuropeptides in the prevention and control of agricultural and forestry pests, as an additive for skin care products and in the screening of drugs for the treatment of diabetes.

Toripalimab plus chemotherapy as second-line treatment in previously EGFR-TKI treated patients with EGFR-mutant-advanced NSCLC: a multicenter phase-II trial.

This multicenter phase-II trial aimed to investigate the efficacy, safety, and predictive biomarkers of toripalimab plus chemotherapy as second-line treatment in patients with EGFR-mutant-advanced NSCLC. Patients who failed from first-line EGFR-TKIs and did not harbor T790M mutation were enrolled. Toripalimab plus carboplatin and pemetrexed were administrated every three weeks for up to six cycles, followed by the maintenance of toripalimab and pemetrexed. The primary endpoint was objective-response rate (ORR). Integrated biomarker analysis of PD-L1 expression, tumor mutational burden (TMB), CD8 + tumor-infiltrating lymphocyte (TIL) density, whole-exome, and transcriptome sequencing on tumor biopsies were also conducted. Forty patients were enrolled with an overall ORR of 50.0% and disease-control rate (DCR) of 87.5%. The median progression free survival (PFS) and overall survival were 7.0 and 23.5 months, respectively. The most common treatment-related adverse effects were leukopenia, neutropenia, anemia, ALT/AST elevation, and nausea. Biomarker analysis showed that none of PD-L1 expression, TMB level, and CD8 + TIL density could serve as a predictive biomarker. Integrated analysis of whole-exome and transcriptome sequencing data revealed that patients with DSPP mutation had a decreased M2 macrophage infiltration and associated with longer PFS than those of wild type. Toripalimab plus chemotherapy showed a promising anti-tumor activity with acceptable safety profiles as the second-line setting in patients with EGFR-mutant NSCLC. DSPP mutation might serve as a potential biomarker for this combination. A phase-III trial to compare toripalimab versus placebo in combination with chemotherapy in this setting is ongoing (NCT03924050).

Transcriptome analysis of the eggs of the silkworm pale red egg (rep-1) mutant at 36 hours after oviposition.

The egg stage is one of the most critical periods in the life history of silkworms, during which physiological processes such as sex determination, tissue organ formation and differentiation, diapause and pigmentation occur. In addition, egg color gradually emerges around 36h after oviposition. The red egg mutant rep-1, which was recently discovered in the C1(H) wild-type, C1(H) exhibits a brown egg color. In this study, the transcriptome of the eggs was analyzed 36h after oviposition. Between the rep-1 mutant and the C1(H) wild-type, 800 differentially expressed genes (DEGs) were identified, including 325 up-regulated genes and 475 down-regulated genes. These DEGs were mainly involved in biological processes (metabolic process, cellular process, biological regulation and regulation of biological process and localization), cellular components (membrane, membrane part, cell, cell part and organelle) and molecular functions (binding, catalytic activity, transporter activity, structural molecule activity and molecular transducer activity). The pathway enrichment of these DEGs was performed based on the KEGG database, and the results indicated that these DEGs were mainly involved in pathways in the following categories: metabolic pathways, longevity-regulating pathway-multiple species, protein processing in endoplasmic reticulum, peroxisome, carbon metabolism and purine metabolism. Further analysis showed that a large number of silkworm growth- and development-related genes and ommochrome synthesis- and metabolism-related genes were differentially expressed, most of which were up-regulated in the mutant. Our research findings provide new experimental evidence for research on ommochrome pigmentation and lay the foundation for further research on the mechanism of the rep-1 mutant.

Semaphorin-1a-like gene plays an important role in the embryonic development of silkworm, Bombyx mori.

Fuyin-lethal red egg (Fuyin-lre) is a red egg mutant discovered from the germplasm resource Fuyin of Bombyx mori. The embryo of Fuyin-lre stops developing at the late stage of gastrulation due to chromosome structural variation. In this work, precise mutation sites at both ends of the mutated region were determined, and two inserted sequences with lengths of 1232 bp and 1845 bp were obtained at both ends of the mutation region. Interestingly, a bmmar1 transposon was detected in the inserted 1845 bp sequence. Bmmar1 possesses features of the Tcl/mariner superfamily of transposable elements (TEs), which belongs to class II TEs that use a DNA-mediated "cut and paste" mechanism to transpose. This finding suggests that Fuyin-lre mutation might be related to the "cut and paste" action of bmmar1. The mutation resulted in the deletion of 9 genes in the mutation region, of which the red egg gene re (BMSK0002766) did not affect embryonic development of B. mori, and the BMSK0002765 gene was unexpressed during the early stage of embryonic development. The RNA interference results of the remaining 7 genes suggest that the semaphorin-1a-like gene (BMSK0002764) had a major contribution to the embryonic lethality of Fuyin-lre.

Glucocorticoid Receptor Signaling Activates TEAD4 to Promote Breast Cancer Progression.

The Hippo pathway plays a critical role in cell growth and tumorigenesis. The activity of TEA domain transcription factor 4 (TEAD4) determines the output of Hippo signaling; however, the regulation and function of TEAD4 has not been explored extensively. Here, we identified glucocorticoids (GC) as novel activators of TEAD4. GC treatment facilitated glucocorticoid receptor (GR)-dependent nuclear accumulation and transcriptional activation of TEAD4. TEAD4 positively correlated with GR expression in human breast cancer, and high expression of TEAD4 predicted poor survival of patients with breast cancer. Mechanistically, GC activation promoted GR interaction with TEAD4, forming a complex that was recruited to the TEAD4 promoter to boost its own expression. Functionally, the activation of TEAD4 by GC promoted breast cancer stem cells maintenance, cell survival, metastasis, and chemoresistance both in vitro and in vivo. Pharmacologic inhibition of TEAD4 inhibited GC-induced breast cancer chemoresistance. In conclusion, our study reveals a novel regulation and functional role of TEAD4 in breast cancer and proposes a potential new strategy for breast cancer therapy. SIGNIFICANCE: This study provides new insight into the role of glucocorticoid signaling in breast cancer, with potential for clinical translation.

The silkworm (Bombyx mori) neuropeptide orcokinin is involved in the regulation of pigmentation.

The natural colorful cuticles of insects play important roles in many physiological processes. Pigmentation is a physiological process with a complex regulatory network whose regulatory mechanism remains unclear. Bombyx mori pigmentation mutants are ideal materials for research on pigmentation mechanisms. The purple quail-like (q-lp) and brown quail-like (q-lb) mutants originated from plain silkworm breeds 932VR and 0223JH respectively exhibit similar cuticle pigmentation to that of the quail mutant. The q-lp mutant also presents a developmental abnormality. In this study, genes controlling q-lp and q-lb mutants were located on chromosome 8 by positional cloning. Then the neuropeptide gene orcokinin (OK) was identified to be the major gene responsible for two quail-like mutants. The B. mori orcokinin gene (BommoOK) produces two transcripts, BommoOKA and BommoOKB, by alternative splicing. The CRISPR/Cas9 system and orcokinin peptides injection were used for further functional verification. We show a novel function of BommoOKA in inhibiting pigmentation, and one mature peptide of orcokinin A, OKA_type2, is the key factor in pigmentation inhibition. These results provide a reference for studying the function of orcokinin and are of theoretical importance for studying the regulatory mechanism of pigmentation.

Downregulation of aldose reductase is responsible for developmental abnormalities of the silkworm purple quail-like mutant (q-lp).

Aldose reductase (AR) is a rate-limiting enzyme in the polyol pathway and is also the key enzyme involved in diabetic complications. The silkworm purple quail-like mutant (q-lp) exhibits pigmented dots on its epidermis. The q-lp mutant also shows developmental abnormalities and decreased vitality. In this study, fat bodies from the q-lp mutant and the wildtype 932VR strain were subjected to two-dimensional gel electrophoresis (2-DE) analysis, and the Bombyx mori AR (BmAR) protein was found to be significantly downregulated in the q-lp mutant. The expression of BmAR at the mRNA level was also significantly downregulated, as verified through quantitative reverse transcription PCR (qRT-PCR). Knockdown of the expression of BmAR via RNAi resulted in a reduction of silkworm weight. The sorbitol level in q-lp was significantly lower than in the wildtype. These results suggested that the BmAR gene is closely related to the development of the q-lp mutant. Investigation of the cause of BmAR downregulation in the q-lp mutant could contribute to revealing the function of AR in insects and offers a new method of identifying AR inhibitors for the treatment of diabetic complications.

Differentially expressed genes in the head of the 2nd instar pre-molting larvae of the nm2 mutant of the silkworm, Bombyx mori.

Molting is an important physiological process in the larval stage of Bombyx mori and is controlled by various hormones and peptides. The silkworm mutant that exhibits the phenotype of non-molting in the 2nd instar (nm2) is incapable of molting in the 2nd instar and dies after seven or more days. The ecdysone titer in the nm2 mutant is lower than that in the wildtype, and the mutant can be rescued by feeding with 20E and cholesterol. The results of positional cloning indicated that structural alteration of BmCPG10 is responsible for the phenotype of the nm2 mutant. To explore the possible relationship between BmCPG10 and the ecdysone titer as well as the genes affected by BmCPG10, digital gene expression (DGE) profile analysis was conducted in the nm2 mutant, with the wildtype strain C603 serving as the control. The results revealed 1727 differentially expressed genes, among which 651 genes were upregulated and 1076 were downregulated in nm2. BLASTGO analysis showed that these differentially expressed genes were involved in various biological processes, cellular components and molecular functions. KEGG analysis indicated an enrichment of these differentially expressed genes in 240 pathways, including metabolic pathways, pancreatic secretion, protein digestion and absorption, fat digestion and absorption and glycerolipid metabolism. To verify the accuracy of the DGE results, quantitative reverse transcription PCR (qRT-PCR) was performed, focusing on key genes in several related pathways, and the results were highly consistent with the DGE results. Our findings indicated significant differences in cuticular protein genes, ecdysone biosynthesis genes and ecdysone-related nuclear receptors genes, but no significant difference in juvenile hormone and chitin biosynthesis genes was detected. Our research findings lay the foundation for further research on the formation mechanism of the nm2 mutant.

Transcriptome analysis of the epidermis of the purple quail-like (q-lp) mutant of silkworm, Bombyx mori.

A new purple quail-like (q-lp) mutant found from the plain silkworm strain 932VR has pigment dots on the epidermis similar to the pigment mutant quail (q). In addition, q-lp mutant larvae are inactive, consume little and grow slowly, with a high death rate and other developmental abnormalities. Pigmentation of the silkworm epidermis consists of melanin, ommochrome and pteridine. Silkworm development is regulated by ecdysone and juvenile hormone. In this study, we performed RNA-Seq on the epidermis of the q-lp mutant in the 4th instar during molting, with 932VR serving as the control. The results showed 515 differentially expressed genes, of which 234 were upregulated and 281 downregulated in q-lp. BLASTGO analysis indicated that the downregulated genes mainly encode protein-binding proteins, membrane components, oxidation/reduction enzymes, and proteolytic enzymes, whereas the upregulated genes largely encode cuticle structural constituents, membrane components, transport related proteins, and protein-binding proteins. Quantitative reverse transcription PCR was used to verify the accuracy of the RNA-Seq data, focusing on key genes for biosynthesis of the three pigments and chitin as well as genes encoding cuticular proteins and several related nuclear receptors, which are thought to play key roles in the q-lp mutant. We drew three conclusions based on the results: 1) melanin, ommochrome and pteridine pigments are all increased in the q-lp mutant; 2) more cuticle proteins are expressed in q-lp than in 932VR, and the number of upregulated cuticular genes is significantly greater than downregulated genes; 3) the downstream pathway regulated by ecdysone is blocked in the q-lp mutant. Our research findings lay the foundation for further research on the developmental changes responsible for the q-lp mutant.

The expression analysis of cysteine proteinase-like protein in wild-type and nm2 mutant silkworm (Lepidoptera: Bombyx mori).

The mutant of non-molting in the 2nd instar (nm2) is a recently discovered mutant of Bombyx mori. The mutant cannot molt and exuviate and died successively in premolting of 2nd instar. In this study, two dimensional gel electrophoresis (2-DE) was performed to screen the differential expression of epidermis proteins in pre-molting larvae of 2nd instar between the wild-type and nm2 mutant. Interestingly, a cysteine proteinase-like (BmCP-like) protein in nm2 was significantly higher than that of the wild-type. The transcription profiles of BmCP-like gene were investigated by quantitative real-time PCR (qRT-PCR), and the result revealed that BmCP-like mRNA was remarkably higher in nm2 than that of the wild-type. The transcription level of BmCP-like was high in the epidermis while low in the midgut and hemocytes, and fluctuate with development, while the highest in the newly molted larvae of 3rd and lowest in the pre-molting of the 1st and 2nd instar. The body of injected BmCP-like RNAi of 2nd larvae formed a dark spots around the injection place. These results suggested the BmCP-like gene play a key role in the degradation of the cuticle and epidermis layer during molting of 1st and 2nd instar silkworm. Furthermore, the ORF of BmCP-like gene in nm2 was the same to the wild-type. These studies give us a hint that BmCP-like gene maybe not the major gene responsible for nm2, but BmCP-like gene might participate in the immune systems of silkworm, and the upregulation of BmCP-like transcription in the nm2 mutant might be induced by the disadvantages that limit the growth and development of silkworm in order to survive.

Mutation of a Cuticle Protein Gene, BmCPG10, Is Responsible for Silkworm Non-Moulting in the 2nd Instar Mutant.

In the silkworm, metamorphosis and moulting are regulated by ecdysone hormone and juvenile hormone. The subject in the present study is a silkworm mutant that does not moult in the 2nd instar (nm2). Genetic analysis indicated that the nm2 mutation is controlled by a recessive gene and is homozygous lethal. Based on positional cloning, nm2 was located in a region approximately 275 kb on the 5th linkage group by eleven SSR polymorphism markers. In this specific range, according to the transcriptional expression of thirteen genes and cloning, the relative expression level of the BmCPG10 gene that encodes a cuticle protein was lower than the expression level of the wild-type gene. Moreover, this gene's structure differs from that of the wild-type gene: there is a deletion of 217 bp in its open reading frame, which resulted in a change in the protein it encoded. The BmCPG10 mRNA was detectable throughout silkworm development from the egg to the moth. This mRNA was low in the pre-moulting and moulting stages of each instar but was high in the gluttonous stage and in newly exuviated larvae. The BmCPG10 mRNA showed high expression levels in the epidermis, head and trachea, while the expression levels were low in the midgut, Malpighian tubule, prothoracic gland, haemolymph and ventral nerve cord. The ecdysone titre was determined by ELISA, and the results demonstrated that the ecdysone titre of nm2 larvae was lower than that of the wild-type larvae. The nm2 mutant could be rescued by feeding 20-hydroxyecdysone, cholesterol and 7-dehydrocholesterol (7dC), but the rescued nm2 only developed to the 4th instar and subsequently died. The moulting time of silkworms could be delayed by BmCPG10 RNAi. Thus, we speculated that the mutation of BmCPG10 was responsible for the silkworm mutant that did not moult in the 2nd instar.