Studying the role of Bombyx mori molybdenum cofactor sulfurase in Bombyx mori nucleopolyhedrovirus infection

Molybdenum cofactor sulfurase (MoCoS) is a key gene involved in the uric acid metabolic pathway that activates xanthine dehydrogenase to synthesise uric acid. Uric acid is harmful to mammals but plays crucial roles in insects, one of which is the immune responses. However, the function of Bombyx mori MoCoS in response to BmNPV remains unclear. In this study, BmMoCoS was found to be relatively highly expressed in embryonic development, gonads and the Malpighian tubules. In addition, the expression levels of BmMoCoS were significantly upregulated in three silkworm strains with different levels of resistance after virus infection, suggesting a close link between them. Furthermore, RNAi and overexpression studies showed that BmMoCoS was involved in resistance to BmNPV infection, and its antivirus effects were found to be related to the regulation of uric acid metabolism, which was uncovered by inosine- and febuxostat-coupled RNAi and overexpression. Finally, the BmMoCoS-mediated uric acid pathway was preliminarily confirmed to be a potential target to protect silkworms from BmNPV infection. Overall, this study provides new evidence for elucidating the molecular mechanism of silkworms in response to BmNPV infection and new strategies for the prevention of viral infections in sericulture.

Uridine diphosphate glucosyltransferase is vital for fenpropathrin resistance in Bombyx mori (Lepidoptera)

The silkworm (Bombyx mori) is an important model lepidopteran insect and can be used to identify pesticide resistance-related genes of great significance for biological control of pests. Uridine diphosphate glucosyltransferases (UGTs), found in all organisms, are the main secondary enzymes involved in the metabolism of heterologous substances. However, it remains uncertain if silkworm resistance to fenpropathrin involves UGT. This study observes significant variations in BmUGT expression among B. mori strains with variable fenpropathrin resistance post-feeding, indicating BmUGT's role in fenpropathrin detoxification. Knockdown of BmUGT with RNA interference and overexpression of BmUGT significantly decreased and increased BmN cell activity, respectively, indicating that BmUGT plays an important role in the resistance of silkworms to fenpropathrin. In addition, fenpropathrin residues were significantly reduced after incubation for 12 h with different concentrations of a recombinant BmUGT fusion protein. Finally, we verified the conservation of UGT to detoxify fenpropathrin in Spodoptera exigua: Its resistance to fenpropathrin decreased significantly after knocking down SeUGT. In a word, UGT plays an important role in silkworm resistance to fenpropathrin by directly degrading the compound, a function seen across other insects. The results of this study are of great significance for breeding silkworm varieties with high resistance and for biological control of pests.

Bombyx mori voltage-dependent anion-selective channel induces programmed cell death to defend against Bombyx mori nucleopolyhedrovirus infection

BACKGROUND

Voltage-dependent anion-selective channels (VDACs) serve as pore proteins within the mitochondrial membrane, aiding in the regulation of cell life and cell death. Although the occurrence of cell death is crucial for defense against virus infection, the function played by VDAC in Bombyx mori, in response to the influence of Bombyx mori nucleopolyhedrovirus (BmNPV), remains unclear.

RESULTS

BmVDAC was found to be relatively highly expressed both during embryonic development, and in the Malpighian tubule and midgut. Additionally, the expression levels of BmVDAC were found to be different among silkworm strains with varying levels of resistance to BmNPV, strongly suggesting a connection between BmVDAC and virus infection. To gain further insight into the function of BmVDAC in BmNPV, we employed RNA interference (RNAi) to silence and overexpress it by pIZT/V5-His-mCherry. The results revealed that BmVDAC is instrumental in developing the resistance of host cells to BmNPV infection in BmN cell-line cells, which was further validated as likely to be associated with initiating programmed cell death (PCD). Furthermore, we evaluated the function of BmVDAC in another insect, Spodoptera exigua. Knockdown of the BmVDAC homolog in S. exigua, SeVDAC, made the larvae more sensitive to BmNPV.

CONCLUSION

We have substantiated the pivotal role of BmVDAC in conferring resistance against BmNPV infection, primarily associated with the initiation of PCD. The findings of this study shine new light on the molecular mechanisms governing the silkworm's response to BmNPV infection, thereby supporting innovative approaches for pest biocontrol. © 2024 Society of Chemical Industry.

Advances in the extracellular signal-regulated kinase signaling pathway in silkworms, Bombyx mori (Lepidoptera)

Signaling pathways regulate the transmission of signals during organism growth and development, promoting the smooth and accurate completion of numerous physiological and biochemical reactions. The extracellular signal-regulated kinase (ERK) signaling pathway is an essential pathway involved in regulating various physiological processes, such as cell proliferation, differentiation, adhesion, migration, and more. This pathway also contributes to several important physiological processes in silkworms, including protein synthesis, reproduction, and immune defense against pathogens. Organizing related studies on the ERK signaling pathway in silkworms can provide a better understanding of its mechanism in Lepidopterans and develop a theoretical foundation for improving cocoon production and new strategies for pest biological control.

Uric acid metabolism promotes apoptosis against Bombyx mori nucleopolyhedrovirus in silkworm, Bombyx mori

The white epidermis of silkworms is due to the accumulation of uric acid crystals. Abnormal silkworm uric acid metabolism decreases uric acid production, leading to a transparent or translucent phenotype. The oily silkworm op50 is a mutant strain with a highly transparent epidermis derived from the p50 strain. It shows more susceptibility to Bombyx mori nucleopolyhedrovirus (BmNPV) infection than the wild type; however, the underlying mechanism is unknown. This study analysed the changes in 34 metabolites in p50 and op50 at different times following BmNPV infection based on comparative metabolomics. The differential metabolites were mainly clustered in six metabolic pathways. Of these, the uric acid pathway was identified as critical for resistance in silkworms, as feeding with inosine significantly enhanced larval resistance compared to other metabolites and modulated other metabolic pathways. Additionally, the increased level of resistance to BmNPV in inosine-fed silkworms was associated with the regulation of apoptosis, which is mediated by the reactive oxygen species produced during uric acid synthesis. Furthermore, feeding the industrial strain Jingsong (JS) with inosine significantly increased the level of larval resistance to BmNPV, indicating its potential application in controlling the virus in sericulture. These results lay the foundation for clarifying the resistance mechanism of silkworms to BmNPV and provide new strategies and methods for the biological control of pests.

Transcriptomic analysis of the fat body of resistant and susceptible silkworm strains, Bombyx mori (Lepidoptera), after oral treatment with fenpropathrin

The widespread use of pyrethroid pesticides has brought serious economic losses in sericulture, but there is still no viable solution. The key to solving the problem is to improve silkworm resistance to pesticides, which depends on understanding the resistance mechanism of silkworms to pesticides. This study aimed to use transcriptomes to understand the underlying mechanism of silkworm resistance to fenpropathrin, which will provide a theoretical molecular reference for breeding pesticide-resistant silkworm varieties. In this study, the fat bodies of two strains with differential resistance after 12 h of fenpropathrin feeding were analyzed using RNA-Seq. After feeding fenpropathrin, 760 differentially expressed genes (DEGs) were obtained in the p50(r) strain and 671 DEGs in the 8y strain. The DEGs involved in resistance to fenpropathrin were further identified by comparing the two strains, including 207 upregulated DEGs in p50(r) and 175 downregulated DEGs in 8y. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis showed that these fenpropathrin-related DEGs are mainly enriched in the metabolism and transporter pathways. Moreover, 28 DEGs involved in the metabolic pathway and 18 in the transporter pathway were identified. Furthermore, organic cation transporter protein 6 (BmOCT6), a transporter pathway member, was crucial in enhancing the tolerance of BmN cells to fenpropathrin. Finally, the knockdown of the expression of the homologs of BmOCT6 in Glyphodes pyloalis (G. pyloalis) significantly decreased the resistant level of larvae to fenpropathrin. The findings showed that the metabolism and transporter pathways are associated with resistance to fenpropathrin in silkworm, and OCT6 is an effective and potential target not only for silkworm breeding but also for pest biocontrol.

Fumarate mitigates disruption induced by fenpropathrin in the silkworm Bombyx mori (Lepidoptera): A metabolomics study

The silkworm Bombyx mori L. is a model organism of the order Lepidoptera. Understanding the mechanism of pesticide resistance in silkworms is valuable for Lepidopteran pest control. In this study, comparative metabolomics was used to analyze the metabolites of 2 silkworm strains with different pesticide resistance levels at 6, 12, and 24 h after feeding with fenpropathrin. Twenty-six of 27 metabolites showed significant differences after fenpropathrin treatment and were classified into 6 metabolic pathways: glycerophospholipid metabolism, sulfur metabolism, glycolysis, amino acid metabolism, the urea cycle, and the tricarboxylic acid (TCA) cycle. After analyzing the percentage changes in the metabolic pathways at the 3 time points, sulfur metabolism, glycolysis, and the TCA cycle showed significant responses to fenpropathrin. Confirmatory experiments were performed by feeding silkworms with key metabolites of the 3 pathways. The combination of iron(II) fumarate + folic acid (IF-FA) enhanced fenpropathrin resistance in silkworms 6.38 fold, indicating that the TCA cycle is the core pathway associated with resistance. Furthermore, the disruption of several energy-related metabolic pathways caused by fenpropathrin was shown to be recovered by IF-FA in vitro. Therefore, IF-FA may have a role in boosting silkworm pesticide resistance by modulating the equilibrium between the TCA cycle and its related metabolic pathways.

Bombyx mori transcription factor, E74A, beneficially affects BmNPV infection through direct interaction

BACKGROUND

Nucleopolyhedrovirus (NPV), one of the baculoviruses, is a promising biopesticide for pest control. Lepidopteran account for 70% of pests, therefore investigation on highly conserved genes associated with viral infections in the lepidopteran model, the silkworm, will serve as a valuable reference for improving the effectiveness of pest management. BmE74A is a member of the erythroblast transformation-specific (ETS) family of transcription factors in Bombyx mori, which we previously found to be highly conserved and closely associated with BmNPV. This study aimed to elucidate the role of BmE74A in viral infection.

RESULTS

A significantly high expression of BmE74A in eggs indicated its important role in embryonic development, as did relatively high expressions in the hemolymph and midgut. Significant differences in BmE74A expression in different resistant strains after BmNPV infection suggested its involvement as a response to viral infection. Moreover, RNA interference (RNAi) and overexpression experiments confirmed the important role of BmE74A in promoting viral infection. BmNPV infection was significantly suppressed and enhanced by BmE74A knockdown and overexpression, respectively. Besides, BmE74A was found to regulate the expression of BmMdm2 and Bmp53. Furthermore, the binding of ETS, the functional domain of BmE74A, to occlusion-derived virus proteins was confirmed by far-western blotting, and four viral proteins that may interact with ETS proteins were identified by mass spectrometry. Similarly, a homolog of BmE74A in Spodoptera litura was also found to be involved in larval susceptibility to BmNPV.

CONCLUSION

BmE74A promotes BmNPV proliferation by directly interacting with the virus, which may be related to the suppression of the p53 pathway. © 2022 Society of Chemical Industry.

[Clinical features and prognosis of cutaneous melanoma]

Objective: To analyze the clinical features and prognosis of patients with cutaneous melanoma. Methods: The clinical data and follow-up data of 125 patients with cutaneous malignant melanoma (CMM) treated in the Tongji Hospital of Tongji Medical College of Huazhong University of Science and Technology between February 2008 and August 2019 were collected. Kaplan-Meier method and Log rank test were used for survival analysis, and Cox proportional risk regression model was used for impact factor analysis. Results: Among the 125 patients, 12 were stage Ⅰ, 62 were stage Ⅱ, 30 were stage Ⅲ, and 21 were stage Ⅳ; 76 were acral and 49 were non-acral. The median survival time was 44 months, and the 1-, 2-, and 5-year survival rates were 85.4%, 63.2% and 38.7%, respectively. Kaplan-Meier univariate survival analysis showed that Karnofsky performance status score, tumor stage, primary site, vascular infiltration, Ki-67, BRAF, lactate dehydrogenase (LDH), and surgical treatment were related to the prognosis of patients (P<0.05). The median overall survival (OS) time of patients receiving interferon treatment was 53 months, which was better than 40 months of patients not receiving interferon treatment, but the difference was not statistically significant (P=0.448). Among stage Ⅲ patients, the median OS time of patients receiving interferon therapy was 40 months, which was better than 17 months of patients not receiving interferon therapy (P=0.012). Among stage Ⅱ patients, the 1-, 2-, and 5-year survival rates of acral patients were 97.1%, 84.7%, and 65.8%, and the 1-, 2-, and 5-year survival rates of non-acral patients were 93.3%, 70.0% and 17.0%. The prognosis of patients with stage Ⅱ acral type was better than that of non-acral type (P=0.043). The median survival time of stage Ⅲ patients with acral type was 32 months, better than 17 months of non-acral type, but the difference was not statistical significance (P=0.164). The median survival time of acral type and non-acral type was 8 months and 11 months respectively (P=0.458). Cox multivariate analysis showed that tumor stage and preoperative LDH level were independent prognostic risk factors for cutaneous melanoma. Conclusions: Interferon treatment can improve the prognosis of patients with stage Ⅲ, and stage Ⅱ acral type patients have better prognosis than that of non-acral type patients. Tumor stage and preoperative LDH level were independent prognostic risk factors for cutaneous melanoma.

Functional characterization of a low-density lipoprotein receptor in the lepidopteran model, Bombyx mori

The growth and development of metabolous insects are mainly regulated by ecdysone and juvenile hormone. As a member of the low-density lipoprotein receptor (LDLR) family, megalin (mgl) is involved in the lipoprotein transport of cholesterol which is an essential precursor for the synthesis of ecdysone. Despite extensive studies in mammals, the function of mgl is still largely unknown in insects. In this study, we characterize the function of mgl in the silkworm Bombyx mori, the model species of Lepidoptera. We find that mgl is broadly present in the genomes of lepidopteran species and evolved with divergence between lepidopterans and Drosophila. The expression pattern suggests a ubiquitous role of mgl in the growth and development in the silkworm. We further perform clustered regularly interspaced palindromic repeats (CRISPR) / CRISPR-associated protein 9-based mutagenesis of Bmmgl and find that both the development and the silk production of the silkworm are seriously affected by the disruption of Bmmgl. Our results not only explore the function of mgl in Lepidoptera but also add to our understanding of how cholesterol metabolism is involved in the development of insects.

Identification of optimal reference genes in Bombyx mori (Lepidoptera) for normalization of stress-responsive genes after challenge with pesticides

Pesticides are frequently used to control pests in agriculture due to their ease of use and effectiveness, but their use causes serious economic losses to sericulture when their production overlaps with agriculture. However, no suitable internal reference genes (RGs) have been reported in the study of silkworms in response to pesticides. In this study, a standard curve was established to detect the expression levels of seven RGs in different tissues of different silkworm strains after feeding with pesticides using reverse transcription quantitative real-time polymerase chain reaction (RT-qPCR), including BmGAPDH, BmActin3, BmTBP, BmRPL3, Bm28sRNA, Bmα-tubulin, and BmUBC, and the stability of them was evaluated by using NormFinder, geNorm, Delta CT, BestKeeper, and RefFinder. The results showed that BmGAPDH and Bmα-tubulin were relatively stable in the midgut after feeding with fenvalerate, BmGAPDH and Bmactin3 were relatively stable in the fat body, and Bmα-tubulin and Bmactin3 were relatively stable in the hemolymph, indicating that Bmactin3 was the most suitable RG when evaluating fenvalerate, followed by BmGAPDH and Bmα-tubulin. Besides, BmGAPDH and Bmactin3 were relatively stable in the midgut after treatment with DDVP, BmGAPDH and Bmα-tubulin were relatively stable in the fat body, and BmGAPDH and Bmα-tubulin were relatively stable in the hemolymph, indicating that Bmα-tubulin was the most stable RG when evaluating DDVP, followed by BmGAPDH and Bmactin3. Of note, BmGAPDH was shared by the two pesticides. The results will be valuable for RG selection in studying the pesticide response mechanism of silkworms and other lepidopteran insects.

Map-based cloning and functional analysis revealed ABCC2 is responsible for Cry1Ac toxin resistance in Bombyx mori

Bt toxins are parasporal crystals produced by Bacillus thuringiensis (Bt). They have specific killing activity against various insects and have been widely used to control agricultural pests. However, their widespread use has developed the resistance of many target insects. To maintain the sustainable use of Bt products, the resistance mechanism of insects to Bt toxins must be fully clarified. In this study, Bt-resistant and Bt-susceptible silkworm strains were used to construct genetic populations, and the genetic pattern of silkworm resistance to Cry1Ac toxin was determined. Sequence-tagged site molecular marker technology was used to finely map the resistance gene and to draw a molecular genetic linkage map, and the two closest markers were T1590 and T1581, indicating the resistance gene located in the 155 kb genetic region. After analyzing the sequence of the predicted gene in the genetic region, an ATP binding cassette transporter (ABCC2) was identified as the candidate gene. Molecular modeling and protein-protein docking result showed that a tyrosine insertion in the mutant ABCC2 might be responsible for the interaction between Cry1Ac and ABCC2. Moreover, CRISPR/Cas9-mediated genome editing technology was used to knockout ABCC2 gene. The homozygous mutant ABCC2 silkworm was resistant to Cry1Ac toxin, which indicated ABCC2 is the key gene that controls silkworm resistance to Cry1Ac toxin. The results have laid the foundation for elucidating the molecular resistance mechanism of silkworms to Cry1Ac toxin and could provide a theoretical basis for the biological control of lepidopteran pests.

[Effect of hydroxyapatite based agents on the bonding properties of universal adhesives]

Objective: To study the effect of hydroxyapatite (HA) based agents on the bonding properties of universal adhesive with different application modes, and to provide evidence for the use of adhesives after desensitization treatment. Methods: Sixty impacted third molars were extracted and selected (acquired from Department of Oral and Maxillofacial Surgery, College of Stomatology, Xi'an Jiaotong University). Four third molars were used to prepare 1 mm thick dentin disks and treated with 1% citric acid to simulate sensitive tooth models. The dentin surfaces were observed by scanning electron microscope (SEM) after treating with no desensitization (control group), desensitized by HA based toothpaste Biorepair and Dontodent Sensitive respectively (desensitizing toothpaste A group and B group), or HA paste treatment (desensitizing paste group ) (n=2 per group). The remaining teeth were selected to expose the mid-coronal dentin and establish dentin sensitivity models. Then, the specimens were divided into 4 former groups and received corresponding treatment. Each group was randomly divided into 2 subgroups, and intermediately strong universal adhesive (G-Premio Bond) was applied on the desensitized dentin by either etch-and-rinse mode or self-etch mode. Resin-dentin slice specimens (n=4 per subgroup), microtensile specimens (n=20 per subgroup) and slice specimens (n=6 per subgroup) were prepared. The microstructure and nanoleakage of the adhesive interfaces were observed by scanning electron microscopy (SEM). The microtensile strength (bond strength) and fracture mode were tested and recorded. The water permeability of the adhesive interface was observed by laser scanning confocal microscopy (LSCM). Results: SEM showed that desensitizing toothpaste and desensitizing paste could partially or entirely occlude most of the dentin tubules. For the etch-and-rinse mode, the bond strength of specimens treated with toothpaste A [(40.98±4.60) MPa], toothpaste B [(40.89±4.64) MPa] and HA paste [(41.48±3.65) MPa] was significantly higher than that of the control group [(38.58±4.28) MPa] (F=3.89,P<0.05). There was no statistically significant difference in bond strength among the 4 subgroups for self-etch modes (F=0.48,P>0.05). After desensitization, the bond strength of the control group and desensitizing groups in the self-etch mode was significantly higher than that in the etch-and-rinse mode (P<0.05). The overall fracture modes were mixed failure and interfacial failure in the control group and desensitizing groups. SEM showed speckled silver-stained particles deposited along the bottom of the hybrid layer on the bond interface of etch-and-rinse mode, and there were few silver-stained particles deposited on the bond interface of self-etch mode. LSCM showed continuous linear penetration in the hybrid layer of etch-and-rinse mode subgroups and discontinuous linear penetration in the hybrid layer of self-etch mode subgroups. Conclusions: HA based desensitizers have no adverse effect on the bond strength of intermediately strong universal adhesive and show good bonding performance accompanied with the self-etch mode.

Microbial Response to Fungal Infection in a Fungus-Growing Termite, Odontotermes formosanus (Shiraki)

The crosstalk between gut microbiota and host immunity has emerged as one of the research foci of microbiome studies in recent years. The purpose of this study was to determine how gut microbes respond to fungal infection in termites, given their reliance on gut symbionts for food intake as well as maintaining host health. Here, we used Metarhizium robertsii, an entomopathogenic fungus, to infect Odontotermes formosanus, a fungus-growing termite in the family Termitidae, and documented changes in host gut microbiota via a combination of bacterial 16S rDNA sequencing, metagenomic shotgun sequencing, and transmission electron microscopy. Our analyses found that when challenged with Metarhizium, the termite gut showed reduced microbial diversity within the first 12 h of fungal infection and then recovered and even surpassed pre-infection flora levels. These combined results shed light on the role of gut flora in maintaining homeostasis and immune homeostasis in the host, and the impact of gut flora dysbiosis on host susceptibility to infection.

CRISPR/Cas9-based knockout reveals that the clock gene timeless is indispensable for regulating circadian behavioral rhythms in Bombyx mori

Circadian rhythms, which are ubiquitous and adaptive, occur across all species, from microbes to humans, in which they organize and modify behavior and physiology. timeless (tim) is a canonical clock gene. The core composition of the Drosophila melanogaster endogenous circadian clock has been extensively investigated; however, in lepidopteran insects, including Bombyx mori, the mechanism is complicated and little is known regarding the participation of tim in the negative feedback loop responsible for behavioral activities. To arrive at a comprehensive understanding of the role of tim in the B. mori endogenous circadian clock, we exploited the clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein 9 gene editing system. We attempted to elucidate the functions of tim in the circadian clock of B. mori using Bmtim mutants. The knockouts affected two circadian behavioral activities: adult emergence and embryo hatching rhythms. Quantitative real-time polymerase chain reaction results confirmed that tim-knockouts induced relative reductions in the expression levels, and thereby the oscillation amplitudes, of Bmper and Bmclk messenger RNAs during both the photophase and scotophase. Additionally, the daily rhythmic expression of Bmdbt was upregulated in the photophase and downregulated in the scotophase in a tim-knockout. Our study reveals that tim is integral to the B. mori circadian clock and may be involved in regulating eclosion and hatching rhythms.

Bmcas-1 plays an important role in response against BmNPV infection in vitro

Apoptosis, as one kind of innate immune system, is involved in host response against pathogens innovation. Caspases play a vital role in the execution stage of host cell apoptosis. It has been reported that Bmcaspase-1 (Bmcas-1) has a close relationship with Bombyx mori nucleopolyhedrovirus (BmNPV) infection for its differentially expressed patterns after viral infection. However, its underlying response mechanism is still unclear. The significant differential expression of Bmcas-1 in different tissues of differentially resistant strains revealed its vital role in BmNPV infection. To further validate its role in BmNPV infection, budded virus (BV)-eGFP was analyzed after knockdown and overexpression of Bmcas-1 by small interfering RNA and the pIZT-mCherry vector, respectively. The reproduction of BV-eGFP obviously increased at 72 h after knockdown of Bmcas-1, and decreased after overexpression in BmN cells. Moreover, the conserved functional domain of Cas-1 among different species and the closed evolutionary relationship of Cas-1 in Lepidoptera hinted that Bmcas-1 might be associated with apoptosis, and this was also validated by the apoptosis inducer, Silvestrol, and the inhibitor, Z-DEVD-FMK. Therefore, Bmcas-1 plays an essential antiviral role by activating apoptosis, and this result lays a fundament for clarifying the molecular mechanism of silkworm in response against BmNPV infection and breeding of resistant strains.

Identification of the in vitro antiviral effect of BmNedd2-like caspase in response to Bombyx mori nucleopolyhedrovirus infection

Bombyx mori nucleopolyhedrovirus (BmNPV) is one of the most serious pathogens in sericulture, and the underlying antiviral mechanism in silkworm is still unclear. Bombyx mori Nedd2-like caspase (BmNc) has been identified as a candidate antiviral gene from previous transcriptome data, since it is differentially expressed in the midgut of differentially resistant silkworm strains following BmNPV infection. However, the molecular mechanism by which BmNc responds to BmNPV is unknown. In this study, the relationship between BmNc and BmNPV was confirmed by its significantly different expression in different tissues of differentially resistant strains after BmNPV infection. Moreover, the antiviral role of BmNc was confirmed by the significantly higher fluorescence signals of BV-eGFP after knockdown of BmNc in BmN cells, and a reduced signal after overexpression. This was further verified by the capsid gene vp39 expression, DNA copy number, and GP64 protein level in the RNAi and overexpression groups. Furthermore, the antiviral phenomenon of BmNc was found to be associated with apoptosis. In brief, BmNc showed a relatively high expression level in the metamorphosis stages, and the effect of BmNc on BmNPV infection following RNAi and overexpression was eliminated after treatment with the inducer, Silvestrol, and the inhibitor, Z-DEVD-FMK, respectively. Therefore, it is reasonable to conclude that BmNc is involved in anti-BmNPV infection via the mitochondrial apoptosis pathway. The results provide valuable information for elucidating the molecular mechanism of silkworm resistance to BmNPV infection.

The validation of the role of several genes related to Bombyx mori nucleopolyhedrovirus infection in vivo

Bombyx mori nucleopolyhedrovirus (BmNPV) is one of primary silkworm pathogens and causes a serious damage of cocoon losses every year. Recent years, many works have been done to clarify the silkworm anti-BmNPV mechanism, and a significant progress has been made in screening and studying of genes and proteins related to BmNPV infection, but several of them lacked the proofs in vivo. In this study, to further validate the function of seven newly reported genes in vivo, including BmAtlatin-n, Bmferritin-heavy chain (BmFerHCH), Bmthymosin (BmTHY), Bmseroin1, Bmseroin2, Bmnuclear hormone receptors 96 (BmNHR96), and BmE3 ubiquitin-protein ligase SINA-like 10 (BmSINAL10), the response of them in the midgut, fat body, and hemolymph of differentially resistant strains (resistant strain YeA and susceptible strain YeB) at 48 h following BmNPV infection were analyzed. The results showed that the relative stable or upregulated expression level of BmAtlatin-n, BmTHY, Bmseroin1, and Bmseroin2 in YeA resistant strain following BmNPV infection further indicated their antiviral role in vivo, compared with susceptible YeB strain. Moreover, the significant downregulation of BmFerHCH, BmNHR96, and BmSINAL10 in both strains following BmNPV infection revealed their role in benefiting virus infection, as well as the upregulation of BmFerHCH in YeB midgut and BmSINAL10 in YeB hemolymph. These data could be used to complementary the proofs of the function of these genes in response to BmNPV infection.

[Effect of histone deacetylase 2 and 4 activity on connective tissue disease associated pulmonary fibrosis in mice]

Objective: To investigate the effect of histone deacetylase (HDAC) activity on connective tissue diseases (CTD) associated pulmonary fibrosis (PF) in mice. Methods: A single tracheal administration of bleomycin induced PF in C57BL/6J male mice was performed to establish a PF model. The experimental mice were divided into three groups: bleomycin group (group B, n = 16) which was given bleomycin A2 physiological saline solution 2.5 μl/g body weight, saline group (Group C, n = 16) which was given physiological saline solution 2.5 μl/g body weight and no operation group (group N, n = 16). At 7, 14 and 21 days after administration, the animals were randomly killed and their specimens were collected. The activity of HDAC2 and HDAC4 was detected by colorimetry. Hematoxylin-eosin staining was used to evaluate pulmonary alveolitis and Masson staining for pulmonary fibrosis. The variance, correlation and binary variable correlation were analyzed. Results: The HDAC2 activity in lung tissue of mice in the bleomycin group was significantly higher than that in the no operation group (2.00±0.40 vs 1.00±0.23, P<0.05) and the saline group (2.00±0.40 vs 1.48±0.33, P<0.05). The HDAC2 activity in the bleomycin group was significantly higher than that in the no operation group (2.40±0.28 vs 1.00±0.23, P<0.01, 2.23±0.41 vs 1.00±0.23, P<0.01) and the saline group (2.40±0.28 vs 1.39±0.23, P<0.05, 2.23±0.41 vs 1.35±0.42, P<0.05). The change trend of HDAC2 activity between the bleomycin group and the saline group was different. There was no significant difference in HDAC4 activity in lung tissue of mice between the bleomycin group, the no operation group and the saline group. 14 days after tracheal administration, HDAC4 activity in the bleomycin group and the saline group were significantly higher than that in the no operation group (1.18±0.36 vs 1.00±0.12, P<0.01, 1.09±0.33 vs 1.00±0.12, P<0.01). HDAC2 activity in lung tissue of mice was positively correlated with pathological scores of alveolitis (r=0.428, P<0.01) and pulmonary fibrosis (r=0.508, P<0.01). HDAC4 activity in lung tissue of mice was positively correlated with the pathological scores of alveolitis (r=0.355, P<0.05) and pulmonary fibrosis (r=0.457, P<0.01). Binary linear regression analysis showed that HDAC2 activity had a stronger effect on the process of PF lesions than HDAC4 activity in lung tissue of mice. Conclusions: When pulmonary fibrosis occurred in mice, the activities of HDAC2 and 4 in pulmonary fibrosis were significantly increased. The activity of HDAC2 increased rapidly and lastingly, and the activity of HDAC4 fluctuated significantly and increased briefly. Changes in HDAC2 activity have stronger effects on alveolitis and fibrosis than HDAC4.

BmSd gene regulates the silkworm wing size by affecting the Hippo pathway

Insect wings are developed from the wing disc during metamorphosis. Bombyx mori, a model lepidopteran insect, loses flight ability after long-term domestication from the wild silkworm, Bombyx mandarina. The mw mutant (u11 strain) shows minute wings compared to wild type (e.g., p50 strain) wings. RNA sequencing analysis previously revealed differential Hippo-pathway-related gene expression between the u11 and p50 strains. The Hippo pathway is an evolutionarily conserved signaling cascade that controls organ size during development in animals. In this study, the function of BmSd which has been characterized as one of the Hippo-pathway-related genes was analyzed for silkworm wing development. We found that mats, warts, and hippo expression levels were higher in u11 compared to p50 wing discs. BmSd (scalloped) expression, which encodes a prominent transcriptional partner to Yorkie (Yki), gradually decreased during the wandering stage in u11, but exhibited the opposite expression pattern in p50. When BmSd was knocked down by small interfering RNA during the wandering stage in the p50 strain, 57.9% of the individuals showed minute wings. Additionally, ex, kibra, and wingless expression levels decreased in the BmSd knockdown mutant. Further, BmSd deletion mediated by clustered regularly interspaced short palindromic repeats (CRISPR) / CRISPR-associated protein 9 induced 50% of individuals with minute wings, a phenotype similar to the mw mutant. This result demonstrates that BmSd plays pivotal roles in silkworm wing development. Our results show that the Hippo signaling pathway participates and plays crucial roles in the regulation of silkworm wing development, and our findings provide a basis for further research on B. mori wing development.

Prognostic alternative splicing regulatory network of splicing events in acute myeloid leukemia patients based on SpliceSeq data from 136 cases

This study aimed to create prognostic signatures to predict AML patients' survival using alternative splicing (AS) events. The AS data, RNA sequencing data, and the survival statistics of 136 AML patients were obtained from The Cancer Genome Atlas (TCGA) and TCGA SpliceSeq databases. Total 34,984 AS events generated from 8,656 genes, 2,583 of which were survival-associated AS events, were identified using univariate Cox regression. The prognostic models constructed using independent survival-associated AS events revealed that low-risk splicing better predicted patients' survival. ROC analysis indicated that the predictive efficacy of the alternate terminator model was best in the area under the curve at 0.781. Enrichment analysis revealed several important genes (TP53, BCL2, AURKB, PPP2R1B, FOS, and BIRC5) and pathways, such as the protein processing pathway in the endoplasmic reticulum, RNA transport pathway, and HTLV-I infection pathway. The splicing network of splicing events and factors revealed interesting interactions, such as the positive correlation between HNRNPH3 and CALHM2-13010-AT, which may indicate the potential splicing regulatory mechanism. Taken together, survival-associated splicing events and the prognostic signatures for predicting survival can help provide an overview of splicing in AML patients and facilitate clinical practice. The splicing regulatory network may improve the understanding of spliceosomes in AML.

Study on the Role of Cytc in Response to BmNPV Infection in Silkworm, Bombyx mori (Lepidoptera)

Bombyx mori nucleopolyhedrovirus (BmNPV) is one of the primary pathogens of the silkworm. Cytochrome c (cytc) showed a significant response to BmNPV infection in our previous transcriptome study. However, little is known about the role of Bombyx mori cytc (Bmcytc) in resistance to BmNPV infection. In this study, the expression levels analysis of Bmcytc showed stable expression levels in selected tissues of the resistant strain AN following BmNPV infection, while there was downregulation in the susceptible strain p50, except in the malpighian tubule. To further study the role of Bmcytc in viral infection, Bmcytc was knocked down with siRNA in vitro, resulting in significant downregulation of selected downstream genes of the mitochondrial pathway, including Bmapaf, Bmcaspase-Nc, and Bmcaspase-1; this was also confirmed by overexpression of Bmcytc using the pIZT/V5-His-mCherry insect vector, except Bmcaspase-1. Moreover, knockdown of Bmcytc significantly promoted the infection process of BmNPV in vitro, while the infection was inhibited by overexpression of Bmcytc at the early stage and subsequently increased rapidly. Based on these results, we concluded that Bmcytc plays a vital role in BmNPV infection by regulating the mitochondrial apoptosis pathway. Our work provides valuable data for the clarification of the mechanism of silkworm resistance to BmNPV infection.

The regulation of crecropin-A and gloverin 2 by the silkworm Toll-like gene 18 wheeler in immune response

The innate immune system is conserved among different insect species in its response to microorganism infection. The transmembrane receptors of the Toll superfamily play an important role in activating immune response, however, the function of silkworm Toll family member 18 Wheeler (18 W) remained unclear. Here, the 18w gene in silkworm was characterized. A relatively high transcription level of Bm18w mRNA was found in Malpighian tubules, and in eggs, larvae pre-molt to fourth instar, pupae and adults. When silkworm larvae were infected with E. coli or S. aureus, Bm18w showed a significant response, especially to E. coli, but did not have antibacterial activity. To further identify the downstream antimicrobial peptide genes of Bm18w, expression of Bm18w was knocked down with siRNA in vitro, resulting in significant decreases of cecropin-A, gloverin 2, and moricin B3. The overexpression of Bm18w was carried out using pIZT/V5-His-mCherry insect vector in BmN cells and significant upregulation of cecropin-A and gloverin 2 was detected, as well as upregulation of attacin and defensin. Based on the results, we concluded that Bm18w is involved in response to bacterial infection by selectively inducing the expression of antimicrobial peptide genes, especially cecropin-A and gloverin 2. This study provides valuable data to supplement understanding of the immune pathway of the silkworm.

Knockdown of BmTCP-1β Delays BmNPV Infection in vitro

The molecular mechanism of silkworm resistance to Bombyx mori nucleopolyhedrovirus (BmNPV) infection remains unclear. The chaperonin containing t-complex polypeptide 1 (TCP-1) is essential for the folding of tubulin and actin to produce stable and functional competent protein conformation. However, little is known about this protein in silkworm. In the present study, a gene encoding the TCP-1β protein in silkworm was characterized, which has an open reading fragment of 1,611 bp encoding a predicted 536 amino acid residue-protein with a molecular weight of approximately 57.6 kDa containing a Cpn60_TCP1 functional domain. The sequence conservation is 81.52%. The highest level of BmTCP-1β mRNA expression was found in the midgut, while the lowest was in the hemolymph. To further study the function of BmTCP-1β, expression was knocked down with siRNA in vitro, resulting in significant downregulation of the selected cytoskeletal-related genes, actin and tubulin, which was also confirmed by overexpression of BmTCP-1β in BmN cells using the pIZT/V5-His-mCherry insect vector. Moreover, knockdown of BmTCP-1β significantly prolonged the infection process of BmNPV in BmN cells, which was also verified by overexpression of BmTCP-1β in BmN cells. Based on the results of the present study, we concluded that BmTCP-1β plays a vital role in BmNPV infection by regulating the expression of tubulin and actin. Taken together, our work provides valuable data for the clarification of the molecular mechanism of silkworm resistance to BmNPV infection.

A determining factor for insect feeding preference in the silkworm, Bombyx mori

Feeding preference is critical for insect adaptation and survival. However, little is known regarding the determination of insect feeding preference, and the genetic basis is poorly understood. As a model lepidopteran insect with economic importance, the domesticated silkworm, Bombyx mori, is a well-known monophagous insect that predominantly feeds on fresh mulberry leaves. This species-specific feeding preference provides an excellent model for investigation of host-plant selection of insects, although the molecular mechanism underlying this phenomenon remains unknown. Here, we describe the gene GR66, which encodes a putative bitter gustatory receptor (GR) that is responsible for the mulberry-specific feeding preference of B. mori. With the aid of a transposon-based, clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein-9 nuclease (Cas9) system, the GR66 locus was genetically mutated, and homozygous mutant silkworm strains with truncated gustatory receptor 66 (GR66) proteins were established. GR66 mutant larvae acquired new feeding activity, exhibiting the ability to feed on a number of plant species in addition to mulberry leaves, including fresh fruits and grain seeds that are not normally consumed by wild-type (WT) silkworms. Furthermore, a feeding choice assay revealed that the mutant larvae lost their specificity for mulberry. Overall, our findings provide the first genetic and phenotypic evidences that a single bitter GR is a major factor affecting the insect feeding preference.

[Clinical trial of simplified drilling method for dental implant site preparation]

Objective: To investigate the clinical effect of simplified drilling method and conventional drilling method in implants. Methods: A total of 46 patients (62 implants) were enrolled in this study that with dentition defect from May 2015 to May 2016 in the Implant department of Xi'an Jiao Tong University. The experimental group and the control group were randomly assigned according to the random number method, 23 cases in each group. The experimental group used the simplified drilling method (guided drill+ final drill), the control group using the conventional drilling method (step by step drill). The operation time, implant stability, marginal bone resorption rate and implant retention rate were compared between the two drilling methods. Results: The retention of the experiment group was 97% (31/32), the the control group was 100% (30/30). The operative time in the experiment group [(4.9±0.5) min] was significantly lower from the control group [(8.9±2.0) min] (P=0.000). There was no significant difference between the two methods in bone resorption (P=0.197), implant stability (P>0.05) and implant survival rate (P=0.492). Conclusions: The simplified drilling method can significantly reduce the operation time without compromising the clinical outcomes, and the osseointegration is well. The simplified drilling method should be used when sufficient bone mass, careful use in class II bone, forbidden in class I bone.

[Comparative analysis of the ankle joints in juvenile male soccer players with imaging]

OBJECTIVE

To investigate the characteristics of children male soccer players' ankle imaging features.

METHODS

From October 2015 to February 2016, a total of 32 male children players of two soccer clubs in Guangzhou were enrolled in this study.The ages of all cases were from 10 to 14 years, average age was (11.3±0.9) years.A total of 15 male children in region ordinary primary and secondary school students were set as control group, ages were from 10 to 14 years, average age was (12.1±1.2) years. All objects' ankle were examined by X-ray for positive and lateral positions; routine CT scanning and then on the workstation restructuring for axial, coronal and sagittal slices; and examined by MR. MR scan was with special surface coil for ankle joint for horizontal axis T2WI; coronal T1WI; coronary proton density weighted imaging (PWI); sagittal T2WI with fat suppression; sagittal PWI with isotropic and fat suppression sequence of fast field echo. The ankle bone morphological structures were observed on X-ray; the ankle bone mineral density, cortical bone thickness and sesamoid bone quantity was being observed and measured on CT; and the tenosynovitis, Achilles tendinitis, synovitis, and cancellous bone edema signal were observed on MR.

RESULTS

For study group, a total of 32 cases and 64 ankles joints were completed by X-ray, CT and MR examination.A total of 15 cases and 30 ankles joints were completed by X-ray in control group, 26 ankle joints were completed by CT scan and 22 ankle joints were completed by MR examination.X-ray examination showed there was no statistically significant difference between the two groups in ankle bone structure.CT showed that navicular bone CT value was (296±82) HU in research group and navicular bone CT value was (266±107) HU in control group, the difference was statistically significant (P=0.03). MR showed the incidence of diseases in research group that the tendon sheath peripheral inflammation was 92.2% (59/64), Achilles tendon lesions was 18.8%(12/64), edema of cancellous bone was 73.4% (47/64) , lateral malleous ligaments injuried was 43.8%(28/64), synovitis or effusion in posterior ankle was 87.5% (56/64). The incidence of diseases in control group was that tendon sheath peripheral inflammation was 31.8%(7/22), Achilles tendon lesions was 0/22, edema of cancellous bone was 0/22, lateral malleous ligaments injuried was 0/22, synovitis or effusion in posterior ankle was 54.5% (12/22). There was statistically significant difference between these two groups (all P<0.05).

CONCLUSION

Compared with the control group, children's male soccer players ankle bone structure, bone cortex thickness and bone mineral density there were no obvious difference. In the tenosynovitis, Achilles tendinitis, synovitis, bone marrow edema, lateral malleous ligaments injuried were significantly higher than the control group.

[Efficacy of thrombolytic therapy using reteplase in cases with acute ST-segment elevation myocardial infarction: results from a multicenter clinical trial]

Objective: To evaluate the efficacy and safety of intravenous thrombolytic therapy using reteplase in patients with acute ST-segment elevation myocardial infarction (STEMI). Method: A total of 73 hospitals from Henan province took part in this clinical trials during October 2012 to October 2014, 1 226 cases (1 014 male (82.7%), mean age 59.0 (51.0, 66.0) years) with acute STEMI received reteplase as thrombolytic agent.Reperfusion rate was judged according to the clinical symptoms, electrocardiogram, myocardial enzymes and heart rhythm, and the rate of cardiovascular events and bleeding events during hospitalization was also observed.Bleeding events were evaluated with global utilization of streptokinase and tissues plasminogen activator for occluded coronary arteries (GUSTO) criteria.Subgroup analysis was performed to compare the effects of various thrombolysis timing (time from onset to thrombolysis≤6 h or 6-12 h) on reperfusion rate, cardiovascular events and bleeding events rate. Results: The reperfusion rate was 89.3% (1 089/1 219) at 120 minutes after the thrombolysis, average recanalization time was (59.96±26.86) minutes.The reperfusion rate of ≤6 h thrombolysis group was significantly higher than in 6-12 hours group (90.3% (988/1094) vs. 80.8% (101/125), P=0.001), while in-hospital mortality (2.6%(28/1 094) and 0.8% (1/125), P=0.352) and rate of bleeding (5.9%(64/1 094) and 5.6%(7/125), P=0.910) were similar between the two groups. The total in-hospital mortality after thrombolysis was 2.4% (29/1219), which was significantly higher in failed recanalization group than in recanalization group (10.8%(14/130) vs. 1.4%(15/1089), P< 0.001). The total rate of bleeding after thrombolysis was 5.8% (71/1219), there were 3 severe bleeding cases according to GUSTO classification (0.2%), all of them were cerebral hemorrhage, and 2 out of 3 cases died. Conclusions: Reteplase use is related to high recanalization rate and low cardiovascular events and bleeding rate and our results thus show that reteplase is a safe and effective thrombolytic agent for STEMI patients.

[Rosenmüller valve during endoscopic dacryocystorhinostomy in treating refractory nasolacrimal duct obstruction]

OBJECTIVE

The objective of this study was to assess the efficacy of exposing Rosenmüller valve during endonasal endoscopic dacryocystorhinostomy (EES-DCR) in treating refractory nasolacrimal duct obstruction.

METHODS

Thirty six patients (47 eyes) with refractory nasolacrimal duct obstruction were entered into this study, including 13 patients (15 eyes) underwent nasal lacrimal duct intubation before, 18 patients (26 eyes) with small lacrimal sac, 2 patients underwent DCR before, 1 patient with functional nasal lacrimal duct obstruction, 1 patient with lacrimal mucocele, 1 patient with nasal trauma. During the DCR, the bone window was enlarged as wide as possible and the valve of Rosenmüller was exposed. The intubation of the lacrimal apparatus was performed if the lacrimal sac was very small and the Rosenmüller valve was tight. Functional endoscopic sinus surgery and septoplasty were performed simultaneously if necessary. Postoperatively, each patient was assessed by the symptom and nasal endoscopy.

RESULTS

The postoperative follow-up period ranged from 3 to 36 months. Thirty two patients(89.4%, 42/47 eyes) were cured, which presented as the disappearance of symptoms, the patency of the lacrimal ostium and the lacrimal duct irrigation was clear. One patient (2.1%, 1/47 eyes) was improved, which presented as the improvement of symptoms, a few hypertrophic scar around the lacrimal ostium and the lacrimal duct irrigation was clear. Four cases failed (8.5%, 4/47), which presented as symptomatic and obstruction of the lacrimal ostium. The total effective rate reached to 91.5%. No serious postoperative complications were found in all cases.

CONCLUSIONS

To expose Rosenmüller valve during endoscopic DCR in treating patients with refractory nasolacrimal duct obstruction could obviously increase the operative success rate, fewer complications, with no facial surgical scar. It is an ideal way to treat the refractory nasolacrimal duct obstruction.

Pioglitazone up-regulates long non-coding RNA MEG3 to protect endothelial progenitor cells via increasing HDAC7 expression in metabolic syndrome

Long non-coding RNA (lncRNA) maternally expressed 3 (MEG3) is expressed in endothelial cells and involved in angiogenesis and vascular function. It was proposed that MEG3 participates in the process of endothelial progenitor cells (EPCs) functions in metabolic syndrome (MetS). In this study, the circulating EPCs number and function were decreased in MetS subjects. The MEG3 expression was expressed at a lower level and microRNA-140-5p (miR-140-5p) was expressed at a higher level in circulating EPCs of subjects with MetS. Pioglitazone reversed the alterations of EPCs function and the expression levels of MEG3 and miR-140-5p in EPCs. In bone marrow-derived EPCs exposed to palmitate, down-regulation of miR-140-5p canceled the increase of MEG3 expression level induced by Pioglitazone. Overexpression of MEG3 resulted in the down-regulation of miR-140-5p. The luciferase reporter assay and RIP assay showed that MEG3 targeted miR-140-5p. In addition, the HDAC7 expression levels were regulated by miR-140-5p and MEG3. These findings demonstrated that Pioglitazone up-regulated MEG3 expression to protect EPCs via decreasing miR-140-5p expression and increasing HDAC7 expression in MetS, which may be a novel therapeutic target for preventing and treating MetS.

Marker-assisted selection in breeding silkworm strains with high tolerance to fluoride, scaleless wings, and high silk production

In the silkworm (Bombyx mori), tolerance to fluoride and scaleless wings are controlled by the dominant gene Dtf (dominant tolerance to fluoride) and recessive gene nlw (no Lepidoptera wings), respectively, and these genes have been mapped by using simple sequence repeat and sequence tag site markers. Marker-assisted evaluation and selection of silkworms with fluoride tolerance and scaleless wings were used for predicting fluoride resistance and scaleless wings in backcrossed animals. A silkworm strain was bred using this method, and its economic characteristics were found to be similar to those of commercial silkworms. These methods will therefore be useful for silkworm breeding programs and in screening for two or more characteristics of interest for segregating populations.

Toll-like receptor 3 polymorphism is not associated with neovascular age-related macular degeneration and polypoidal choroidal vasculopathy in the Chinese

Toll-like receptor 3 (TLR3) variants in mainland northern Chinese patients with polypoidal choroidal vasculopathy (PCV) and neovascular age-related macular degeneration (nAMD) were investigated. The complete genes of TLR3, including all exons and the promoter region, were assessed using direct sequencing technology of 284 unrelated mainland northern Chinese individuals: 96 nAMD patients, 92 PCV patients, and 96 controls. Six single nucleotide polymorphisms were identified: rs5743303, rs5743305, rs5743312, rs3775291, rs3775290, and rs6830345. The distribution of TLR3 genotypes for nAMD and PCV was not significantly different compared with normal controls. This study indicates that the TLR3 gene polymorphism is not associated with nAMD and PCV in northern Chinese patients.

Marker-assisted selection in breeding silkworm strains with high silk production and resistance to the densonucleosis virus

In the silkworm (Bombyx mori), resistance to the Zhenjiang (China) strain of the densonucleosis virus (DNV-Z) is controlled by the recessive gene nsd-Z (non-susceptible to DNV-Z), which is linked to 7 simple-sequence repeat markers. Marker-assisted evaluation and selection of DNV-Z-resistant silkworms were used for predicting DNV-resistance in backcrossed animals. A silkworm race was bred using this method, and its economic characteristics were found to be similar to those of commercial silkworm races. These markers will therefore be useful for silkworm breeding programs and in screening for densonucleosis resistance in segregating populations.

[Molecular mapping of test mapping strain for 18th linkage group recessive genes elp, ch-2 and mln in silkworm (Bombyx mori)]

The ellipsoid egg, the second recessive gene of chocolate larvae, and melanism are controlled by three recessive genes, elp, ch-2, and mln in silkworm, respectively. Their order and genetic distance have been scheduled in established linkage group. Owing to lack of crossing over in females, the reciprocal backcrossed F1(BC1) progenies were bred for linkage analysis using the wild type silkworm strain P50(+elp+ch-2+mln /+elp+ch-2+mln) and W18 with ellipsoid egg, the second recessive gene of chocolate larvae, and melanism (elp ch-2 mln / elp ch-2 mln). In this research, we mapped three mutant genes, elp, ch-2, and mln on the chromosome 18 based on the SSR linkage map and STS markers designed based on silkworm genome sequence. The established linkage group, molecular linkage group, and the physic map of chromosome 18 had been corresponded. The genetic distance for this chromosome in this research was 94.2 cM, and the order of the mutants and molecular markers were consistent with the established silkworm linkage maps and the fine genome sequences. This research will lay important bases for map-based cloning for other mutants on chromosome 18.

Influence of RNAi knockdown for E-complex genes on the silkworm proleg development

Larvae of many holometabolous insects possess abdominal appendages called prolegs. Lepidoptera larvae have prolegs in the segments A3-A6. Functions of Lepidoptera hox genes on these abdominal appendages development is still a controversial issue. In this article, we report the use of double strand RNA (dsRNA)-mediated interference (RNAi) to dissect the function of some hox genes, specifically E-complex genes Ubx, abd-A, and Abd-B, in the ventral appendage development of the Lepidoptera silkworm, Bombyx mori. We found that Ubx RNAi caused leg identity in A1 segment, abd-A RNAi caused severe defect of abdominal prolegs and Abd-B RNAi allowed proleg identity in more posterior abdominal segments. These results confirm that Lepidoptera hox genes Ubx and Abd-B have evolved the repressing function to ventral appendage development, which is similar to those of Drosophila. However, Lepidoptera abd-A might have been modified distinctively during evolution, and has important roles in directing the development of prolegs.

Effect of ICSI on gene expression and development of mouse preimplantation embryos

BACKGROUND

In vitro culture (IVC) and IVF of preimplantation mouse embryos are associated with changes in gene expression. It is however not known whether ICSI has additional effects on the transcriptome of mouse blastocysts.

METHODS

We compared gene expression and development of mouse blastocysts produced by ICSI and cultured in Whitten's medium (ICSI(WM)) or KSOM medium with amino acids (ICSI(KSOMaa)) with control blastocysts flushed out of the uterus on post coital Day 3.5 (in vivo). In addition, we compared gene expression in embryos generated by IVF or ICSI using WM. Global pattern of gene expression was assessed using the Affymetrix 430 2.0 chip.

RESULTS

Blastocysts from ICSI fertilization have a reduction in the number of trophoblastic and inner cell mass cells compared with embryos generated in vivo. Approximately 1000 genes are differentially expressed between ICSI blastocyst and in vivo blastocysts; proliferation, apoptosis and morphogenetic pathways are the most common pathways altered after IVC. Unexpectedly, expression of only 41 genes was significantly different between embryo cultured in suboptimal conditions (WM) or optimal conditions (KSOM(aa)).

CONCLUSIONS

Our results suggest that fertilization by ICSI may play a more important role in shaping the transcriptome of the developing mouse embryo than the culture media used.

[Mapping of non-lepis wing gene nlw in silkworm (Bombyx mori) using SSR and STS markers]

The non-lepis wing of silkworm (Bombyx mori) is controlled by the recessive gene, nlw. Owning to lack of crossing over in females, the reciprocal backcrossed F(1) (BC(1)) progenies were used for linkage analysis and mapping of nlw based on the SSR linkage map and STS markers using the wild type (+(nlw)/+(nlw)) silkworm strain P50 and U06 with scaleless wing (nlw/nlw). The nlw gene was linked to eight SSR markers and one STS marker. All the individuals with the wild type in the BC1F (Using F(1) as female to backcross to the recessive parent, that is (U06xP50)xU06) showed heterozygous profile of (U06xP50) F(1), and the ones with non-lepis wing in BC1F exhibited the homozygous profile of the strain U06. Using a reciprocal BC1M (Using F1 as male to backcross to the recessive parent, that is U06x(U06xP50))cross, we constructed a linkage map of 125.6 cM, and the distance between nlw and the nearest marker cash2p was 11.4 cM.

Differentially expressed genes in resistant and susceptible Bombyx mori strains infected with a densonucleosis virus

We investigated variations in the gene expression of Bombyx mori following infection with a densonucleosis virus (BmDNV-Z). Two B. mori near-isogenic lines, Jingsong and Jingsong.nsd-Z.NIL, which are highly susceptible and completely resistant to BmDNV-Z, respectively, were used in this study. The infection profiles of BmDNV-Z in the midguts of the B. mori Jingsong and Jingsong.nsd-Z.NIL larvae revealed that the virus invaded the midguts of both of these strains. However, its proliferation was notably inhibited in the midgut of the resistant strain. By using the suppression subtractive hybridization method, three cDNA libraries were constructed to compare BmDNV-Z responsive gene expression between the two silkworm lines. In total, 151 differentially expressed genes were obtained. Real-time qPCR analysis confirmed that 11 genes were significantly up-regulated in the midgut of the Jingsong.nsd-Z.NIL strain following BmDNV-Z infection. Our results imply that these up-regulated genes might be involved in B. mori immune responses against BmDNV infection.

Differences of YMDD mutational patterns, precore/core promoter mutations, serum HBV DNA levels in lamivudine-resistant hepatitis B genotypes B and C

The aims of this study were to investigate the viral differences among lamivudine-resistant hepatitis B virus (HBV) genotypes B and C in vivo. Fifty-three patients carrying lamivudine-resistant HBV were enrolled in this study. HBV genotypes, Levels of alanine aminotransferase (ALT), HBV DNA levels were monitored during therapy. The polymerase and precore/core promoter genes were amplified by polymerase chain reaction and their products were sequenced directly. Among 53 patients resistant HBV genotypes B and C accounted for 41.50% and 58.50%, respectively. The occurrence of reverse transcriptase rt204I mutants was lower in genotype B (36.36%) than that in genotype C (87.10%), whereas rt204V mutants was higher in genotype B (63.64%) than that in genotype C (12.90%). The occurrence of precore mutation (nt1896A) was higher in genotype B (77.27%) than that in genotype C (32.26%). Serum HBV DNA levels after emergence of lamivudine resistance were higher in genotype C (7.71 +/- 0.80 Log copies/mL) compared with genotype B (6.97 +/- 0.77 Log copies/mL). Multivariate analysis identified pretreatment HBV DNA levels, HBeAg status and HBV genotype as independent factors associated with a shorter time to lamivudine resistance(P = 0.035, P = 0.006 and P = 0.001, respectively). Multivariate analysis showed that HBV genotype (P = 0.004) and pretreatment ALT levels (P = 0.01) was independently associated with YMDD mutational patterns. The results showed that the YMDD mutational patterns, precore mutation and serum HBV DNA levels differ between lamivudine-resistant HBV genotypes B and C in vivo. It is valuable for treatment of lamivudine-resistant HBV in clinic.

PCR tools for the verification of the specific identity of ascaridoid nematodes from dogs and cats

Based on the sequences of the internal transcribed spacers (ITS-1 and ITS-2) of nuclear ribosomal DNA (rDNA) of Toxocara canis, Toxocara cati, Toxocara malaysiensis and Toxascaris leonina, specific forward primers were designed in the ITS-1 or ITS-2 for each of the four ascaridoid species of dogs and cats. These primers were used individually together with a conserved primer in the large subunit of rDNA to amplify partial ITS-1 and/or ITS-2 of rDNA from 107 DNA samples from ascaridoids from dogs and cats in China, Australia, Malaysia, England and the Netherlands. This approach allowed their specific identification, with no amplicons being amplified from heterogeneous DNA samples, and sequencing confirmed the identity of the sequences amplified. The minimum amounts of DNA detectable using the PCR assays were 0.13-0.54ng. These PCR assays should provide useful tools for the diagnosis and molecular epidemiological investigations of toxocariasis in humans and animals.

Simple sequence repeat-based consensus linkage map of Bombyx mori

We established a genetic linkage map employing 518 simple sequence repeat (SSR, or microsatellite) markers for Bombyx mori (silkworm), the economically and culturally important lepidopteran insect, as part of an international genomics program. A survey of six representative silkworm strains using 2,500 (CA)n- and (CT)n-based SSR markers revealed 17-24% polymorphism, indicating a high degree of homozygosity resulting from a long history of inbreeding. Twenty-nine SSR linkage groups were established in well characterized Dazao and C108 strains based on genotyping of 189 backcross progeny derived from an F(1) male mated with a C108 female. The clustering was further focused to 28 groups by genotyping 22 backcross progeny derived from an F(1) female mated with a C108 male. This set of SSR linkage groups was further assigned to the 28 chromosomes (established linkage groups) of silkworm aided by visible mutations and cleaved amplified polymorphic sequence markers developed from previously mapped genes, cDNA sequences, and cloned random amplified polymorphic DNAs. By integrating a visible mutation p (plain, larval marking) and 29 well conserved genes of insects onto this SSR-based linkage map, a second generation consensus silkworm genetic map with a range of 7-40 markers per linkage group and a total map length of approximately 3431.9 cM was constructed and its high efficiency for genotyping and potential application for synteny studies of Lepidoptera and other insects was demonstrated.

[The acquisition of two silkworm CAPs markers and their use in genetic diversity and phylogenetic relationship]

Cleaved amplified polymorphic sequence (CAPs) markers are based on PCR amplification of known genes, cDNA sequences or RAPD sequences. The PCR products are digested by restriction enzymes, generating the simple type of data as heterozygotes and homozygotes. Here we designed primers based on silkworm attacin and alpha-amylase genes, then digested the PCR products in silkworm strains P50, C108 and their progeny F1 using 4 different restriction enzymes respectively. Furthermore, the genetic diversity and phylogenetic relationship of 12 silkworm strains were investigated using the obtained two CAPs markers.

Identification of a hyaluronic acid (HA) binding domain in the PH-20 protein that may function in cell signaling

The macaque sperm surface protein PH-20 is a hyaluronidase, but it also interacts with hyaluronic acid (HA) to increase internal calcium ( [Ca(2+)](i) ) in the sperm cell. A region of the PH-20 molecule, termed Peptide 2 (aa 205-235), has amino acid charge homology with other HA binding proteins. The Peptide 2 sequence was synthesized and two recombinant PH-20 proteins were developed, one containing the Peptide 2 region (G3, aa 143-510) and one without it (E12, aa 291-510). On Western blots, affinity-purified anti-Peptide 2 IgG recognized the 64 kDa band corresponding to PH-20 in acrosome intact sperm and, under reducing conditions, recognized the whole 67 kDa PH-20 and the endoproteolyzed N-terminal fragment of PH-20. HA conjugated to a photoaffinity substrate specifically bound to sperm surface PH-20. Indirect immunofluorescence demonstrated that Fab fragments of anti-Peptide 2 IgG bound to the head of live sperm. Biotinylated HA was bound by Peptide 2 and by sperm extracts in a microplate binding assay, and this binding was inhibited by Fab fragments of anti-Peptide 2 IgG. Biotinylated HA bound to the G3 protein and this binding was inhibited by anti-Peptide 2 Fab, but HA did not bind to the E12 protein. Fab fragments of anti-Peptide 2 IgG inhibited the increase in [Ca(2+)](i) induced in macaque sperm by HA. Our results suggest that the Peptide 2 region of PH-20 is involved in binding HA, which results in the cell signaling events related to the elevation of [Ca(2+)](i) during sperm penetration of the cumulus.

Characterization of the active site of monkey sperm hyaluronidase

The mammalian sperm hyaluronidase, PH-20, is active in macaque spermatozoa at neutral and acid pH. Antibodies were produced to synthesized peptides representing regions of PH-20 that may be involved in hyaluronidase activity and designated peptide 1 (amino acid sequence 142-172) and peptide 3 (amino acid sequence 277-297). Western blotting of proteins extracted from the surface of acrosome-intact spermatozoa showed that the two peptide-specific, affinity-purified IgGs label a 64 kDa band corresponding to the PH-20 molecule. Western blots of acrosome-reacted spermatozoa showed that, under reducing conditions, the two anti-peptide IgGs label the 44 kDa band only, which represents the N-terminal fragment of PH-20. Anti-peptide 3 IgG also labels the 53 kDa form of PH-20 in extracts of acrosome-reacted spermatozoa. Peptide-specific, affinity-purified Fab fragments from both IgGs were shown by fluorescence microscopy and transmission electron microscopy to label the sperm plasma membrane, fused acrosomal vesicles, acrosomal matrix and inner acrosomal membrane. Fab fragments of anti-peptide 1 IgG, but not anti-peptide 3 IgG, inhibited hyaluronidase activity of PH-20 from the sperm surface and from extracts of acrosome-reacted spermatozoa at pH 7.0. Fab fragments of both anti-peptide IgGs inhibited sperm hyaluronidase activity at pH 5.0. It is concluded that the region of PH-20 encompassed by the amino acid sequence 142-172 is essential for hyaluronidase activity at neutral pH, whereas the region of amino acid sequence 277-297 may be more important at a lower pH. It is likely that these two regions are the acid/base catalyst site and the nucleophilic site, respectively, of PH-20 hyaluronidases.

Click evoked EMG responses in sternocleidomastoid muscles: characteristics in normal subjects

Recordings were obtained from a total of 25 normal subjects of the electromyographic (EMG) responses in the sternocleidomastoid muscle (SCM) to intense sound stimuli. While previous authors have demonstrated these responses exist, it has remained unclear whether the EMG response is unilateral or bilateral in nature. Accordingly, we chose a remote site, linked-wrists, for our reference electrodes so that we could be certain that no significant volume conduction of potentials could occur from the source in the SCM to the reference site. When this was done we found that if the sternum was used as a reference site, as was the case in previous studies, some subjects exhibited bilateral responses while in others, the response was ipsilateral. However, with linked-wrists as the reference site, responses were always purely ipsilateral. Furthermore, recordings that used the sternum or the ipsilateral mastoid process as active sites and linked-wrists as a reference, exhibited responses which were inverted. Thus, both the sternum and the ipsilateral mastoid process are electrically active due to volume conduction from the nearby source in the SCM. The ambiguity in previous recordings can be attributed to the use of these active sites as a reference. When SCM responses are recorded versus a remote, electrically inactive site, the responses are purely ipsilateral.

Hyaluronic acid and the cumulus extracellular matrix induce increases in intracellular calcium in macaque sperm via the plasma membrane protein PH-20

The hyaluronic acid (HA)-rich extracellular matrix (ECM) of the cumulus oophorus is known to facilitate fertilization. It has been suggested that HA may enhance fertilisation in a number of species, and in macaque sperm, HA has been shown to increase the number of acrosome reactions that follow sperm binding to the zona pellucida. In this study, we investigated the effects of HA on intracellular Ca2+ in capacitated cynomolgus macaque sperm. Fluorometry studies using the intracellular Ca2+ indicator Fluo-3 showed that addition of 100 micrograms/ml of HA induced a rapid increase in intracellular Ca2+. This Ca2+ increase (approximately 2-3 times above basal levels) was inhibited by preincubation of sperm with Fab fragments of anti-recombinant PH-20 IgG. The frequency of acrosome reactions in sperm exposed to HA was not above control levels. A synthetic gel was prepared with similar viscosity to the cumulus and with HA trapped in its matrix. Video imaging of individual sperm was used to demonstrate that capacitated sperm swimming into the HA gel had increased intracellular Ca2+ levels. Preincubation of sperm with Fab fragments of anti-PH-20 IgG inhibited the increased intracellular Ca2+ levels induced by the HA gel. Sperm in control gel (no HA) did not show increased intracellular Ca2+, while sperm in gel containing anti-PH-20 IgG showed increased Ca2+ (positive control). Sperm loaded with Fluo-3 were allowed to interact with cynomolgus macaque cumulus masses, and sperm within the cumulus ECM clearly showed increased intracellular Ca2+ that was inhibited when sperm were preincubated in anti-PH-20 Fab. Fluorescein isothiocyanate (FITC)-HA was found to bind to sperm over the acrosomal region, corresponding to PH-20 localisation, and this binding could be inhibited by preincubation of sperm with anti-PH-20 fragments. The results of this study show that HA increases intracellular Ca2+ in macaque sperm through interaction with plasma membrane PH-20. We propose that HA binding to plasma membrane PH-20 induces an aggregation of receptors that in turn results in intracellular signalling. As a result, sperm have higher basal CA2+ levels and are more responsive to induction of the acrosome reaction after binding to the zona pellucida.

Autosome search for schizophrenia susceptibility genes in multiply affected families

We have analysed 298 polymorphic markers in 13 families multiply affected with schizophrenia and related disorders using a combination of radiolabelled and fluorescent-based methodologies. The markers were distributed throughout the autosomes at an average spacing of 12.8 cM. The data were analysed with two-point linkage analysis (MLINK) and heterogeneity testing (HOMOG). Several genetic models were used ranging from near dominant to fully recessive. Multi-point analysis was performed for 27 regions demonstrating either contiguously positive lod scores in two or more consecutive markers, and in regions with two-point lod score(s) of 1.0 or above in a single marker. A proportion of the multi-point regions have been implicated in previous studies, thereby decreasing risk of false-positive results. However neither our two-point, nor multi-point scores reached the threshold value for significance of 3. 6. Nevertheless three regions were suggestive of linkage.

PH-20 but not acrosin is involved in sperm penetration of the macaque zona pellucida

In this study, we investigated the functions of PH-20 and acrosin during the interaction of macaque sperm with the zona pellucida. Both of these sperm enzymes have been reported to be present on the inner acrosomal membrane of acrosome reacted sperm, and have been suggested to play a role during secondary sperm-zona binding in other species. Anti-macaque PH-20 IgG, anti-pig acrosin IgG and soybean trypsin inhibitor (SBTI) were used as probes for immunolocalization of the two proteins at the ultrastructural level, and as reagents for blocking sperm penetration of the macaque zona pellucida in vitro. As a control, we performed similar studies with antibodies to CD-46, which is also located on the inner acrosomal membrane, but has no known function in sperm-zona pellucida interaction. After labeling with anti-acrosin IgG, gold label was not present on the sperm surface before the acrosome reaction, but was detected over the entire head of sperm that were induced to acrosome react with calcium ionophore A23187. In contrast, when sperm were induced to acrosome react by binding to intact zona pellucida, acrosin was present in the acrosomal shroud but not on the inner acrosomal membrane. Similar results were obtained when SBTI was used as a probe for enzyme localization. PH-20 and CD-46 were demonstrated on the inner acrosomal membrane of sperm induced to acrosome react by ionophore treatment and by zona binding. Neither anti-acrosin IgG nor anti-CD-46 IgG affected sperm penetration of the zona at concentrations up to 300 microg/ml, but zona penetration was blocked completely when anti-PH-20 IgG (100 microg/ml) was present during sperm-oocyte interaction. Ultrastructural observations of oocytes incubated with anti-PH-20 IgG showed that acrosomal shrouds were present on the zona surface but no sperm had begun to penetrate into the zona substance. We conclude that anti-PH-20 IgG prevented sperm penetration of the macaque zona pellucida by interference with secondary sperm-zona binding, rather than primary sperm-zona binding or the zona-induced acrosome reaction. Acrosin was not detected on the inner acrosomal membrane of sperm that are induced to acrosome react after zona binding, and acrosin does not appear to be critical for sperm penetration of the macaque zona pellucida.

Biochemical characterization of the PH-20 protein on the plasma membrane and inner acrosomal membrane of cynomolgus macaque spermatozoa

Preparations of sperm membranes (plasma membranes and outer acrosomal membranes) and denuded sperm heads were isolated from macaque sperm, and the PH-20 proteins present were characterized by Western blotting, hyaluronic acid substrate gel analysis, and a microplate assay for hyaluronidase activity. Because we have shown previously that PH-20 is located on the plasma membrane and not on the outer acrosomal membrane, the PH-20 in the membrane preparations was presumed to be plasma membrane PH-20 (PM-PH-20). PM-PH-20 had an apparent molecular weight of 64 kDa and the optimum pH for its hyaluronidase activity was 6.5. The PH-20 associated with denuded sperm heads was localized by immunogold label to the persistent inner acrosomal membrane (IAM) and was presumed to be IAM-PH-20, which included a major 64 kDa form and a minor 53 kDa form. The 53 kDa form was not detected in extracts of denuded sperm heads from acrosome intact sperm that were boiled in nonreducing sample buffer, but was present in extracts of sperm heads from acrosome reacted sperm and in the soluble material released during the acrosome reaction, whether or not the samples were boiled. Substrate gel analysis showed that the hyaluronidase activity of the 53 kDa form of PH-20 was greatest at acid pH, and this activity was probably responsible for the broader and lower optimum pH of IAM hyaluronidase activity. When hypotonic treatment was used to disrupt the sperm acrosome and release the acrosomal contents, less than 0.05% of the total hyaluronidase activity was released. The PH-20 protein released by hypotonic treatment was the 64 kDa form and not the 53 kDa form, suggesting that its source might be the disrupted plasma membranes. Our experiments suggest that the soluble form of hyaluronidase, which is released at the time of the acrosome reaction, is derived from the IAM. This soluble hyaluronidase is composed of both the 64 kDa form and 53 kDa form of PH-20. The 53 kDa form appears to be processed from the 64 kDa form at the time of the acrosome reaction.