Overexpression of Ultrabithorax Changes the Development of Silk Gland and the Expression of Fibroin Genes in Bombyx mori.

Ultrabithorax (Ubx) is a member of the Hox gene group involved in cell fate decisions, cell proliferation and organ identity. Its function has been extensively researched in Drosophila melanogaster but little is known about it in Lepidoptera. To uncover the function of Ubx in the development of lepidopterans, we constructed the Ubx overexpression (UbxOE) strain based on the Nistari strain of Bombyx mori. The UbxOE strain showed a small body size, transparent intersegmental membrane and abnormal posterior silk gland (PSG). In the current study, we focused on the effect of Ubx overexpression on the posterior silk gland. As the major protein product of PSG, the mRNA expression of fibroin heavy chain (Fib-H) and fibroin light chain (Fib-L) was upregulated three times in UbxOE, but the protein expression of Fib-H and Fib-L was not significantly different. We speculated that the overexpression of Ubx downregulated the expression of Myc and further caused abnormal synthesis of the spliceosome and ribosome. Abnormalities of the spliceosome and ribosome affected the synthesis of protein in the PSG and changed its morphology.

Bmo-miR-2780a regulates the expression of the sericin-1 gene of Bombyx mori.

Silk production in Bombyx mori L. is largely determined by the expression of genes encoding fibroin and sericin. Here, we examined the regulatory function of a microRNA (miRNA) on silk gene expression using the sericin-1 gene (BmSer-1). First, we downloaded whole mature miRNAs of silkworm from miRBase and identified bmo-miR-2780a as a candidate miRNA for the regulation of BmSer-1 expression. We used semi-quantitative reverse transcription polymerase chain reaction (RT-PCR) with stem-loop primers to investigate the expression profile of bmo-miR-2780a and its predicted target gene BmSer-1 in seven different tissues from 5th instar day-3 larvae, including head, fat body, anterior silk gland (ASG), middle silk gland (MSG), posterior silk gland (PSG), middle gut, and hemolymph. Our results showed that bmo-miR-2780a was specifically expressed in the MSG and that the expression level of BmSer-1 was significantly higher in the MSG than in other tissues. Recombinant plasmids carrying both pri-mir-2780a and Ser1-3'UTR were constructed and then used to cotransfect BmN cells. We further detected the effect of bmo-miR-2780a on Ser-1 in vivo. These results showed that the target gene was significantly decreased by miR-2780a compared with the control group (p < .05), thus indicating that bmo-miR-2780a might negatively regulate the expression of Ser-1.

Expression analysis and functional identification of several genes related to diapause in Bombyx mori.

Diapause is an important characteristic of insects used to adapt to extreme changes in environmental conditions. Embryonic diapause of the bivoltine silkworm (Bombyx mori) is determined by environmental conditions experienced by the mother while in the embryo stage. If they are incubated at 25°C with natural light, their progenies will be diapause-destined. If they are incubated at 17°C in darkness, their progenies will be non-diapause-destined. The molecular mechanism of diapause remains unknown. In the present study, we analyzed two downregulated genes (BGIBMGA003835, BGIBMGA012335) and two upregulated genes (BGIBMG012996, BGIBMG002426) related to carbohydrate metabolism, verified differentially expressed in ovaries and heads of 1-day-old fifth-instar larvae to 6-day pupae by quantitative real-time reverse transcription polymerase chain reaction (qRT-PCR). In line with published data, the expression level of these genes in larvae were generally lower than in pupae. We further analyzed the expression levels of the four genes in BmN cells that had been treated with various concentrations of diapause hormone (DH). It demonstrated that the expression of these genes was affected by DH. Knockdown of the selected genes in non-diapause-destined female pupae changed the fate of the progeny from non-diapause- to daipause-destined, as seen by the appearance of diapause eggs. Our study provides insight into the molecular mechanism of diapause in B. mori.

The role of N6-methyladenosine modification on diapause in silkworm (Bombyx mori) strains that exhibit different voltinism.

N6-methyladenosine (m6 A) plays a key role in regulating gene expression in myriad organisms. Diapause is an important plastic phenotype that allows insects to survive under specific environmental conditions. However, the diapause molecular mechanism remains unknown. In this study, we analyzed the phylogenetics of genes related to the m6 A modification complex in the silkworm (Bombyx mori) based on identified sequences from other organisms. We detected the expression of these genes during different developmental phases from four strains with different voltinism. We also determined total m6 A content in cells treated with different diapause hormone concentrations or eggs exposed to hydrochloric acid. Our data revealed that m6 A-modification-related gene expression and m6 A content were greater in diapause-destinated compared to nondiapause-destined strains. Our findings suggest that m6 A modification may provide significant epigenetic regulation of diapause-related genes in the silkworm.

Pathway of effects of adverse childhood experiences on the poly-drug use pattern among adults using drugs: A structural equation modeling.

Introduction: Adverse childhood experiences (ACEs) are associated with an increased risk of poly-substance use among drug-using adults. However, there is a paucity of literature on a direct or indirect relationship between ACEs and drug use patterns. We thus aimed to identify the pathway of effects of ACEs on drug use patterns in adults by the structural equation model (SEM). Methods: A cross-sectional study was conducted by respondent-driving sampling and consecutive sampling among adult drug users in Southwest China in 2021. Descriptive, univariate, and SEM analyses were performed by R software 4.2.1. Results: Of 406 participants recruited from a drug abuse clinic, the average age was 34 years. The majority of the participants were male patients (98.3%) from ethnic minorities (79.6%), who were unmarried (71.6%) and employed (81.2%). Nearly 95.5% experienced ACEs with 46.6% of them reporting four or more ACEs. The median value of self-perception of drug abuse score, friend drug use score, and drug use score was 8.0 (3.0, 11.0), 1.0 (0.0, 1.0), and 1.0 (1.0, 2.0) respectively. In the confirmatory analysis part of SEM, the construct of latent variables fitted well with the data. Poly-drug use was significantly and directly affected by three predictors including monthly incomes (ß = 0.09), friend drug use (ß = 0.50), and ACEs (ß = 0.11). The indirect effect of ACEs passing through self-perception of drugs (ß = 0.09) was not significant. Discussion: ACEs have an independent and direct effect on the drug user for poly-drug use apart from the effect of drug-using friends and family income.

Cross-border Activities Associated With Pattern of Amphetamine-type Stimulants Usage Among Drug Users in Southwest of China.

Cross-border activities are possibly associated with the use of amphetamine-type stimulants (ATS), this study was to explore poly-substance of ATS use and influencing factors among ATS use populations in southwest China. A cross-sectional study was conducted by response driven and continuous samplings from January to July 2021. Descriptive, univariate and logistic regression were carried out. ATS users accounted for 95.6% of the target population, of whom one-third had cross-border experiences with 4.1% of the cross-border purchase of drugs. ATS users were mainly over 31 years old (53.9%), male (98.7%), minority (79.1%), and unmarried (72.7%). Cross-border users consumed more ketamine (8%) and methamphetamine (40%) (P < .05). After adjusting for socioeconomic-demographic factors, cross-border activity [OR: 0.336 (0.141, 0.799)], occupation [OR: 0.273 (0.080, 0.929)], injecting drug behavior [OR: 6.239 (1. 087, 35.811)], frequency [OR: 0.251 (0.073, 0.859)], and ATS use location [OR: 2.915 (1.040, 8.168)] were possible factors influencing ATS use patterns (P < .05). Cross-border activity may be associated with polydrug use, especially predominantly methamphetamine use, among ATS users along the Southwest border. It implied that the focus of drug prevention and control in border areas should be on cross-border populations.

Identification and Characterization of Genes Related to Resistance of Autographa californica Nucleopolyhedrovirus Infection in Bombyx mori.

In Bombyx mori, as an important economic insect, it was first found that some strains were completely refractory to infection with Autographa californica nucleopolyhedrovirus (AcMNPV) through intrahemocelical injection; whereas almost all natural strains had difficulty resisting Bombyx mori nucleopolyhedrovirus (BmNPV), which is also a member of the family Baculoviridae. Previous genetics analysis research found that this trait was controlled by a potentially corresponding locus on chromosome 3, but the specific gene and mechanism was still unknown. With the help of the massive silkworm strain re-sequencing dataset, we performed the Genome-Wide Association Studies (GWAS) to identify the gene related to the resistance of AcMNPV in this study. The GWAS results showed that the Niemann-Pick type C1 (NPC-1) gene was the most associated with the trait. The knockdown experiments in BmN cells showed that BmNPC1 has a successful virus suppression infection ability. We found a small number of amino acid mutations among different resistant silkworms, which indicates that these mutations contributed to the resistance of AcMNPV. Furthermore, inhibition of the BmNPC1 gene also changed the viral gene expression of the AcMNPV, which is similar to the expression profile in the transcriptome data of p50 and C108 strains.

Amphetamine-type stimulants use and socio-economic factors associated with hepatitis C antibody positivity among border drug users in South of China.

Background: Amphetamine-type stimulants (ATS) use has become popular in China. This study explored ATS use status and related risk factors of hepatitis C virus (HCV) infection among ATS users in Jinghong City, Xishuangbanna Prefecture, Yunnan Province, China. Methods: A cross-sectional study was conducted by questionnaires from January to July 2021 in border area in Yunnan. Respondent driving sampling and consecutive sampling was carried out among border drug users, and blood samples were tested for HCV antibodies. HCV infection and related risk factors among ATS users were measured. Descriptive, univariate and multivariate analysis were conducted separately by Software SPSS 26.0. Results: The ATS users accounted for 85.82% (345/402) among drug users, while anti-HCV antibody prevalence was 6.38% (22/345) among ATS users. The combined use of other types of drugs (OR = 7.29, 95%CI: 1.982-26.81, P = 0.003), injection drug use (OR = 6.823, 95%CI: 1.898-24.525, P = 0.003), average monthly income (OR = 4.825, 95%CI: 1.325-17.566, P = 0.017) might increase the risk of HCV infection among ATS users. ATS users with high school or above had higher HCV infection rates than those with primary school or below (OR = 5.718, 95%CI: 1.172-27.908, P = 0.031). Conclusion: Taken together, among drug users using ATS in Jinghong City, Xishuangbanna Autonomous Prefecture, Yunnan Province, combined use of multiple drugs and intravenous drug use was the high risk factor for HCV infection. Therefore, corresponding education and intervention measures should be taken.

Biomimetic Solid-Liquid Transition Structural Dye-Doped Liquid Crystal/Phase-Change-Material Microcapsules Designed for Wearable Bistable Electrochromic Fabric.

A novel polymer microcapsule-filled dye-doped liquid crystal (DDLC) and phase-change material (PCM) system inspired by biological materials was first proposed, which was further encapsulated into a calcium alginate substrate by wet spinning for making an electrochromic fiber with both bistable electric-optical capability and knitting characteristics. Results show that the optical appearance of the optimized microcapsules and fiber can be reversibly changed between colored and colorless states according to the electric field by switching the DDLCs between isotropic (I) and anisotropic (A) states. Moreover, both I and A states can remain stable for more than 1 week after removing the electric field, due to the synergy of the greatly increased spatial hindrance of the PCM with core loading of 22.58% and the confinement effect from the polymer microcapsule shell material. Aside from the long-term optical stability, the high content of the densely packed DDLCs also endows the electrochromic fiber with a satisfactory driving voltage of 9.7 V, which is below the human safe voltage, showing great potential in a wide range of applications, such as flexible displays, energy-saving smart windows, and wearable advanced textiles.

Bistable Elastic Electrochromic Ionic Gels for Energy-Saving Displays.

The diversification of electrochromic materials greatly expands the application fields of electrochromic devices. However, highly flexible electrochromic materials remain challenging due to the inherent limitations associated with the existing electrochromic processes. Inspired by the hydrogen bonding effect in the hydrogel structure, a highly elastic and bistable electrochromic ionic gel based on a hydrogen bonding cross-linking network is prepared by solution polymerization having excellent tensile resilience, uniform coloring, reversible switching (≤24.3 s), maximum transmittance change (≥80%), bistability (54 h), reversibility (>500 cycles), and coloration efficiency (≥85.3 cm2·C-1). This method has been used to develop bistable electrochromic displays. The unconventional exploration of the bistable design principle may provide a new idea for the realization of bistable electrochromic devices.

A highly selective and reversible turn-off fluorescent chemosensor for Cu2+ based on electrospun nanofibrous membrane modified with pyrenecarboxaldehyde.

A fluorescent nanofibrous membrane (NFM) was successfully fabricated by functionalizing electrospun ethylene-vinyl alcohol copolymer (EVOH) NFM with 4­aminobenzoic acid (PABA) and 1­pyrenecarboxaldehyde (Py-CHO) for fast and selective determination of Cu2+ in aqueous solution. The effective grafting of PABA and Py-CHO on the surface of EVOH NFM was confirmed by FTIR and XPS spectra. Benefiting from the integrated merits of electrospun EVOH NFM, PABA and Py-CHO, the as-appeared EVOH-PABA-Py NFM exhibited high sensitivity and selectivity towards Cu2+ detection. The quenching efficiency was 91.7% when the concentration of Cu2+ reached 5 × 10-3 M, while the detectable fluorescence response of the NFM was still observed when the concentration of Cu2+ was 1 × 10-9 M. The fluorescence quenching caused by Cu2+ was hardly affected by other commonly co-existent metal ions. More importantly, the fluorescent NFM exhibited fast response and high reversibility towards Cu2+ detection. The "off-on" fluorescence switching process via alternating addition of Cu2+ and Na2EDTA occurred in 3 min, and the quenching efficiency of the NFM kept relatively stable values within 10 cycles. This work may provide a new insight into the development of rapid, portable, stable and reusable fluorescent sensor based on electrospun nanofibers that can satisfy the requirements of practical metal ions detection.