RNAi of yellow-y, required for normal cuticle pigmentation, impairs courtship behavior and oviposition in the German cockroach (Blattella germanica).

The insect cuticle plays a key role in maintaining the insect's physiological function and behavior. Herein, the yellow-y protein is required to produce black melanin, and is expressed in a pattern that correlates with the distribution of this pigment. However, yellow-y can also have other functions, for instance, in insect behavior, but not much is known. In this study, we have studied the yellow-y gene in one important model and pest species, namely the German cockroach (Blattella germanica), which is to our knowledge the first time reported. In essence, we identified the yellow-y gene (BgY-y) and characterized its function by using RNA interference (RNAi). Silencing of BgY-y gene led to different developmental abnormalities (body weight and wings) in both genders. Specifically, there was an abundant decrease in melanin, turning the body color in pale yellow and the cuticle softer and more transparent. Interestingly, we also observed that the knockdown of BgY-y impaired the male cockroaches to display a weaker response to female-emitted contact sex pheromones, and also that the oviposition ability was weakened in the RNAi females. This study comprehensively analyzed the biological functions of the yellow-y gene in German cockroaches from the perspectives of development, body color, courtship behavior and oviposition, and as a consequence, this may opens new avenues to explore it as a novel pest control gene.

The melanin pigment gene black mediates body pigmentation and courtship behaviour in the German cockroach Blattella germanica.

Genes involved in melanin production directly impact insect pigmentation and can affect diverse physiology and behaviours. The role these genes have on sex behaviour, however, is unclear. In the present study, the crucial melanin pigment gene black was functionally characterised in an urban pest, the German cockroach, Blattella germanica. RNAi knockdown of B. germanica black (Bgblack) had no effect on survival, but did result in black pigmentation of the thoraxes, abdomens, heads, wings, legs, antennae, and cerci due to cuticular accumulation of melanin. Sex-specific variation in the pigmentation pattern was apparent, with females exhibiting darker coloration on the abdomen and thorax than males. Bgblack knockdown also resulted in wing deformation and negatively impacted the contact sex pheromone-based courtship behaviour of males. This study provides evidence for black function in multiple aspects of B. germanica biology and opens new avenues of exploration for novel pest control strategies.

Nanoparticle-delivered RNAi-based pesticide target screening for the rice pest white-backed planthopper and risk assessment for a natural predator.

Vacuolar-type (H+)-ATPase (vATPase) is a conserved multi-subunit eukaryotic enzyme composed of 14 subunits that form a functional complex consisting of an ATP-hydrolytic domain (V1) and a proton-translocation domain (V0). ATP hydrolysis and subsequent H+ translocation rely heavily on a fully assembled V1/V0 complex. Since vATPase is crucial for insect survival, it is a viable molecular target for pest control. However, detailed functional analyses of the 14 subunits and their suitability for pest control have not been fully explored in a single insect species. In this study, we identified 22 vATPase subunit transcripts that correspond to 13 subunits (A1, A2, B, C, D, E, F, G, H, a1, a2, c and d) in the white-backed planthopper (WBPH), Sogatella furcifera, a major hemipteran pest of rice. RNAi screens using microinjection and spray-based methods revealed that the SfVHA-F, SfVHA-a2 and SfVHA-c2 subunits are critical. Furthermore, star polymer (SPc) nanoparticles were utilized to conduct spray-induced and nanoparticle-delivered gene silencing (SI-NDGS) to evaluate the pest control efficacy of RNAi targeting the SfVHA-F, SfVHA-a2 and SfVHA-c2 transcripts. Target mRNA levels and vATPase enzymatic activity were both reduced. Honeydew excreta was likewise reduced in WBPH treated with dsRNAs targeting SfVHA-F, SfVHA-a2 and SfVHA-c2. To assess the environmental safety of the nanoparticle-wrapped dsRNAs, Cyrtorhinus lividipennis Reuter, a major natural enemy of planthoppers, was also sprayed with dsRNAs targeting SfVHA-F, SfVHA-a2 and SfVHA-c2. Post-spray effects of dsSfVHA-a2 and dsSfVHA-c2 on C. lividipennis were innocuous. This study identifies SfVHA-a2 and SfVHA-c2 as promising targets for biorational control of WBPH and lays the foundation for developing environment-friendly RNAi biopesticides.

RNA Interference-Screening of Potentially Lethal Gene Targets in the White-Backed Planthopper Sogatella furcifera via a Spray-Induced and Nanocarrier-Delivered Gene Silencing System.

RNA interference (RNAi) is a widespread post-transcriptional silencing mechanism that targets homologous mRNA sequences for specific degradation. An RNAi-based pest management strategy is target-specific and considered a sustainable biopesticide. However, the specific genes targeted and the efficiency of the delivery methods can vary widely across species. In this study, a spray-induced and nanocarrier-delivered gene silencing (SI-NDGS) system that incorporated gene-specific dsRNAs targeting conserved genes was used to evaluate phenotypic effects in white-backed planthopper (WBPH). At 2 days postspraying, transcript levels for all target genes were significantly reduced and knockdown of two gene orthologs, hsc70-3 and PP-α, resulted in an elevated mortality (>60%) and impaired ecdysis. These results highlight the utility of the SI-NDGS system for identifying genes involved in WBPH growth and development that could be potentially exploitable as high mortality target genes to develop an alternative method for WBPH control.

The IRF2/CENP-N/AKT signaling axis promotes proliferation, cell cycling and apoptosis resistance in nasopharyngeal carcinoma cells by increasing aerobic glycolysis.

BACKGROUND: Centromere protein N (CENP-N) has been reported to be highly expressed in malignancies, but its role and mechanism in nasopharyngeal carcinoma (NPC) are unknown. METHODS: Abnormal CENP-N expression from NPC microarrays of GEO database was analyzed. CENP-N expression level was confirmed in NPC tissues and cell lines. Stable CENP-N knockdown and overexpression NPC cell lines were established, and transcriptome sequencing after CENP-N knockdown was performed. In vitro and in vivo experiments were performed to test the impact of CENP-N knockdown in NPC cells. ChIP and dual luciferase reporter assays were used to verify the combination of IRF2 and CENP-N. Western blot analysis, cellular immunofluorescence, immunoprecipitation and GST pulldown assays were used to verify the combination of CENP-N and AKT. RESULTS: CENP-N was confirmed to be aberrantly highly expressed in NPC tissues and cell lines and to be associated with high 18F-FDG uptake in cancer nests and poor patient prognosis. Transcriptome sequencing after CENP-N knockdown revealed that genes with altered expression were enriched in pathways related to glucose metabolism, cell cycle regulation. CENP-N knockdown inhibited glucose metabolism, cell proliferation, cell cycling and promoted apoptosis. IRF2 is a transcription factor for CENP-N and directly promotes CENP-N expression in NPC cells. CENP-N affects the glucose metabolism, proliferation, cell cycling and apoptosis of NPC cells in vitro and in vivo through the AKT pathway. CENP-N formed a complex with AKT in NPC cells. Both an AKT inhibitor (MK-2206) and a LDHA inhibitor (GSK2837808A) blocked the effect of CENP-N overexpression on NPC cells by promoting aerobic glycolysis, proliferation, cell cycling and apoptosis resistance. CONCLUSIONS: The IRF2/CENP-N/AKT axis promotes malignant biological behaviors in NPC cells by increasing aerobic glycolysis, and the IRF2/CENP-N/AKT signaling axis is expected to be a new target for NPC therapy.

Melanin-based nanomaterials: The promising nanoplatforms for cancer diagnosis and therapy.

Melanin-based nanoplatforms are biocompatible nanomaterials with a variety of unique physicochemical properties such as strong photothermal conversion ability, excellent drug binding capacity, strong metal chelation capacity, high chemical reactivity and versatile adhesion ability. These innate talents not only make melanin-based nanoplatforms be an inborn theranostic nanoagent for photoacoustic imaging-guided photothermal therapy of cancers, but also enable them to be conveniently transferred into cancer-targeting drug delivery systems and multimodality imaging nanoprobes. Due to the intriguing properties, melanin-based nanoplatforms have attracted much attention in investigations of cancer diagnosis and therapy. This review provides an overview of recent research advances in applications of melanin-based nanoplatforms in the fields of cancer diagnosis and therapy including cancer photothermal therapy, anticancer drug delivery, cancer-specific multimodal imaging and theranostics, etc. The remaining challenges and prospects of melanin-based nanoplatforms in biomedical applications are discussed at the end of this review.

[Research on SCB discharge behavior with atomic emission spectroscopy].

Semiconductor bridge (SCB) was utilized to ignite energetic materials with thin film discharge and characterized of low input energy, high safety and logic control possibility. SCB discharge was diagnosticated with atomic emission spectroscopy. Firstly, discharge temperature was acquired with copper atom spectral lines 510.5 and 521.8 nm, and electron density was calculated with silicon atom spectral line 390.5 nm and corresponding ion line 413.0 nm. As for resistance 1.0 omega of SCB with the discharge voltage of 20 V and capacity of 47 microF, its discharge temperature was about 2 500-4 300 K and electron density 10(16) cm(-3). Meanwhile, the temperature and density V(s) time distributions were acquired simultaneously. And then with the diagnosis results, the discharge behaviors of two sorts of SCB were judged according to plasma space-dimension and time-dimension restrictions. This research set up an efficient technique for the diagnosis of transient small-size discharge behavior and provided instructions for the design of SCB and discharge condition.

[Emission spectroscopy diagnostics of plasma electron temperature].

Electron temperature is one of the important parameters of plasma. It is very difficult to measure the electron temperature exactly and instantly owing to its complexity during discharge. As a plasma diagnostics technique, emission spectroscopy is widely applied in the study and diagnosis of any kind of plasma, because of its simple instrument system, noninterference of measurement, high sensitivity and fast responsibility. In the present paper, some methods for plasma electron temperature diagnosis, such as two lines method, multiline slope method, isoelectronic line method, Saha-Boltzmann equation, absolute intensity method, were introduced. And the applications of these methods were reviewed to provide reference for choosing appropriate methods in practice.