Two insulin receptors determine alternative wing morphs in planthoppers.

Wing polyphenism is an evolutionarily successful feature found in a wide range of insects. Long-winged morphs can fly, which allows them to escape adverse habitats and track changing resources, whereas short-winged morphs are flightless, but usually possess higher fecundity than the winged morphs. Studies on aphids, crickets and planthoppers have revealed that alternative wing morphs develop in response to various environmental cues, and that the response to these cues may be mediated by developmental hormones, although research in this area has yielded equivocal and conflicting results about exactly which hormones are involved. As it stands, the molecular mechanism underlying wing morph determination in insects has remained elusive. Here we show that two insulin receptors in the migratory brown planthopper Nilaparvata lugens, InR1 and InR2, have opposing roles in controlling long wing versus short wing development by regulating the activity of the forkhead transcription factor Foxo. InR1, acting via the phosphatidylinositol-3-OH kinase (PI(3)K)-protein kinase B (Akt) signalling cascade, leads to the long-winged morph if active and the short-winged morph if inactive. InR2, by contrast, functions as a negative regulator of the InR1-PI(3)K-Akt pathway: suppression of InR2 results in development of the long-winged morph. The brain-secreted ligand Ilp3 triggers development of long-winged morphs. Our findings provide the first evidence of a molecular basis for the regulation of wing polyphenism in insects, and they are also the first demonstration--to our knowledge--of binary control over alternative developmental outcomes, and thus deepen our understanding of the development and evolution of phenotypic plasticity.

Thickness-Dependent Resistive Switching Behavior of KCu7S4/CuxO/Au Device.

We report the fabrication of KCu7S4/CuxO/Au devices with interfacial CuxO layers of different thicknesses through the spontaneous oxidation of Cu film during deposition. Deposition was conducted with an electron-beam evaporation system under the deposition rate and the chamber pressure of 0.1 Å s-1 and 9.8×10-3 Pa, respectively. X-ray diffraction and X-ray photoelectron spectroscopy characterizations reveal that the interfacial CuxO layers mostly comprise Cu2O and CuO. Electrical characterization reveals that the devices exhibit remarkably thickness-dependent resistive switching behavior. After undergoing an electroforming process under a high compliant current of 1000 µA, the KCu7S4/16 nm CuxO/Au device exhibits stable bipolar resistive switching behavior with the set voltage of 0.58 V and reset voltage of -0.21 V, whereas the KCu7S4/32 nm CuxO/Au device only shows a hysteresis loop in the forward voltage regime. These findings are ascribed to the existence of high-insulation CuO, which is difficult to be softly broken down. Therefore, the depositional condition of Cu film and the thickness of the interfacial layer should be appropriately controlled for the effective performance of devices with Cu electrodes. The results may also provide guidance for the improvement of the performance and stability of Cu-based nonvolatile memory devices.

Hexagonal Monolayer Ice without Shared Edges.

When adsorbed on solids, water molecules are usually arranged into a honeycomb hydrogen-bond network. Here we report the discovery of a novel monolayer ice built exclusively from water hexamers but without shared edges, distinct from all conventional ice phases. Water grown on graphite crystalizes into a robust monolayer ice after annealing, attaining an exceedingly high density of 0.134 Å^{-2}. Unlike chemisorbed ice on metal surfaces, the ice monolayer can translate and rotate on graphite terraces and grow across steps, confirming its two-dimensional nature. First-principles calculations identify the monolayer ice structure as a robust self-assembly of closely packed water hexamers without edge sharing, whose stability is maintained by maximizing the number of intralayer hydrogen bonds on inert surfaces.

Brown planthopper nudivirus DNA integrated in its host genome.

UNLABELLED: The brown planthopper (BPH), Nilaparvata lugens (Hemiptera:Delphacidae), is one of the most destructive insect pests of rice crops in Asia. Nudivirus-like sequences were identified during the whole-genome sequencing of BPH. PCR examination showed that the virus sequences were present in all of the 22 BPH populations collected from East, Southeast, and South Asia. Thirty-two of the 33 nudivirus core genes were identified, including 20 homologues of baculovirus core genes. In addition, several gene clusters that were arranged collinearly with those of other nudiviruses were found in the partial virus genome. In a phylogenetic tree constructed using the supermatrix method, the original virus was grouped with other nudiviruses and was closely related to polydnavirus. Taken together, these data indicated that the virus sequences belong to a new member of the family Nudiviridae. More specifically, the virus sequences were integrated into the chromosome of its insect host during coevolution. This study is the first report of a large double-stranded circular DNA virus genome in a sap-sucking hemipteran insect. IMPORTANCE: This is the first report of a large double-stranded DNA virus integrated genome in the planthopper, a plant sap-sucking hemipteran insect. It is an exciting addition to the evolutionary story of bracoviruses (polydnaviruses), nudiviruses, and baculoviruses. The results on the virus sequences integrated in the chromosomes of its insect host also represent a story of successful coevolution of an invertebrate virus and a plant sap-sucking insect.

Urinary Proteomics Analysis of Active Vitiligo Patients: Biomarkers for Steroid Treatment Efficacy Prediction and Monitoring.

Vitiligo is a common acquired skin disorder caused by immune-mediated destruction of epidermal melanocytes. Systemic glucocorticoids (GCs) have been used to prevent the progression of active vitiligo, with 8.2-56.2% of patients insensitive to this therapy. Currently, there is a lack of biomarkers that can accurately predict and evaluate treatment responses. The goal of this study was to identify candidate urinary protein biomarkers to predict the efficacy of GCs treatment in active vitiligo patients and monitor the disease. Fifty-eight non-segmental vitiligo patients were enrolled, and 116 urine samples were collected before and after GCs treatment. Patients were classified into a treatment-effective group (n = 42) and a treatment-resistant group (n = 16). Each group was divided equally into age- and sex-matched experimental and validation groups, and proteomic analyses were performed. Differentially expressed proteins were identified, and Ingenuity Pathway Analysis was conducted for the functional annotation of these proteins. Receiver operating characteristic curves were used to evaluate the diagnostic value. A total of 245 and 341 differentially expressed proteins between the treatment-resistant and treatment-effective groups were found before and after GCs treatment, respectively. Bioinformatic analysis revealed that the urinary proteome reflected the efficacy of GCs in active vitiligo patients. Eighty and fifty-four candidate biomarkers for treatment response prediction and treatment response evaluation were validated, respectively. By ELISA analysis, retinol binding protein-1 and torsin 1A interacting protein 1 were validated to have the potential to predict the efficacy of GCs with AUC value of 1 and 0.875, respectively. Retinol binding protein-1, torsin 1A interacting protein 1 and protein disulfide-isomerase A4 were validated to have the potential to reflect positive treatment effect to GCs treatment in active vitiligo with AUC value of 0.861, 1 and 0.868, respectively. This report is the first to identify urine biomarkers for GCs treatment efficacy prediction in vitiligo patients. These findings might contribute to the application of GCs in treating active vitiligo patients.

Opening the Band Gap of Graphene via Fluorination for High-Performance Dual-Mode Photodetector Application.

Fluorination is an effective process to open the band gap of graphene (Gr), which is beneficial to the development of optoelectronic devices working in wide wavelength. Herein, we report a dual-mode broadband photodetector (PD) by integrating fluorinated graphene (F-Gr) with silicon (Si). It is found that when working in photoconductive mode, the F-Gr/Si heterojunction exhibited a remarkable photoresponse over a wide spectral region from ultraviolet (UV), visible to near infrared (NIR) light with a high responsivity ( R) of 1.9 × 107 A W-1 and specific detectivity ( D*) of 4.4 × 1012 Jones at 650 nm. Nonetheless, both parameters will be considerably reduced when the F-Gr/Si heterojunction works in the photodiode mode. In this mode, the Ilight/ Idark ratio is as high as 2.0 × 105 and the response speed is accelerated by more than 3 orders of magnitude from about 5 ms to 6.3 µs. Notably, the responsivity of the device in the UV and NIR regions was remarkably enhanced in comparison with that of pristine Gr/Si-heterojunction-based devices. Considering the F-coverage-dependent band gap of the F-Gr revealed by the first-principle calculations, we believe that the enhancement was ascribed to the opening of the band gap in the partially fluorinated Gr, which is stabilized due to the configuration entropy as the temperature increases. The dual-mode PD enabled the simultaneous weak light detection and fast photodetection, which overcome the limitation of the traditional monomode PD.

Forkhead box transcription factor L2 activates Fcp3C to regulate insect chorion formation.

Most animals are oviparous. However, the genes regulating egg shell formation remain not very clear. In this study, we found that Nilaparvata lugens Forkhead box transcription factor L2 (NlFoxL2) directly activated follicle cell protein 3C (NlFcp3C) to regulate chorion formation. NlFoxL2 and NlFcp3C had a similar expression pattern, both highly expressed in the follicular cells of female adults. Knockdown of NlFoxL2 or NlFcp3C also resulted in the same phenotypes: obesity and female infertility. RNA interference (RNAi) results suggested that NlFcp3C is a downstream gene of NlFoxL2 Furthermore, transient expression showed that NlFoxL2 could directly activate the NlFcp3C promoter. These results suggest that NlFcp3C is a direct target gene of NlFoxL2. Depletion of NlFoxL2 or NlFcp3C prevented normal chorion formation. Our results first revealed the functions of Fcp3C and FoxL2 in regulation of oocyte maturation in an oviparous animal.