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High fecundity is a common characteristic of insect pests which increases the difficulty of population control. Serine/threonine kinase Akt is an indispensable component of the insulin signaling pathway. Silencing of LsAkt severely hinders reproduction in Lasioderma serricorne, a stored product insect pest. However, the post‐transcriptional pathway of LsAkt in L. serricorne remains unknown. This study identified 2 binding sites of miR‐9c‐5p and novel‐mir50 in the coding sequences of LsAkt. The expression profiles of 2 microRNAs (miRNAs) and LsAkt displayed an opposite pattern during the adult stages. Luciferase reporter assay showed that novel‐mir50 and miR‐9c‐5p could downregulate the expression of LsAkt. Overexpression of miR‐9c‐5p and novel‐mir50 by injection of mimics inhibited the expression of LsAkt and reduced oviposition, decreased egg hatchability, and blocked ovarian development. It also decreased the expression of genes involved in ovarian development (LsVg and LsVgR) and the nutritional signaling pathway (LsTOR, LsS6K, and Ls4EBP), and reduced the phosphorylation of Akt. Conversely, injection of miR‐9c‐5p and novel‐mir50 inhibitors induced the expressions of LsAkt, LsVg, LsVgR, LsTOR, LsS6K, and Ls4EBP, enhanced Akt phosphorylation level, and accelerated ovarian development. Injection of bovine insulin downregulated the expression of miR‐9c‐5p and novel‐mir50 and upregulated the LsAkt expression. It also rescued the reproductive development defects associated with miR‐9c‐5p/novel‐mir50 overexpression, forming a positive regulatory loop of insulin signaling. These results indicate that miR‐9c‐5p/novel‐mir50 regulates the female reproduction of L. serricorne by targeting Akt in response to insulin signaling. The data also demonstrate the effects of the insulin/miRNA/Akt regulatory axis in insect reproduction. [ABSTRACT FROM AUTHOR]

Cytochrome P450 monooxygenase (CYP) is one of the three detoxification metabolic enzymes in insects, and is involved in the metabolism and transformation of endogenous substances as well as the activation and degradation of exogenous compounds. This study aims to reveal the molecular mechanism of CYP9E2 in Tribolium castaneum in adapting to high-CO2 stress. By predicting the sequence function of CYP9E2, analyzing the temporal and spatial expression profile of TcCYP9E2, and using RNAi to silence TcCYP9E2 combined with a high-CO2 stress treatment, we measured the carbohydrate content, trehalase activity, and gene expression levels in trehalose metabolism of T. castaneum. A bioinformatics analysis showed that the predicted molecular weight of the protein encoded by TcCYP9E2 is 60.15, the theoretical isoelectric point is 8.63, there is no signal peptide, and the protein is hydrophilic. An evolutionary tree analysis showed that TcCYP9E2 belongs to the CYP6 family and belongs to the CYP3 group; and the spatiotemporal expression profile results showed that TcCYP9E2 was highly expressed in the larvae midgut 48 h after injection of dsCYP9E2, with survival rates decreasing with the increase in CO2 concentration. Under the condition of 75% CO2, the contents of glycogen, glucose, ATP, and membrane-bound trehalase decreased significantly after the injection of dsCYP9E2. The expression of TRE-1, TRE-2, and GP in trehalose metabolism and energy pathways was significantly downregulated. [ABSTRACT FROM AUTHOR]

Many industrial thermal processes belong to distributed parameter systems (DPSs), which have two coupled nonlinear blocks. Dual least square support vector machines (LS-SVM) has been proposed to model such systems. However, due to the use of two LS-SVM, this method often leads to heavy computation and long learning time, which does not suit for online application. In this study, a dual extreme learning machine (ELM)-based spatiotemporal modeling method is proposed for such two nonlinearities embedded DPSs. Firstly, the KL method is applied to reduce the dimension of the original system and obtain the spatial basis functions (BFs). Then, dual ELM is designed to match the two nonlinear structures. Finally, through the reconstruction of space–time synthesis, the approximate spatiotemporal distribution model of the original system is obtained. In addition, simulations on a curing process is studied to confirm the effectiveness of the proposed method. [ABSTRACT FROM AUTHOR]

Clip-domain serine proteases (CLIPs) play crucial roles in insect development and innate immunity. In this study, we identified a CLIP gene (designated Ls CLIP3) from the cigarette beetle Lasioderma serricorne. Ls CLIP3 contains a 1,773-bp open reading frame (ORF) encoding a 390-amino-acid protein and shows a conserved clip domain and a trypsin-like serine protease domain. Phylogenetic analysis indicated that Ls CLIP3 was orthologous to the CLIP-B subfamily. Ls CLIP3 was prominently expressed in larva, pupa, and early adult stages. In larval tissues, it was highly expressed in the integument and fat body. The expression of Ls CLIP3 was induced by 20-hydroxyecdysone. A similar induction was also found by peptidoglycans from Escherichia coli and Staphylococcus aureus. RNA interference (RNAi)-mediated silencing of Ls CLIP3 disrupted larval–pupal molting and specifically reduced the expression of genes in 20-hydroxyecdysone synthesis and signaling pathway. The chitin amounts of Ls CLIP3 RNAi larvae were greatly decreased, and expressions of six chitin metabolic-related genes were significantly reduced. Knockdown of Ls CLIP3 increased larval sensitivity to Gram-negative and Gram-positive bacteria. There was significantly decreased expression of four antimicrobial peptide (AMP) genes. The results suggest that Ls CLIP3 is an important component of the larva to pupa molt and for the immunity of L. serricorne. [ABSTRACT FROM AUTHOR]