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Abstract 3-Hydroxy-3-methyl glutaryl coenzyme A reductase (HMGR) is an important rate-limiting enzyme in the mevalonate pathway, which is critical for the synthesis of juvenile hormone and insect development. In this study, a full-length cDNA encoding HMGR ( BdHMGR ) was cloned from the oriental fruit fly, Bactrocera dorsalis (Hendel). The open reading frame of BdHMGR encoded 928 amino acids and shared a high degree of identity with other known HMGRs. The expression levels of BdHMGR were high during the early and lately pupal stages, and were low at the larval and mid pupal stages. In the adult stages, the highest level of BdHMGR was detected on day-10 of the adult lifecycle, and the expression levels in females were greater than those in males. The highest tissue-specific expression was in the ovary, followed by fat body and other tissues. Injection of double-stranded RNA (dsRNA) of BdHMGR into adult females significantly reduced BdHMGR transcript levels, and inhibited ovarian development and affected the expression of two yolk protein genes. After dissection, we found that one or two of the spheroids of ovaries from the BdHMGR dsRNA-injected flies were amorphous and reduced in size as compared with the controls. The results suggest that BdHMGR is required for ovarian development in B. dorsalis and may be a potential target for pest control. Graphical abstract Unlabelled Image Highlights • A HMGR gene was identified in Bactrocera dorsalis. • BdHMGR was highly expressed in the pupal and adult stages. • BdHMGR was mainly distributed in the ovary. • BdHMGR is potentially involved in ovarian development. [ABSTRACT FROM AUTHOR]

Chitin deacetylases (CDAs) are chitin degradation enzymes that strictly regulate growth and development in insects. In this study, we identified and characterized a full-length cDNA of the CDA gene ( SpCDA1 ) in the drugstore beetle, Stegobium paniceum . The open reading frame of SpCDA1 (1614 bp) encoded a 537 amino acid protein, which possessed typical domain structures of CDAs. Phylogenetic comparison to other insect CDAs revealed that SpCDA1 belongs to Group Ib CDAs. Quantitative real-time PCR analyses showed that SpCDA1 was highly expressed in late larval stages. Significant increase of SpCDA1 transcript level in the larvae was observed upon the exposure of 20-hydroxyecdysone. Injection of double-stranded RNA (dsRNA) of SpCDA1 into the late larvae significantly reduced SpCDA1 transcript levels, resulted in larval-pupal molting difficulty and produced high larval mortality. After 15 days, the survival rate of S. paniceum in ds SpCDA1 group was significantly reduced by 72% compared to the control. The results demonstrated that SpCDA1 is essential for successful larval-pupal transition in S. paniceum and this gene may be a potential target for pest control. [ABSTRACT FROM AUTHOR]

In this paper, a dual least squares support vector machines (LS-SVM) is proposed to model the thermal process. The infinite-dimensional system is first transformed into a finite-dimensional system through space-time separation. Then, the dual LS-SVM model is to approximate the two nonlinearities embedded in the system. Through space-time synthesis, the dual LS-SVM based spatiotemporal model is able to approximate the complex DPS with inherent coupled nonlinearities. The generalization performance of the proposed model is discussed using Rademacher complexity. Finally, simulations on a curing process demonstrate the effectiveness of the proposed modeling method. [ABSTRACT FROM AUTHOR]

The forkhead box O transcription factor ( FoxO ) is an important downstream transcription factor in the well-conserved insulin signaling pathway, which regulates the body size and development of insects. In this study, the FoxO gene ( BdFoxO ) was identified from the oriental fruit fly, Bactrocera dorsalis (Hendel). The open reading frame of BdFoxO (2732 bp) encoded a 910 amino acid protein, and the sequence was well conserved with other insect species. The BdFoxO was highly expressed in larvae and pupae among different development stages, and the highest tissue-specific expression level was found in the fat bodies compared to the testis, ovary, head, thorax, midgut, and Malpighian tubules of adults. Interestingly, we found BdFoxO expression was also up-regulated by starvation, but down-regulated when re-fed. Moreover, the injection of BdFoxO double-stranded RNAs into third-instar larvae significantly reduced BdFoxO transcript levels, which in turn down-regulated the expression of other four genes in the insulin signaling pathway. The silencing of BdFoxO resulted in delayed pupation, and the insect body weight increased significantly compared with that of the control. These results suggested that BdFoxO plays an important role in body size and development in B. dorsalis . [ABSTRACT FROM AUTHOR]