The oriental fruit fly, Bactrocera dorsalis, is a destructive pest in tropical and subtropical areas. In this study, we performed transcriptome-wide analysis of the fat body of B. dorsalis and obtained more than 59 million sequencing reads, which were assembled into 27,787 unigenes with an average length of 591 bp. Among them, 17,442 (62.8%) unigenes matched known proteins in the NCBI database. The assembled sequences were further annotated with gene ontology, cluster of orthologous group terms, and Kyoto encyclopedia of genes and genomes. In depth analysis was performed to identify genes putatively involved in immunity, detoxification, and energy metabolism. Many new genes were identified including serpins, peptidoglycan recognition proteins and defensins, which were potentially linked to immune defense. Many detoxification genes were identified, including cytochrome P450s, glutathione S-transferases and ATP-binding cassette (ABC) transporters. Many new transcripts possibly involved in energy metabolism, including fatty acid desaturases, lipases, alpha amylases, and trehalose-6-phosphate synthases, were identified. Moreover, we randomly selected some genes to examine their expression patterns in different tissues by quantitative real-time PCR, which indicated that some genes exhibited fat body-specific expression in B. dorsalis. The identification of a numerous transcripts in the fat body of B. dorsalis laid the foundation for future studies on the functions of these genes.

Glucose-6-phosphate isomerase (G6PI) and UDP-N-acetylglucosamine pyrophosphorylase (UAP), two key components in the chitin biosynthesis pathway, are critical for insect growth and metamorphosis. In this study, we identified the genes BdG6PI and BdUAP from the oriental fruit fly, Bactrocera dorsalis (Hendel). The open reading frames (ORFs) of BdG6PI (1,491 bp) and BdUAP (1,677 bp) encoded 496 and 558 amino acid residues, respectively. Multiple sequence alignments showed that BdG6PI and BdUAP had high amino acid sequence identity with other insect homologues. Quantitative real-time polymerase chain reaction (qPCR) analysis indicated that BdG6PI was mainly expressed in the early stages of third-instar larvae and adults, while significantly higher expression of BdUAP was observed in adults. Both transcripts were expressed highly in the Malpighian tubules, but only slightly in the tracheae. The expression of both BdG6PI and BdUAP was significantly up-regulated by 20-hydroxyecdysone exposure and down-regulated by starvation. Moreover, injection of double-stranded RNAs of BdG6PI and BdUAP into third-instar larvae significantly reduced the corresponding gene expressions. Additionally, silencing of BdUAP resulted in 65% death and abnormal phenotypes of larvae, while silencing of BdG6PI had a slight effect on insect molting. These findings provide some data on the roles of BdG6PI and BdUAP in B. dorsalis and demonstrate the potential role for BdUAP in larval-pupal transition.

Esophageal squamous cell carcinoma (ESCC) is highly prevalent in Asia, especially in China. Research findings indicate that nitrosamines, malnutrition, unhealthy living habits, and genetics contribute to esophageal carcinogenesis. Currently, the 5-year survival rate for ESCC patients remains low, owing in part to a lack of a clear understanding of mechanisms involved. Chemoprevention using natural or synthesized compounds might be a promising strategy to reduce esophageal cancer incidence. The epidermal growth factor receptor (EGFR) can activate downstream pathways including the phosphatidylinositol 3-kinase (PI3K) pathway and the Ras/mitogen-activated protein kinase (MAPK) pathways. Among the important players, AKT and ERKs have an important relationship with cancer initiation and progression. Here, we found that phosphorylated (p)-AKT and p-ERKs were highly expressed in esophageal cancer cell lines and in esophageal cancer patients. Human phospho-kinase array and pull-down assay results showed that quercetin-3-methyl ether (Q3ME) is a natural flavonoid compound that interacted with AKT and ERKs and inhibited their kinase activities. At the cellular level, Q3ME attenuated esophageal cancer cell proliferation and anchorage-independent growth. Western blot analysis showed that this compound suppressed the activation of AKT and ERKs downstream signaling pathways, subsequently inhibiting activating protein-1 (AP-1) activity. Importantly, Q3ME inhibited the formation of esophageal preneoplastic lesions induced by N-nitrosomethylbenzylamine (NMBA). The inhibition by Q3ME was associated with decreased inflammation and esophageal cancer cell proliferation in vivo. Collectively, our data suggest that Q3ME is a promising chemopreventive agent against esophageal carcinogenesis by targeting AKT and ERKs.

One of the main functions of the piwi-interacting RNA pathway is the post-transcriptional silencing of transposable elements in the germline of many species. In insects, proteins belonging to the Tudor superfamily proteins belonging to the Tudor superfamily play an important role in to play an important role in this mechanism. In this study, we identified the tudor gene in the oriental fruit fly, Bactrocera dorsalis, investigated the spatiotemporal expressional profile of the gene, and performed a functional analysis using RNA interference. We identified one transcript for a tudor homologue in the B. dorsalis transcriptome, which encodes a protein containing the typical 10 Tudor domains and an Adenosine triphosphate (ATP) synthase delta subunit signature. Phylogenetic analysis confirmed the identity of this transcript as a tudor homologue in this species. The expression profile indicated a much higher expression in the adult and pupal stages compared to the larval stages (up to a 60-fold increase), and that the gene was mostly expressed in the ovaries, Malpighian tubules and fat body. Finally, gene knockdown of tudor in B. dorsalis led to clearly underdeveloped ovaries in the female adult and reductions in copulation rate and amount of oviposition, indicating its important role in reproduction. The results of this study shed more light on the role of tudor in ovary development and reproduction.

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