Molecular characterization of Ephestia kuehniella (Lepidoptera: Pyralidae) transferrin and its response to parasitoid Venturia canescens (Hymenoptera: Ichneumonidae Gravenhorst)

Cellular Redox-Related Transcription Factor Nrf2 Mediation of HaTrf Response to Host Plant Allelochemical 2-Tridecanone in Helicoverpa armigera

Despite there being a number of excellent studies on detoxification enzyme-mediated interaction between insect and plant allelochemical, there are no reports on the pathway of the transferrin effect in insect response to host plant allelochemical. Our research indicates that Helicoverpa armigera transferrin (HaTrf) inhibited the apoptotic cell death treated by 2-tridecanone, a host plant allelochemical present in tomato species (Lycopersicon hirsutum f. glabratum), by cellular redox-related transcription factor nuclear factor erythroid-2-related factor 2 (Nrf2). Nrf2 can defend organisms against the detrimental effects of oxidative stress and play pivotal roles in preventing host plant allelochemical-related toxicity. This study explains how HaTrf inhibited the apoptotic cell death during exposure to host plant allelochemical 2-tridecanone and provides a novel view on transferrin and its anti-apoptotic role in plant-insect interactions.

Comparative Genomics of Glossina palpalis gambiensis and G. morsitans morsitans to Reveal Gene Orthologs Involved in Infection by Trypanosoma brucei gambiense

Blood-feeding Glossina palpalis gambiense (Gpg) fly transmits the single-celled eukaryotic parasite Trypanosoma brucei gambiense (Tbg), the second Glossina fly African trypanosome pair being Glossina morsitans/T.brucei rhodesiense. Whatever the T. brucei subspecies, whereas the onset of their developmental program in the zoo-anthropophilic blood feeding flies does unfold in the fly midgut, its completion is taking place in the fly salivary gland where does emerge a low size metacyclic trypomastigote population displaying features that account for its establishment in mammals-human individuals included. Considering that the two Glossina—T. brucei pairs introduced above share similarity with respect to the developmental program of this African parasite, we were curious to map on the Glossina morsitans morsitans (Gmm), the Differentially Expressed Genes (DEGs) we listed in a previous study. Briefly, using the gut samples collected at days 3, 10, and 20 from Gpg that were fed or not at day 0 on Tbg—hosting mice, these DGE lists were obtained from RNA seq—based approaches. Here, post the mapping on the quality controlled DEGs on the Gmm genome, the identified ortholog genes were further annotated, the resulting datasets being compared. Around 50% of the Gpg DEGs were shown to have orthologs in the Gmm genome. Under one of the three Glossina midgut sampling conditions, the number of DEGs was even higher when mapping on the Gmm genome than initially recorded. Many Gmm genes annotated as “Hypothetical” were mapped and annotated on many distinct databases allowing some of them to be properly identified. We identify Glossina fly candidate genes encoding (a) a broad panel of proteases as well as (b) chitin—binding proteins, (c) antimicrobial peptide production—Pro3 protein, transferrin, mucin, atttacin, cecropin, etc—to further select in functional studies, the objectives being to probe and validated fly genome manipulation that prevents the onset of the developmental program of one or the other T. brucei spp. stumpy form sampled by one of the other bloodfeeding Glossina subspecies.

A transferrin gene associated with development and 2-tridecanone tolerance in Helicoverpa armigera

The full-length cDNA (2320 bp) encoding a putative iron-binding transferrin protein from Helicoverpa armigera was cloned and named HaTrf. The putative HaTrf sequence included 670 amino acids with a molecular mass of approximately 76 kDa. Quantitative PCR results demonstrated that the transcriptional level of HaTrf was significantly higher in the sixth instar and pupa stages as compared with other developmental stages. HaTrf transcripts were more abundant in fat bodies and in the epidermis than in malpighian tubules. Compared with the control, the expression of HaTrf increased dramatically 24 h after treatment with 2-tridecanone. Apparent growth inhibition with a dramatic body weight decrease was observed in larvae fed with HaTrf double-stranded RNA (dsRNA), as compared with those fed with green fluorescent protein dsRNA. RNA interference of HaTrf also significantly increased the susceptibility of larvae to 2-tridecanone. These results indicate the possible involvement of HaTrf in tolerance to plant secondary chemicals.

De novo cloning and annotation of genes associated with immunity, detoxification and energy metabolism from the fat body of the oriental fruit fly, Bactrocera dorsalis

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.