Project description:We wished to investigate if adaptation to host-plant diet is the basis of differentiation for two strains of Spodoptera frugiperda (Lepidoptera:Noctuidae). We performed reciprocal transplant experiments in laboratory conditions, feeding each strain (sf-C and sf-R) with artificial diet, corn plants or rice plants. RNA-Seq was performed on pooled 4th instar larvae from this experiment. We compared this transcriptional response with that of individual 4th instar larvae collected in corn and grass fields in Florida.
Project description:Insect gut microbiota plays important roles in acquiring nutrition, preventing pathogens infection, immune responses, and communicating with the environment. Gut microbiota can be affected by some external factors such as foods, temperature, and antibiotics. Spodoptera frugiperda (Lepidoptera: Noctuidae) is an important destructive pest of grain crops all over the world. The function of gut microbiota in S. frugiperda remains to be investigated. In this study, we fed the S. frugiperda with the antibiotic mixture (penicillin, gentamicin, rifampicin, and streptomycin) to perturb the gut microbiota, and further examined the effect of dysbiosis in gut microbiota on the gene expression of S. frugiperda by RNA sequencing. We found the composition and diversity of the gut bacterial community were changed in S. frugiperda after antibiotics treatmen, and the expression of genes related to energy and metabolic process were affected after antibiotics exposure in S. frugiperda. Our work will help understand the role of gut microbiota in insects.
Project description:Purpose: We analyzed the 3rd-instar Spodoptera frugiperda response after SfAV-1a infection. Specifically, we targeted three gene types in the infected host namely, mitochondrial, cytoskeleton and innate immunity genes.
Project description:Comparison of the effects of 2 polydnaviruses (HdIV vs MdBV) injection on L5 Spodoptera frugiperda larvae hemocytes transcriptome. The experimental design is as follows: 3 biological replicates with dye swap. Each treatment (HdIV or MdBv) is compared to control treatment (PBS).
Project description:Nematodes such as Steinernema carpocapsae are used as organic pesticides because of their ability to prey on live insects. They do so thanks to their symbiotic bacteria, that they release within the hemocoel of insects. In this study we wanted to study how Spodoptera frugiperda, a Lepidoptera pest of crops becoming invasive around the world, defend themselves against the nematodes. We infested S. frugiperda larvae with nematodes and dissected three tissues: the midgut, the fat body and the hemocytes at two time-points: 8 h and 15 h after infestation. We performed single-end RNA-seq on these samples to study the tissue specificity of S. fru response, as well as its dynamic.
Project description:Spodoptera frugiperda is the world’s major agricultural pests, and has the distinctive features of high fecundity, strong migratory capacity and high resistance to most insecticides. At present, the control of S. frugiperda in China relies mainly on the spraying of chemical insecticides. MicroRNAs (miRNAs) are a class of small, single-stranded, non-coding RNAs, and play crucial regulatory roles in various physiological processes, including the insecticide resistance in insects. However, little is known about the regulatory roles of miRNAs on the resistance of S. frugiperda to insecticides. In the present research, the miRNAs that were differentially expressed after cyantraniliprole, spinetoram, emamectin benzoate and tetraniliprole treatment were analyzed by RNA-Seq. A total of 504 miRNAs were systematically identified from S. frugiperda, and 24, 22, 31 and 30 miRNAs were differentially expressed after treatments of cyantraniliprole, spinetoram, emamectin benzoate and tetraniliprole. GO and KEGG enrichment analyses were used to predict the function of differentially expressed miRNAs’ target genes. Importantly, ten miRNAs were significantly differentially expressed among the treatments of three insecticides. MiR-278-5p, miR-13b-3p, miR-10485-5p and miR-10483-5p were significantly down-regulated among the treatments of three insecticides by RT-qPCR. Furthermore, overexpression of miR-278-5p, miR-13b-3p, miR-10485-5p and miR-10483-5p significantly increased the mortality of S. frugiperda to cyantraniliprole and emamectin benzoate. The mortality was significantly increased with spinetoram treatment after overexpression of miR-13b-3p, miR-10485-5p and miR-10483-5p. These results suggest that miRNAs, which are differentially expressed in response to insecticides, may play a key regulatory role in the insecticide resistance in S. frugiperda.
