Transcriptional responses of Daphnis nerii larval midgut to oral infection by Daphnis nerii cypovirus-23

Abstract

Background Daphnis nerii cypovirus-23 (DnCPV-23) is a new type of cypovirus and has a lethal effect on the oleander hawk moth, Daphnis nerii which feeds on leave of Oleander and Catharanthus et al. After DnCPV-23 infection, the change of Daphnis nerii responses has not been reported. Methods To better understand the pathogenic mechanism of DnCPV-23 infection, 3rd-instar Daphnis nerii larvae were orally infected with DnCPV-23 occlusion bodies and the transcriptional responses of the Daphnis nerii midgut were analyzed 72 h post-infection using RNA-seq. Results The results showed that 1979 differentially expressed Daphnis nerii transcripts in the infected midgut had been identified. KEGG analysis showed that protein digestion and absorption, Toll and Imd signaling pathway were down-regulated. Based on the result, we speculated that food digestion and absorption in insect midgut might be impaired after virus infection. In addition, the down-regulation of the immune response may make D. nerii more susceptible to bacterial infections. Glycerophospholipid metabolism and xenobiotics metabolism were up-regulated. These two types of pathways may affect the viral replication and xenobiotic detoxification of insect, respectively. Conclusion These results may facilitate a better understanding of the changes in Daphnis nerii metabolism during cypovirus infection and serve as a basis for future research on the molecular mechanism of DnCPV-23 invasion.

Post-feeding transcriptomics reveals essential genes expressed in the midgut of the desert locust

“…Based on our data, as well as reports in literature, multiple transcripts encoding putative digestive enzymes, nutrient transporters and other digestion-related genes are abundantly upregulated upon feeding ( Sanders et al, 2003 ; Xu et al, 2012 ; Cui and Franz, 2020 ). By contrast, immunity-related genes and detoxification enzymes are strongly upregulated upon infection or exposure to xenobiotics, respectively, while digestion-related genes are downregulated, although these reactions are often complex ( Noland et al, 2013 ; Herde and Howe, 2014 ; Dhania et al, 2019 ; Coutinho-Abreu et al, 2020 ; Kuang et al, 2021 ; Shu et al, 2021 ; Jin et al, 2022 ).…”

“…Annotated midgut transcriptomes have become abundantly available, though mostly in holometabolan insect orders, such as Diptera, Lepidoptera and Coleoptera, presumably due to their large species diversity and prevalence of insect pests in these orders ( Sanders et al, 2003 ; Campbell et al, 2005 ; Pauchet et al, 2009 ; Ma et al, 2012 ; Xu et al, 2012 ; Noland et al, 2013 ; Herde and Howe, 2014 ; Spit et al, 2016a ; Zhang et al, 2016 ; Gazara et al, 2017 ; Huang et al, 2017 ; Nadeau et al, 2017 ; Lu et al, 2018 ; Dhania et al, 2019 ; Bonelli et al, 2020 ; Coutinho-Abreu et al, 2020 ; Cui and Franz, 2020 ; Hung et al, 2020 ; Kuang et al, 2021 ; Shu et al, 2021 ; Zou et al, 2021 ; Hixson et al, 2022 ; Jin et al, 2022 ). As expected in the insect midgut, transcripts encoding digestive enzymes, nutrient transporters, and proteins involved in detoxification and peritrophic membrane formation are abundantly present ( Pauchet et al, 2009 ; Ma et al, 2012 ; Gazara et al, 2017 ).…”

“…Changes in immunity- and detoxification-related genes upon infection tend to be complex as well as species- and pathogen- or toxin-dependent. Upon infection, a shift in gene expression generally occurs, inhibiting digestive processes in favor of the immune system ( Noland et al, 2013 ; Coutinho-Abreu et al, 2020 ; Kuang et al, 2021 ). Transcriptomic studies investigating the xenobiotic metabolism in the digestive tract clearly revealed a strong ability of insects to metabolize foodborne toxins, i.e., plant-derived xenobiotics, bacterial entomotoxins, or synthetic insecticides ( Herde and Howe, 2014 ; Dhania et al, 2019 ; Shu et al, 2021 ; Jin et al, 2022 ).…”

The Phosphoserine Phosphatase Alters the Free Amino Acid Compositions and Fecundity in Cyrtorhinus lividipennis Reuter

“…After DnCPV-23 infection, the expression levels of the phosphoserine phosphatase genes were significantly higher in the DnCPV-23-infected midgut than in the non-infected group, suggesting that serine metabolism disorders were induced after DnCPV-23 infection [ 33 ]. Genetic mutants of astray (aay), a fly homolog of the rate-limiting phosphoserine phosphatase in serine biosynthesis, displayed reduced starvation-induced sleep suppression [ 34 ]. The larvae of B. mori were capable of synthesizing L -serine de novo via bmPSP with two other enzymes in the phosphorylated pathway [ 31 ].…”