Proteomic interactions between the parasitoid Diachasmimorpha longicaudata and the oriental fruit fly, Bactrocera dorsalis during host parasitism

Authors: Chang, Chiou; LIANG, GUANG HONG - Fuijan Agricultural University; Geib, Scott

Submitted to: Journal of Asia Pacific Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/7/2017
Publication Date: 12/7/2017
Citation: Chang, C.L., Liang, G., Geib, S.M. 2017. Proteomic interactions between the parasitoid Diachasmimorpha longicaudata and the oriental fruit fly, Bactrocera dorsalis during host parasitism. Journal of Asia Pacific Entomology. https://doi.org/10.1016/j.aspen.2017.12.002.
DOI: https://doi.org/10.1016/j.aspen.2017.12.002

Interpretive Summary: Oriental fruit flies are important agricultural pests worldwide and their larval parasitoid, Diachasmimorph longicaudata is one of their most effective biological control agents. How a parasitoid interacts with its host as an endo-parasitoid is very important while it is rarely studied at molecular level. The aim of this study is to identify the molecular interaction between host and parasitoid at the proteomic level during the process of host parasitism to synchronize with their biological interactions.

Technical Abstract: Background: Oriental fruit flies are important agricultural pests worldwide and their larval parasitoid, Diachasmimorph longicaudata is one of their most effective biological control agents. How a parasitoid interacts with its host as an endo-parasitoid is very important while it is rarely studied at molecular level. Methods: We compared proteome profile of fruit fly and parasitoid between parasitized and control/non-parasitized at different developmental time points using 2-D gel electorphoresis and mass spectroscopy. Proteins were identified using the Mascot search algorithm against a custom peptide database representing a collection of closely related host (Diptera) and parasitoid (Hymenoptera) proteomes derived from either publically available genomic or transcriptomic databases. Results: We identified 327 differentially expressed protein spots (109 proteins) between parasitized and control during parasitism. We also found that the molecular processes affected by parasitism varied at different time points during development. We discussed these protein changes at different time points as: transferrin and muscle specific protein 20 are the only two proteins differentially expressed 24h after parasitism that play a role in host immunity. Developmental and metabolic proteins from parasitoids (transferrin and enolase) were up-regulated to ensure establishment and early development of parasitoids 48h post parasitism. 72h after parasitism, larval cuticle proteins, transferrin and cellular repressor of E1A stimulated genes 1 (CREG1) were over expressed to support the survival of parasitoids while host metabolism proteins and parasitoid regulatory proteins were down-regulated. Host development slowed down while parasitoid development went up at 96h after parasitism. All development–related proteins were expressed at their extremes, either upregulated or downregulated at 120h post parasitism. Host development was reduced, with metabolism and regulatory proteins being strongly involved. Host development deteriorated further at 144h after parasitism. Enolase and CREG1 were indicators of parasitoid survival. Hexamerin and transferrin from the parasitoid peaked at 168-216h after parasitism, strongly indicating that parasitoid would survive. Conclusion: Parasitoid did not kill its host until it ensured its survival. This study represents the first report that reveals the molecular players involved in the interaction between the host and parasitoid.