|SHI, MIN - Zhejiang University|
|DONG, SHUAI - Zhejiang University|
|LI, MING-TIAN - Zhejiang University|
|YANG, YAN-YAN - Zhejiang University|
|CHEN, XUE-XIN - Zhejiang University|
Submitted to: Scientific Reports
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/9/2015
Publication Date: 2/2/2015
Citation: Shi, M., Dong, S., Li, M., Yang, Y., Stanley, D.W., Chen, X. 2015. The endoparasitoid, Cotesia vestalis, regulates host physiology by reprogramming the neuropeptide transcriptional network. Scientific Reports. 5:8173.
Interpretive Summary: Application of classical insecticides has introduced severe problems in agricultural sustainability. The concept of biological control of insects is a potentially powerful alternative to classical insecticides. Biological control is based on the idea that direct application of insect-specific parasites can reduce pest insect populations and the economic damage due to pest insects. The problem, however, is the lack of detailed understanding of the mechanisms involved in the relationship between parasites and their pest insect hosts. One approach to improving the efficiency of parasites in biological control programs would be to understand how parasites influence the physiology of their hosts. In this paper we report that parasitoids alter expression of specific genes in their hosts. These new research results will be directly useful to scientists who are working to improve the efficacy of biological control methods. The ensuing improved biological control methods will benefit a wide range of agricultural producers by reducing use of classical insecticides and supporting the long-term sustainability of agriculture.
Technical Abstract: Endoparasitoids develop inside another insect; success depends on regulating host immunity and development by maternal factors injected into hosts during oviposition, including venom, polydnaviruses and teratocytes. Although prior results provide insights into parasitism-induced immunosuppression, little is known about parasitoid mechanisms responsible for influencing host development and behavior. We posed the hypothesis that parasitization impacts expression of genes encoding pro-neuropeptides and used larvae of the diamond back moth, Plutella xylostella and its larval endoparasitoid, Cotesia vestalis to test our hypothesis. We prepared transcriptomes from the larval P. xylostella brain-CC-CA complex and identified transcripts encoding19 neuropeptides. All corresponding cDNAs were confirmed by RACE. Results demonstrate that parasitism significantly down-regulated, or delayed, expression of genes encoding pro-neuropeptides within 48 h post-parasitization. Changing expression of these genes leads to the previously reported decreased feeding behavior, reduced growth rates and aborted development in the host larvae. In effect, parasitization operates at the molecular level within the CNS to create global changes in larval host biology. The significance of our finding is that, in addition to the known effects on immunity, parasitoids directly affect host pro-neuropeptide gene transcription to their own advantage. Operating on CNS gene expression may be a general mechanism in metazoan parasite/host relationships.