Immune signaling pathways in the endoparasitoid, Pteromalus puparum

Authors: YANG, LEI - Zhejiang University; WANG, JIALE - Zhejiang University; JIN, HONGXIA - Zhejiang University; FANG, QI - Zhejiang University; YAN, ZHICHAO - Zhejiang University; LIN, ZHE - Zhejiang University; ZOU, ZHEN - Chinese Academy Of Sciences; SONG, QISHENG - University Of Missouri; Stanley, David; YE, GONGYIN - Zhejiang University

Submitted to: Archives of Insect Biochemistry and Physiology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/20/2019
Publication Date: 10/9/2019
Citation: Yang, L., Wang, J., Jin, H., Fang, Q., Yan, Z., Lin, Z., Zou, Z., Song, Q., Stanley, D.W., Ye, G. 2019. Immune signaling pathways in the endoparasitoid, Pteromalus puparum. Archives of Insect Biochemistry and Physiology. 103(2):e21629. https://doi.org/10.1002/arch.21629.
DOI: https://doi.org/10.1002/arch.21629

Interpretive Summary: Beneficial insect species provide valuable ecological services to humans. Many beneficials, such as honey bees, bumble bees, solitary bees, hoverfiies, butterflies, moths and flower beetles (in total, more than 20,000 insect species), are responsible for pollinating nearly 900 high-value food crops. Other beneficial insects are natural enemies of pest insect species. Parasitoid insects deposit their eggs into or onto other insect species, where larvae hatch from the eggs and develop to adulthood using the resources of their host insect. Many parasitoid species provide important biological control services by killing pest insects. Some parasitoid species are commercially raised and released to control pest insects. Despite their economic importance, there is very little genetic information on the beneficials. Such information is crucial to optimizing their use and economic value. This paper is one of a series of seven papers reporting on genomic analyses of the beneficial parasitoid, Pteromalus puparum. Here, we report on genes operating in immune signaling pathways. We identified 202 immune-related genes, which encode proteins that recognize infections, signal infections and operate in active immune reactions. This work will be used by scientists working on insect immunology and may benefit consumers generally.

Technical Abstract: Parasitoids provide multiple ecological services of high value to agricultural, including maintaining natural insect population balances and serving as effective biocontrol agents. Parasitoids develop from eggs to adults within or on their hosts and they have evolved very intimate co-evolutionary relationships involving host defense from parasitoids and neutralization of the defenses by parasitoids. It follows that insect immunity is a potent axis of host/parasitoid interactions. Parasitoids, like all insects, are also challenged by numerous microbial pathogens. Research in insect immunity has developed into a very large, highly competitive and fast-moving field. Yet, compared to the vast literature on insect immunology, little is known about the immune mechanisms of parasitoids, possibly due to their very small sizes. Here, we identified and characterized potential immune-related genes of the endoparasitoid, Pteromalus puparum, which act in regulating populations of some members of the Pieridae. We identified 202 immune-related genes based on interrogating the P. puparum genome and transcriptome databases. We categorized the cognate gene products into recognition molecules, signal moieties and effector proteins operating in four pathways, Toll, IMD, JAK/STAT and JNK. Comparative analyses of immune-related genes from seven insect species indicates that recognition molecules and effector proteins are more expanded and diversified than signaling genes in these signal pathways. There are common 1:1 orthologs between P. puparum and its relative, the pteromalid parasitoid Nasonia vitripennis. Our work provides comprehensive analyses of P. puparum immune genes, some of which may be exploited in advancing parasitoid-based biocontrol technologies.