Journal Article

The genomic features of parasitism, Polyembryony and immune evasion in the endoparasitic wasp Macrocentrus cingulum

Yin, Chuanlin, Song, Zhenkun, Hu, Jian, Guo, Dianhao, He, Kang, Zhang, Wenqing, Lang, Kun, Li, Meizhen, Dong, Yipei, Chen, Qiming, Chen, Xuexin, Liu, Jinding, Li, Fei, Luo, Jiapeng, Walters, James R.

2018

Overview

Background Parasitoid wasps are well-known natural enemies of major agricultural pests and arthropod borne diseases. The parasitoid wasp Macrocentrus cingulum (Hymenoptera: Braconidae) has been widely used to control the notorious insect pests Ostrinia furnacalis (Asian Corn Borer) and O. nubilalis (European corn borer). One striking phenomenon exhibited by M. cingulum is polyembryony, the formation of multiple genetically identical offspring from a single zygote. Moreover, M. cingulum employs a passive parasitic strategy by preventing the host’s immune system from recognizing the embryo as a foreign body. Thus, the embryos evade the host’s immune system and are not encapsulated by host hemocytes. Unfortunately, the mechanism of both polyembryony and immune evasion remains largely unknown. Results We report the genome of the parasitoid wasp M. cingulum . Comparative genomics analysis of M. cingulum and other 11 insects were conducted, finding some gene families with apparent expansion or contraction which might be linked to the parasitic behaviors or polyembryony of M. cingulum . Moreover, we present the evidence that the microRNA miR-14b regulates the polyembryonic development of M. cingulum by targeting the c-Myc Promoter-binding Protein 1 ( MBP-1 ), histone-lysine N-methyltransferase 2E ( KMT2E ) and segmentation protein Runt . In addition, Hemomucin, an O-glycosylated transmembrane protein, protects the endoparasitoid wasp larvae from being encapsulated by host hemocytes. Motif and domain analysis showed that only the hemomucin in two endoparasitoids, M. cingulum and Venturia canescens, possessing the ability of passive immune evasion has intact mucin domain and similar O-glycosylation patterns, indicating that the hemomucin is a key factor modulating the immune evasion. Conclusions The microRNA miR-14b participates in the regulation of polyembryonic development, and the O-glycosylation of the mucin domain in the hemomucin confers the passive immune evasion in this wasp. These key findings provide new insights into the polyembryony and immune evasion.

• Publisher: BioMed Central,BioMed Central Ltd,Springer Nature B.V,BMC
• Subject: Analysis / Animal Genetics and Genomics / Animals / Bioinformatics / Biomedical and Life Sciences / c-Myc protein / Cingulum / Comparative genomics / Contraction / Control / Corn / Eggs / Embryo, Nonmammalian - embryology / Embryos / Encapsulation / Endoparasites / Gene families / Genes / Genetic aspects / Genetic engineering / Genome / Genomes / Genomics / Glycosylation / Hemocytes / Histone-lysine N-methyltransferase / Host-Parasite Interactions - genetics / Host-Parasite Interactions - immunology / Hymenoptera / Immune evasion / Immune Evasion - genetics / Immune response / Immune system / Insects / Larvae / Life Sciences / Lysine / Macrocentrus cingulum / Methyltransferase / Microarrays / Microbial Genetics and Genomics / MicroRNAs / miRNA / Molecular Sequence Annotation / Mucin / Multicellular invertebrate genomics / Myc protein / Mycetophila cingulum / N-Methyltransferase / Natural enemies / Offspring / Ostrinia furnacalis / Parasitic diseases / Parasitism / Parasitoids / Pests / Phylogenetics / Phylogeny / Physiological aspects / Plant Genetics and Genomics / Polyembryony / Proteins / Proteomics / Research Article / Ribonucleic acid / RNA / Segmentation / Target recognition / Wasps / Wasps - embryology / Wasps - genetics