以蔬菜害虫菜青虫蛹期优势寄生蜂蝶蛹金小蜂的PpSerpin-1基因为研究对象，在前期初步明确其基因结构及表达模式的基础上，我们推测PpSerpin-1基因通过可变剪接产生功能多样性，部分可变剪接体在母蜂毒液和幼虫唾液中进化出寄主调控功能。据此，本项目拟采用qRT-PCR、Western Blot、原核/真核蛋白表达纯化、Pull-down、进化树构建和正选择分析等技术手段，对PpSerpin-1基因各可变剪接体的转录表达模式、生理功能、互作靶标和进化关系展开系统研究。最终，探明PpSerpin-1基因可变剪接体的功能多样性，解析寄生蜂通过可变剪接招募寄生因子蛋白的潜在机制，揭示寄生蜂-寄主的互作机理，丰富寄生蜂基因的进化模式，为今后寄生蜂基因的利用和改造提供理论依据和技术保障。

Pteromalus puparum is a pupal endoparasitoid wasp that parasitizes a number of butterflies including the agricultural pest small cabbage white butterfly, Pieris rapae. Using this parasitoid wasp as research model, our previous study identified 16 alternative splicing isoforms in P. puparum Serpin-1 (PpSerpin-1) gene. One of these isoforms was found in venom with host immunosuppression function. From transcriptomic data, these 16 isoforms were demonstrated with diverse expression patterns across different tissues and developmental stages. Some isoforms significantly and differentially express in larval salivary gland...Based on these lines of evidence, we hypothesize here that PpSerpin-1 isoforms get functional diversity through alternative splicing, and some isoforms in venom and larval saliva even evolve functions for host regulation. To test this hypothesis, systematic analysis will be conducted in this project to investigate their transcription and expression patterns, biological functions, targets and evolutionary relations of these alternative splicing isoforms, using approaches like qRT-PCR, Western Blot, prokaryotic/eukaryotic protein expression and purification, Pull-down, phylogenetic construction and positive selection analysis. ..Finally, expected results will elucidate functional diversity of PpSerpin-1 isoforms, reveal how parasitoids recruit virulent genes through alternative splicing. Knowledges from this project will provide better understanding of parasitoid-host interaction mechanism, enrich evolutionary theory of parasitoid wasps’ genes, also supply both theoretical basis and technical supporting for modifying and using parasitoid genes in pest control in the future.