基于嗜尸性蝇类离食期及蛹期分子信息进行PMI推断的研究

死亡时间（PMI）推断是法医学实践难点和研究热点。法医昆虫学在PMI推断应用中具有独特优势，现有PMI推断体系的构建主要基于嗜尸性蝇类非成虫期的形态学变化特征，而占该阶段约50%的离食期、蛹期仍缺乏形态学判断标准，严重阻碍蝇类证据在法庭科学中的应用。深入研究离食期及蛹期生长发育相关分子信息的时序性规律，是完善现有体系的关键突破点。本项目拟在前期棕尾别麻蝇全基因组测序基础上，选择与离食期、蛹期发育相关的表皮蛋白、几丁质酶及酪氨酸羟化酶等调控基因，揭示其与形态变化的内在联系，探究其差异表达的时序性规律。同时采用UPLC–MS/MS探究具有发育时间推测潜力的代谢产物，结合CDs传感器阵列构建高灵敏检测系统；随后，基于物理学FTIR验证发育过程中分子信息的时序变化规律，构建多维回归方程。最终全面挖掘该物种具有应用于PMI推断价值的分子信息，为解决蝇类证据在法庭科学中的应用提供理论依据。

Forensic entomology plays a major role in the postmortem interval (PMI) estimation, which is recognized as one of the pillars of forensic medicine and where dipteral flies are particularly valued. The existing PMI estimation system is mainly based on morphological changes in the developmental period, while the absence of morphological judgment criteria in the wandering and pupal stages, which account for about 50% of the non-adult stage, seriously hinders the application of fly evidence in forensic science. The breakthrough to perfect the existing system, as we have found, is to research the rule of the molecular information related to growth and development changing with time during the wandering and pupal stage. In this study, based on the De novo genome assembly of Sarcophaga peregrina (Diptera: Sarcophagidae), we would use RNA-Seq, RNAi and qRT-PCR technologies to screen genes related to growth and development, and exploring the rule of differential expression genes changing with time during development on the basis of defining their specific functions. Meanwhile, we carry out a metabonomic analysis by UPLC-MS/MS to explore the metabolites with potential of estimation developmental time, and construct a highly sensitive detection system with the combination of CDs sensor array. Then，we will verify the rule of timing changes of these molecular information by the physical FTIR and construct multidimensional regression equations. Ultimately, we will comprehensively reveal the molecular information of the species related to PMI estimation and provide theoretical basis involving the application of fly evidence in forensic science.