基于外周血circRNA标记的法医物证学年龄推断研究

Age estimation is an important part of forensic DNA phenotyping, as well as an important standard of determining the nature of the case and sentencing of the parties. Hence, it is important to accurately estimate the age of an individual in forensic routine work. At present, there are still some limits in forensic age estimation such as the application scope and inference accuracy. Developing new inference methods and exploring new inference markers will help to expand the application scope of forensic age estimation as well as improve the accuracy. Blood is a common sample in forensic routine work. It is helpful to case investigation by accurately and efficiently estimating the age of relevant person through blood samples left in the crime scene. The circRNA marker is closely related to aging and is more stable than linear RNA. It is suitable for aged and degraded samples. The technology of simultaneous RNA and DNA isolation makes it possible to detect circRNA without affecting the conventional DNA individual identification. This project intends to use human peripheral blood samples to find circRNA closely related to human age by circRNA sequencing; followed by validation with quantitative real-time PCR to screen and evaluate candidate circRNAs for individual age estimation. The selected circRNAs are then used to establish a statistical inference model. The determined circRNAs and relative inference model are then validated. The project would provide new ideas for forensic age estimation.

年龄推断是法医学表型推断的重要组成部分，还具有决定案件性质和当事人量刑的功能，准确推断个体年龄对法医学实践具有重要意义。目前的年龄推断方法在适用范围、推断精度等方面仍存在不足，开发新的推断方式，探索新的推断标记，有助于扩大法医学年龄推断的适用范围，提高推断准确度。血液是法医物证学实践中常见的检材，准确、高效的通过案发现场遗留的血液检材推断相关人员年龄，有利于案件的侦破。circRNA标记与衰老密切相关，稳定性优于线性RNA，适用于陈旧、降解检材，通过DNA和RNA共提取技术，可以在不影响常规DNA个体识别鉴定的同时进行检测。本项目拟利用人类外周血样本，通过circRNA测序发现与人类个体年龄密切相关的circRNA，结合实时定量PCR验证，筛选适用于年龄推断的标记，并进行评估，选择与年龄相关性最好的circRNA，建立统计学推断模型，评估该模型精确度，为法医物证学个体年龄推断提供新的思路。

随着分子生物学技术的发展，法医个体识别正在经历从“被动识别”到“主动识别”的过程。.法医学表型推断涉及到的体貌特征主要包括面部容貌、色素特征、身高、年龄等。其中，个体的年龄不仅会影响包括面部容貌、发色、体态等多种体貌特征，还是决定案件性质和当事人是否需要承担刑事责任的重要标准。目前现有的年龄推断方式还存在一定的不足，有必要探索开发新的推断标记和推断方法，对现有的法医年龄推断方式进行补充和完善，使年龄推断的结果更加准确、可靠。.本课题利用人类外周血全血样本，通过 circRNA 测序，筛选与人类个体年龄密切相关的 circRNA 候选位点，并拟通过实时定量 PCR进一步验证获得的 circRNA 候选位点，利用受试者工作特征曲线评估候选位点与人类个体年龄的相关性，选择与人类个体年龄相关性最好的 circRNA 位点，建立统计学推断模型，评估该模型在进行人类个体年龄推断时的标准误差，为法医物证学个体年龄推断补充新的候选标志物。.研究对全血circRNA进行提取富集后进行测序，初筛得到6067个circRNA，进一步筛选获得3409个高可信度circRNA。计算高可信度circRNA的表达量，并在不同年龄组间进行差异分析，最终筛选出11个差异位点。基于差异位点设计合成Q-PCR引物，进行扩增验证后，11个位点中的7个扩增较为正常，适合用于进一步分析。.个体年龄推断是法医学表型推断的重要组成部分，还具有决定案件性质和当事人量刑的功能，如果能够准确、高效的通过案发现场常见的血液检材推断相关人员年龄，将有利于案件的侦破工作。circRNA 标记与衰老密切相关，稳定性优于线性RNA，适用于陈旧、降解检材，通过DNA和RNA共提取技术，可以在不影响常规DNA个体识别鉴定的同时进行检测。探索外周血circRNA标记与年龄的相关性，建立基于外周血circRNA标记的人类个体年龄推断方法，对于优化法医物证学个体年龄推断方式具有积极意义。