DNA甲基化作为法医学组织标记的可行性研究
发布时间：2018-10-19 09:36
【摘要】：背景鉴别在犯罪现场发现的斑痕等人体检材的组织来源,对判断案件类型和证明犯罪事实有重要的作用。当代法庭科学对微量、陈旧生物证据的应用,使组织鉴别变得更为必要,同时在技术是也提出了更高的要求。探索新型的分子组织标记,研究开发与当代DNA分析技术相匹配的组织鉴别技术,是目前法医物证学的研究热点之一。 目的本研究调查人体主要组织胶质纤维酸性蛋白(Glial fibrillary acidic protein,GFAP)基因和DEAD盒多肽4(DEAD (Asp-Glu-Ala-Asp) box polypeptide 4,DDX4)基因的启动子甲基化水平,评估GFAP启动子低甲基化作为脑组织、DDX4启动子低甲基化作为精液斑组织标记的可行性,初步探讨DNA甲基化作为法医组织标记的意义。 方法应用联合亚硫酸氢盐的限制酶法(Combined Bisulfite Restriction Analysis,COBRA),一种半定量的DNA甲基化检测技术,调查6例尸体主要组织(大脑、心脏、肺、肝、胰、脾、肾、皮肤)和17例精液的GFAP和DDX4启动子甲基化水平,对数据进行单因素方差分析并确定判别值。 结果人类大脑组织GFAP启动子甲基化水平均低于45.82%((X|￣)_(brain)=44.70%,S_(brain)=8.38%),非脑组织均高于58.60%((X|￣)_(non-brain)=68.01%, S_(non-brain)=1.42%),以52.87%为判别值,可以有效的区别脑组织与非脑组织。人精液DDX4启动子甲基化水平均低于50.41 % ((X|￣)sperm=11.52%_(EcoRI), 11.88%_(TaqI) ; S_(sperm)=8.98%_(EcoRI), 10.25%_(TaqI)) ,体细胞组织均高于75.41%((X|￣)_(somatic)=82.73%_(EcoRI), 82.94%_(TaqI);S_(somatic)=3.54%_(EcoRI), 3.91%_(TaqI)),以49.85%(EcoRI位点)或50.58%(TaqI位点)为判别值,可以有效的区别精液斑组织与非精液斑组织。 结论大脑组织的GFAP启动子甲基化水平显著低与非脑组织,精液DDX4启动子甲基化水平显著低与非精液的体细胞组织,GFAP启动子低甲基化可作为脑组织特异标记,DDX4启动子低甲基化可作为精液特异标记。考虑到法医学检材的特殊性和DNA标记的优势,组织特异性甲基化变异位点(methylation-variable positions,MVPs)可能是一种理想的分子组织标记。筛选一组合适的组织特异性MVPs位点,开发通用的基于DNA甲基化的组织ID系统,可能是解决目前法医组织鉴定问题的有效途径。
[Abstract]:Background Identification of the origin of the physical examination materials found at the crime scene plays an important role in judging the type of case and proving the fact of the crime. The application of modern forensic science to trace and obsolete biological evidence makes tissue identification more necessary and requires higher technical requirements. To explore new molecular tissue markers and to develop tissue identification techniques matching modern DNA analysis techniques is one of the hot topics in forensic forensics. Objective to investigate the promoter methylation of glial fibrillary acidic protein (Glial fibrillary acidic protein,GFAP) gene and DEAD cassette polypeptide 4 (DEAD (Asp-Glu-Ala-Asp) box polypeptide 4 (DDX4) gene in human tissues. To evaluate the feasibility of GFAP promoter hypomethylation as brain tissue and DDX4 promoter hypomethylation as seminal plaque tissue marker, and to explore the significance of DNA methylation as forensic tissue marker. Methods A semi-quantitative DNA methylation assay was used to detect DNA methylation in 6 cadaveric tissues (brain, heart, lung, liver, pancreas, spleen, kidney). The methylation levels of GFAP and DDX4 promoters in 17 semen samples were analyzed by univariate ANOVA and the discriminant values were determined. Results the methylation level of GFAP promoter in human brain tissue was lower than 45.82% (X (X) _ (brain) = 44.70Sm _ (brain) = 8.38%), non-brain tissue was higher than 58.60% (X (brain) _ (non-brain) = 68.01, Snon-brain = 1.42%), and 52.87% was the discriminant value, which could effectively distinguish brain tissue from non-brain tissue. 浜虹簿娑睤DX4鍚姩瀛愮敳鍩哄寲姘村钩鍧囦綆浜，
本文编号：2280753
[Abstract]:Background Identification of the origin of the physical examination materials found at the crime scene plays an important role in judging the type of case and proving the fact of the crime. The application of modern forensic science to trace and obsolete biological evidence makes tissue identification more necessary and requires higher technical requirements. To explore new molecular tissue markers and to develop tissue identification techniques matching modern DNA analysis techniques is one of the hot topics in forensic forensics. Objective to investigate the promoter methylation of glial fibrillary acidic protein (Glial fibrillary acidic protein,GFAP) gene and DEAD cassette polypeptide 4 (DEAD (Asp-Glu-Ala-Asp) box polypeptide 4 (DDX4) gene in human tissues. To evaluate the feasibility of GFAP promoter hypomethylation as brain tissue and DDX4 promoter hypomethylation as seminal plaque tissue marker, and to explore the significance of DNA methylation as forensic tissue marker. Methods A semi-quantitative DNA methylation assay was used to detect DNA methylation in 6 cadaveric tissues (brain, heart, lung, liver, pancreas, spleen, kidney). The methylation levels of GFAP and DDX4 promoters in 17 semen samples were analyzed by univariate ANOVA and the discriminant values were determined. Results the methylation level of GFAP promoter in human brain tissue was lower than 45.82% (X (X) _ (brain) = 44.70Sm _ (brain) = 8.38%), non-brain tissue was higher than 58.60% (X (brain) _ (non-brain) = 68.01, Snon-brain = 1.42%), and 52.87% was the discriminant value, which could effectively distinguish brain tissue from non-brain tissue. 浜虹簿娑睤DX4鍚姩瀛愮敳鍩哄寲姘村钩鍧囦綆浜，
本文编号：2280753
本文链接：https://www.wllwen.com/falvlunwen/fanzuizhian/2280753.html
