DNA甲基化作為法醫(yī)學組織標記的可行性研究
發(fā)布時間：2018-10-19 09:36
【摘要】：背景鑒別在犯罪現(xiàn)場發(fā)現(xiàn)的斑痕等人體檢材的組織來源,對判斷案件類型和證明犯罪事實有重要的作用。當代法庭科學對微量、陳舊生物證據的應用,使組織鑒別變得更為必要,同時在技術是也提出了更高的要求。探索新型的分子組織標記,研究開發(fā)與當代DNA分析技術相匹配的組織鑒別技術,是目前法醫(yī)物證學的研究熱點之一。 目的本研究調查人體主要組織膠質纖維酸性蛋白(Glial fibrillary acidic protein,GFAP)基因和DEAD盒多肽4(DEAD (Asp-Glu-Ala-Asp) box polypeptide 4,DDX4)基因的啟動子甲基化水平,評估GFAP啟動子低甲基化作為腦組織、DDX4啟動子低甲基化作為精液斑組織標記的可行性,初步探討DNA甲基化作為法醫(yī)組織標記的意義。 方法應用聯(lián)合亞硫酸氫鹽的限制酶法(Combined Bisulfite Restriction Analysis,COBRA),一種半定量的DNA甲基化檢測技術,調查6例尸體主要組織(大腦、心臟、肺、肝、胰、脾、腎、皮膚)和17例精液的GFAP和DDX4啟動子甲基化水平,對數(shù)據進行單因素方差分析并確定判別值。 結果人類大腦組織GFAP啟動子甲基化水平均低于45.82%((X|￣)_(brain)=44.70%,S_(brain)=8.38%),非腦組織均高于58.60%((X|￣)_(non-brain)=68.01%, S_(non-brain)=1.42%),以52.87%為判別值,可以有效的區(qū)別腦組織與非腦組織。人精液DDX4啟動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)) ,體細胞組織均高于75.41%((X|￣)_(somatic)=82.73%_(EcoRI), 82.94%_(TaqI);S_(somatic)=3.54%_(EcoRI), 3.91%_(TaqI)),以49.85%(EcoRI位點)或50.58%(TaqI位點)為判別值,可以有效的區(qū)別精液斑組織與非精液斑組織。 結論大腦組織的GFAP啟動子甲基化水平顯著低與非腦組織,精液DDX4啟動子甲基化水平顯著低與非精液的體細胞組織,GFAP啟動子低甲基化可作為腦組織特異標記,DDX4啟動子低甲基化可作為精液特異標記�？紤]到法醫(yī)學檢材的特殊性和DNA標記的優(yōu)勢,組織特異性甲基化變異位點(methylation-variable positions,MVPs)可能是一種理想的分子組織標記。篩選一組合適的組織特異性MVPs位點,開發(fā)通用的基于DNA甲基化的組織ID系統(tǒng),可能是解決目前法醫(yī)組織鑒定問題的有效途徑。
[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鉤鍧囦綆浜，
本文編號：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鉤鍧囦綆浜，
本文編號：2280753
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