人类线粒体DNA异质性研究进展及在法医学中的应用

线粒体DNA(mtDNA)异质性的存在使其在法医学应用变得复杂。本文对mtDNA异质性形成的可能原因、异质性的分布和遗传特点、异质性的筛查和定量方法、异质性对法医学的影响以及异质性的研究和展望等方面进行综述,探讨异质性在法医学上的应用价值。     

中国5个民族mtDNA(CA)n重复的多态性

目的 探讨中国维族、汉族、黎族、瑶族、藏族mtDNA 514-523位置(CA)n重复遗传多态性。方法应用自行设计的引物对维族、汉族、黎族、瑶族各100名无关个体及42名藏族无关个体进行直接测序。结果 维族人群发现5种等位基因,黎族4种,瑶族3种,而汉族、藏族只观察到两种等位基因。结论 五个民族间mtDNA(CA)_n重复次数存在差异,与国外其他人群相比也有差异。     

中国裕固族mtDNA遗传多态性

<正> 本文作者对中国裕固族群体的mtDNA的遗传特点进行研究,旨在为法医鉴定提供基础数据。     

中国广西瑶族群体mtDNA多态性

<正> 为了解中国瑶族mtDNA多态性,本文作者对中国瑶族无关个体mtDNA进行调查,现报道如下。1 材料与方法 105例瑶族无关健康个体样本取自广西都安瑶族自治县,三代内无族外通婚。     

不同检材mtDNA检验结果的分析

<正> 1 案例资料 案例1 1999年2月,邹某(男,70岁)被刺致死。提取嫌疑人的黑色皮衣(已清洗处理)检验,仅在袖口里衬发现一处绿豆大小的可疑血迹。经种属检验为人血后,对其和死者血液进行mtDNA序列分     

Results of the 2003–2004 GEP-ISFG collaborative study on mitochondrial DNA: Focus on the mtDNA profile of a mixed semen-saliva stain

We report here a review of the seventh mitochondrial DNA (mtDNA) exercise undertaken by the Spanish and Portuguese working group (GEP) of the International Society for Forensic Genetics (ISFG) corresponding to the period 2003–2004. Five reference bloodstains from five donors (M1–M5), a mixed stain of saliva and semen (M6), and a hair sample (M7) were submitted to each participating laboratory for nuclear DNA (nDNA; autosomal STR and Y-STR) and mtDNA analysis. Laboratories were asked to investigate the contributors of samples M6 and M7 among the reference donors (M1–M5). A total of 34 laboratories reported total or partial mtDNA sequence data from both, the reference bloodstains (M1–M5) and the hair sample (M7) concluding a match between mtDNA profiles of M5 and M7. Autosomal STR and Y-STR profiling was the preferred strategy to investigate the contributors of the semen/saliva mixture (M6). Nuclear DNA profiles were consistent with a mixture of saliva from the donor (female) of M4 and semen from donor M5, being the semen (XY) profile the dominant component of the mixture. Strikingly, and in contradiction to the nuclear DNA analysis, mtDNA sequencing results yield a more simple result: only the saliva contribution (M4) was detected, either after preferential lysis or after complete DNA digestion. Some labs provided with several explanations for this finding and carried out additional experiments to explain this apparent contradictory result. The results pointed to the existence of different relative amounts of nuclear and mtDNAs in saliva and semen. We conclude that this circumstance could strongly influence the interpretation of the mtDNA evidence in unbalanced mixtures and in consequence lead to false exclusions. During the GEP-ISFG annual conference a validation study was planned to progress in the interpretation of mtDNA from different mixtures.     

粪便DNA提取及检验

目的　研究人类粪便DNA的提取和检验方法。方法　 8人份粪便样本 ,磁珠法提取DNA后 ,进行STR复合扩增和mtDNAHVI区测序分析。结果　用 2种方法提取的粪便DNA ,STR复合扩增检验均未获成功 ;方法1提取的粪便DNA有 6个样本、方法 2有 7个样本获得了清晰可读的mtDNAHVI区序列 ,并与唾液对照样本DNA的序列完全一致。结论　用本文建立的方法提取粪便DNA ,不适于STR分析 ,可通过mtDNA测序分析进行检验。     

人类线粒体DNA的异质型

研究中国人群中线粒体 D 环区不同组织间的差别,用 PCR-测序方法对53个无关个体的毛发与血液样本进行线粒体 DNA 高变区 HVⅠ进行测序分析,通过377测序仪检测,发现1例个体中血液与毛发样本线粒体 HV Ⅰ区15997～16401间存在序列差异。在16235碱基处,毛发样本表现为 T,血液样本为 C/T。结果显示中国人群同一个体不同组织存在线粒体序列差异。     

Analysis of Mitochondrial DNA from a Burned,Ninhydrin‐Treated Paper Towel

Contact‐based evidence is likely to have limited quantities of DNA and may yield mixed profiles due to preexisting or contaminating DNA. In a recent arson investigation, a paper towel was collected and used as circumstantial evidence. The paper towel was partially burned and was likely set on fire with flammable liquid. As part of the investigation, the paper towel was treated with ninhydrin to visualize fingerprint evidence. Initial DNA analysis of two swabs was negative for short tandem repeat (STR) markers and revealed a mixture of mitochondrial DNA (mtDNA). Analysis of 13 additional cuttings yielded four more mixed profiles, but also two samples with a common single‐source profile. The single‐source mtDNA profile matched that of the primary suspect in the case. Thus, even if initial mtDNA analysis yields a mixed profile, a sampling strategy involving multiple locations can improve the chance of obtaining valuable single‐source mtDNA profiles from compromised evidence in criminal casework.     

人类mtDNA控制区异质性

目的观察mtDNA的点突变异质性和长度异质性。方法运用直接测序法对50名无关个体及16名母系家族成员的血液、口腔上皮细胞、头发的mtDNAHVI、HVII区序列进行分析,并对20例HVI区直接测序失败的无关个体进行克隆后测序分析。结果同一个体的三种检材样本及16名母系家族成员的序列一致,未见异质性存在;同一个体的不同克隆的C延伸区的长度有差异,存在长度异质性。但同一个体的血液和头发具有相似的长度变异类型,即长度异质性在组织间无差异。结论mtDNA碱基序列具有同质性及稳定性,适用于法医学检案。