主题:【转帖】用sj TRECS,T细胞基因重组产物分析法测量杀手年龄————刑侦新思路

浏览0 回复0 电梯直达
省部重点实验室
结帖率:
100%
关注:0 |粉丝:0
新手级: 新兵
New 'CSI style' crime blood test 'could help police pinpoint suspect's age'

http://www.telegraph.co.uk/science/8153033/New-CSI-style-crime-blood-test-could-help-police-pinpoint-suspects-age.html?sms_ss=facebook&at_xt=4cee72c48b4bb884%2C0

By Andrew Hough 7:30AM GMT 23 Nov 2010

Using current DNA techniques, researchers found they could narrow a person’s age to within nine years.

Experts said the new test, which can work on dried bloodstains that are several years old, could lead to a major breakthrough for crime scene investigators and offer new hope to “cold cases”.

Existing methods rely on teeth, bones or other body parts to establish the age of a suspect.

But scientists at Erasmus University Medical Centre in Rotterdam, the Netherlands have used a characteristic of immune cells, known as T cells which recognise foreign invaders, to calculate an age.

Their study, reported online in the journal Current Biology, says their test provides better results than previous attempts to pinpoint ages through DNA testing.

“We have demonstrated that human age can be estimated from blood with reasonable accuracy using a simple, robust, and sensitive test assay,” said Dr Manfred Kayser, who led the study.

“Our method is applicable in situations where only bloodstains are available, which covers a large proportion of crime cases.

“I wouldn't be surprised if it could be used on historical blood stains that are decades or 100s of years old.”

T cells contain tiny loops of DNA known as “single joint TCR excision circles” or sj TRECS for short.

The scientists said the number of these loops of DNA declines at a constant rate with age.

Dr Kayser said the number of these molecules in a blood sample is counted against a reference gene not affected by age, which allows them to calculate the total amount of DNA in the sample.

"You have a problem because normally your DNA does not change with age," said Dr Kayser.

"What does change is the activity of certain genes over a lifetime, but that is at the RNA level, and crime labs aren't ready for that. So we really had to look for another approach."

The test estimates an age with an error range of approximately nine years.

The study also suggests that the test would be accurate in placing suspects into generational categories spanning over two decades.

Mark Jobling, a geneticist at the University of Leicester told Nature that the "correlation is pretty impressive".

"How useful it will be in practice as a forensic tool remains to be seen, although there will certainly be forensic cases where it will help as an investigative tool," he added.

我的评
1
sj TRECS, single joint TCR excision circles TRECs在等位基因上完全切除,并在外周组织中的T细胞中稳定存在,它不参与细胞染色体DNA的复制,并随着细胞分裂被逐代稀释。自从Douek研究小组通过此法发现TRECs水平随年龄增长呈递减趋势,这个分子用于胸腺依赖的T细胞发育分化的研究热点。特别是当人们发现感染HIV病毒的患者,TRECs水平即迅速下降。让人们意识到,胸腺在成人的免疫发育中可能起相当重要的免疫重建相关的作用_____尽管具体的机制还不明确。
2
这个消息看到我的第一反应是,9年的误差率,这个有任何意义么?那难道我要对一个实际犯罪年龄24岁的杀手,检测出一个疑犯13岁到33岁的结果?前后就是其他影响因素分析,比如,一个胸腺切除的患者/犯人?一个血干细胞移植的犯人?一个艾滋病的犯人(实际中非常常见)?
3
不过是个好思路,免疫分子的影响因素太多而不好控制,那么,端粒酶长度怎么样?

Now you got it.15,

补充阅读
T细胞基因重组产物分析法
TCR基因表达为占绝大多数的αβTCR和占一小部分的γδTCR。位点δ位于α基因座,在Vα和Jα之间,TCRA和TCRB基因在重排中产生被切除DN***段的游离环,即T细胞受体基因重组环(TCR-rearrangement excision circles,TRECs)。TRECs在等位基因上完全切除,并在外周组织中的T细胞中稳定存在,它不参与细胞染色体DNA的复制,并随着细胞分裂被逐代稀释。因此,TRECS水平可以反映胸腺内TCR基因的重组活性以及胸腺外T细胞的增殖效率。TCR重排的多样性必将伴随TRECs的多样性。但在所有有功能的αβTCR基因重排中,必须发生TCRA座位中TCRD的切除,分别产生信号连结TREC——sjTREC(signal-joint TREC)和编码连结TREC——cjTREC(coding-joint TREC),可作为初生T细胞的普遍标记

T细胞受体基因重组环(TCR-rearrangement excision circles,TRECs)。TRECs在等位基因上完全切除,并在外周组织中的T细胞中稳定存在,它不参与细胞染色体DNA的复制,并随着细胞分裂被逐代稀释。因此,TRECS水平可以反映胸腺内TCR基因的重组活性以及胸腺外T细胞的增殖效率。TCR重排的多样性必将伴随TRECs的多样性。但在所有有功能的αβTCR基因重排中,必须发生TCRA座位中TCRD的切除,分别产生信号连结TREC——sjTREC(signal-joint TREC)和编码连结TREC——cjTREC(coding-joint TREC),可作为初生T细胞的普遍标记。

resource
http://www.telegraph.co.uk/science/8153033/New-CSI-style-crime-blood-test-could-help-police-pinpoint-suspects-age.html?sms_ss=facebook&at_xt=4cee72c48b4bb884%2C0
By Andrew Hough 7:30AM GMT 23 Nov 2010

reference
退休的胸腺:有关T细胞发生的研究
王卉, 朱乃硕 (上海复旦大学 生命科学学院,上海 200433)
该帖子作者被版主 dong36262积分, 2经验,加分理由:谢谢分享
为您推荐
您可能想找: 气相色谱仪(GC) 询底价
专属顾问快速对接
立即提交
可能感兴趣
猜你喜欢最新推荐热门推荐更多推荐
品牌合作伙伴