Estimating time of death based on the biological clock
Estimating time of death based on the biological clock
复制标题
DOI：
10.1007/s00414-010-0527-4
复制
发表时间：
2011-05-01
影响因子：
2.1
通讯作者：
Kondo, Toshikazu
中科院分区：
文献类型：
--
作者：
Kimura, Akihiko;Ishida, Yuko;Kondo, Toshikazu
生物钟可能会在身体死亡时停止。因此，生物钟似乎对估计死亡时间很有用。在这项研究中，我们试图读取身体组织中的生物钟，以使用分子生物学技术来估计死亡时间。首先，我们对小鼠肾脏、肝脏和心脏中mPer2和mBMal1的基因表达进行了实时RT-PCR分析，这两个基因构成了振荡系统中的反馈环。即使在死后48小时，我们也能在小鼠组织中检测到这些基因表达的昼夜振荡。因此，mPer2/mBMal1的比值被发现可用于估计死亡时间。接下来，我们将这种方法应用于死后间隔不到72小时的法医尸检案例中获得的肝脏、肾脏和心脏。在这些尸检样本中可以检测到hPer2/hBMal1比值的显著昼夜波动。我们进一步研究了hRev-Erbα的基因表达，这是另一个反馈环的一个组成部分。HRev-Erbα/hBMal1的比值比hPer2/hBMal1的振荡幅度更大，更适合于死亡时间的估计。特别是，hRev/hBMal1比率为50表明死亡时间为0200-0900小时，hRev/hBMal1比率大大超过75表明死亡时间为0200-0800小时。另一方面，hRev/hBMal1低于25的比率强烈表明死亡时间为1000-2300小时。综上所述，这些发现表明，对生物钟的基因表达分析可能是估计死亡时间的有力方法。
The biological clock may stop at the time of death in a dead body. Therefore, the biological clock seems useful for estimating the time of death. In this study, we tried to read the biological clock in tissues from dead bodies to estimate the time of death using molecular biological techniques. At first, we examined real-time RT-PCR analysis of gene expression for mPer2 and mBmal1, which constitutes a feedback loop in the oscillation system, in the kidney, liver, and heart of mice. We could detect circadian oscillation of these gene expressions in mouse tissues even at < 48 h after death. Thus, the ratio of mPer2/mBmal1 was found to be useful for estimating the time of death. We next applied this method to the liver, kidney, and heart obtained from forensic autopsy cases with less than 72 h of postmortem interval. Significant circadian oscillation of hPer2/hBmal1 ratio could be detected in these autopsy samples. We further examined gene expression for hRev-Erb alpha, a component of another feedback loop. The ratios of hRev-Erb alpha/hBmal1 showed higher amplitude of oscillation than those of hPer2/hBmal1 and are considered more suitable for estimating the time of death. In particular, a hRev/hBmal1 ratio of > 50 indicated the time of death as 0200-0900 hours, and a hRev/hBmal1 ratio that considerably exceeded 75 indicated the time of death as 0200-0800 hours. On the other hand, a hRev/hBmal1 ratio of less than 25 strongly indicated the time of death as 1000-2300 hours. Taken together, these findings indicate that gene expression analyses of the biological clock could be powerful methods for estimation of the time of death.