大鼠死后视网膜细胞mRNA降解与死亡时间的关系研究

目的检测死后大鼠视网膜细胞mRNA的降解和死亡时间(PM I)的关系,为死亡时间推断提供新方法。方法应用复合荧光RT-PCR技术,检测死后不同时间(2、4、6、8、10、12、14、16、18、20、22、24、26、28h)大鼠视网膜细胞β-actin、Pgk1和Rp l 4 mRNA水平,以立即处死大鼠作为对照。方差检验比较组间差异,并对所得数据进行回归分析。结果死后28h内,大鼠视网膜细胞β-actin、Pgk1、Rp l 4 mRNA水平均随死亡时间的延长而下降。3个管家基因mRNA的降解与死亡时间的线性拟合回归方程分别为:Yβ-actin=-4436.205Xβ-actin+127581.7(r2=0.976),YPgk1=-1993.884XPgk1+57651.54(r2=0.973),YRp l 4=-1189.791XRp l 4+34533.46(r2=0.955)。结论大鼠死后视网膜细胞mRNA的含量随着死亡时间的延长而逐渐降解,与死亡时间具有相关性。

The relationship between mRNA degradation in retina and PMI of rat after death

Objective To study the relationship between the mRNA degradation in the retinal cells of rat after death and postmortem interval(PMI) in order to provide a new methods of inferring PMI.Methods The level of β-actin,Pgk1 and Rpl 4 mRNA in the retinal cell of rat were measured at different time(0,2,4,6,8,10, 12,14,16,18,20,22,24,26,28h)after death by compound fluorescence RT-PCR.The rats executed immediately were used as controls.Results Within 28h after death,the absorbance value of total RNA and the level of β-actin,Pgk1 and Rpl 4 mRNA in the retinal cells decreased along with the prolongation of PMI.The equations of linear regression fitting the relationship between mRNA degradation and PMI were as follows:Yβ-actin=-4436.205Xβ-actin+127581.7(r2=0.976),Ypgk1=-1993.884Xpgk1+57651.54(r2=0.973),YRpl 4=-1189.791XRpl 4+34533.46(r2=0.955).The return model had remarkable statistical significance(P<0.001).Conclusion The mRNA in the retinal cells after rat death degrade gradually along with the prolongation of PMI and has correlation with PMI.