We observed degradation ofβ‑actin mRNA and 18S rRNA in mouse spleen cells under constant temperature conditions in the different temperature group during postmortem intervals(PMIs)of 0-72 h.Thirty‑nine mice were sacr...We observed degradation ofβ‑actin mRNA and 18S rRNA in mouse spleen cells under constant temperature conditions in the different temperature group during postmortem intervals(PMIs)of 0-72 h.Thirty‑nine mice were sacrificed by cervical dislocation and kept at constant temperatures of 10℃,15℃,20℃,25℃,and 30℃.From 0 to 72 h after death,total RNA in spleen cells was extracted every 6 h.The cycle threshold(Ct)values ofβ‑actin mRNA and 18S rRNA were obtained by real‑time‑quantitative polymerase chain reaction.The results showed that,under the conditions of different and constant temperatures after mouse death at 72 h,the Ct values ofβ‑actin and 18S,Ct ratios ofβ‑actin to 18S,and relative ratios ofβ‑actin to 18S were significantly correlated with PMI.In addition,the relative degradation rates ofβ‑actin and 18S appeared to change from fast to slow with the increase of temperature.By interpolation and fitting analysis of the data,we obtained a ternary quintic equation of the relationship between the change in the relative ratios and PMI,which can be used to infer PMI within a certain temperature range(10℃-30℃).展开更多
基金This work was supported by the Open Project of Key Laboratory of Forensic Genetics,Ministry of Public Security(No.2017FGKFKT05)Beijing Natural Science Foundation(No.7192121)Chinese Academy of Engineering(No.2019‑XZ‑31).
文摘We observed degradation ofβ‑actin mRNA and 18S rRNA in mouse spleen cells under constant temperature conditions in the different temperature group during postmortem intervals(PMIs)of 0-72 h.Thirty‑nine mice were sacrificed by cervical dislocation and kept at constant temperatures of 10℃,15℃,20℃,25℃,and 30℃.From 0 to 72 h after death,total RNA in spleen cells was extracted every 6 h.The cycle threshold(Ct)values ofβ‑actin mRNA and 18S rRNA were obtained by real‑time‑quantitative polymerase chain reaction.The results showed that,under the conditions of different and constant temperatures after mouse death at 72 h,the Ct values ofβ‑actin and 18S,Ct ratios ofβ‑actin to 18S,and relative ratios ofβ‑actin to 18S were significantly correlated with PMI.In addition,the relative degradation rates ofβ‑actin and 18S appeared to change from fast to slow with the increase of temperature.By interpolation and fitting analysis of the data,we obtained a ternary quintic equation of the relationship between the change in the relative ratios and PMI,which can be used to infer PMI within a certain temperature range(10℃-30℃).
