Abstract: Objective To explore the homogeneity level of four different functional mRNA （PUM2, TAB2, Cx45 and CHRNA1） expressions in rats with skeletal muscle contusion. Methods The relative expressions of PUM2, TAB2, Cx45 and CHRNA1 mRNAs were detected by quantitative real-time reverse transcription-polymerase chain reaction （RT-qPCR）. The coefficient of variation （CV） of the relative expressions for different individuals in each injury group was calculated. The extreme value of CV, cumulative variability, and CVCV were compared. Results A high CV of PUM2 and TAB2 mRNAs appeared on several different time points. However, the CV of Cx45 and CHRNA1 mRNAs was relatively low. The cumulative variability from high to low was PUM2, CHRNA1, TAB2 and Cx45 mRNAs. The relative expression of PUM2 mRNA was significantly higher than that of TAB2, Cx45 and CHRNA1 mRNAs （P<0.05）. There was no statistical significance （P>0.05） in the CVCV of the relative expression of TAB2, CHRNA1 and Cx45 mRNAs. Conclusion As the mRNAs involving in biological process regulation, PUM2 and CHRNA1 mRNAs show a lowest individual homogeneity of the relative expression followed by TAB2 mRNA. As the mRNAs participating in the composition of cellular structure, Cx45 and CHRNA1 mRNAs show a high individual homogeneity of the relative expressions. The functional classification should be considered for the screening of the mRNA indicators used for wound age estimation.

Key words: forensic pathology, wounds and injuries, RNA, messenger, muscle, skeletal, wound age estimation, homogeneity, rats