Abstract: Shortened telomere length and mitochondrial DNA copy number changes are recognized as molecular markers of aging. In this study, quantitative PCR technology was used to detect the dynamic changes of telomere length and mitochondrial DNA copy number in 9 tissues of female and male C57BL/6 mice aged 2－24 months. A mouse aging evaluation model based on two molecular markers was constructed by multiple linear regression, and the fit degree (r²) of the regression model was between 0.4－0.8. Through this model, it was found that at least one molecular marker of senescence was significantly associated with the age of the month in 9 tissues of female or male mice. As a practical application, whether reproductive stress had an effect on female aging was analyzed using the constructed aging assessment model. Studies have found that reproduction accelerates the aging process of the female mice, mainly in peripheral blood, heart, cortical and spleen tissues. In this study, an aging evaluation model was constructed for 9 tissues, which could be used to evaluate the accelerated aging effect of various experimental interventions on 9 tissues of female or male C57BL/6 mice.

Key words: telomere length, mitochondrial DNA copy number, reproductive pressure, aging evaluation model, real-time PCR technology