Research Paper Volume 14, Issue 1 pp 143—160

Figure 1. Comparison of skeletal muscle transcriptomes of 2-, 24-, and 28-month-old mice. (A) Representative age ranges for mature life history stages in C57BL/6J mice are shown, together with human age equivalents: 10 to 14 months-of-age as middle age and 18 – 24 months as early phase of aging (E-aging) [10]. We added the life phase of 25 – 28 months or older as late phase of aging (L-aging); note that we substituted the “old” definition in the online article [10] with E-aging. We named 24 and 28 months-of-age as “young-old” and “old-old”. Aging phases are shaded in different colors. (B) Principal component analysis (PCA). Transcriptomes of different age groups are marked as dots and lines with different colors. 2m, 24m, and 28m stand for 2-, 24-, and 28-month-old mice, respectively. (C) Volcano plots for comparison of gene expression between 2m versus 28m (left), 2m versus 24m (middle), and 24m versus 28m (right). Differentially expressed genes (log₂ (fold change > 1.0 and p < 1 × 10^–5) are colored.