Research Paper Volume 11, Issue 1 pp 185—208

Rapamycin-mediated mTOR inhibition impairs silencing of sex chromosomes and the pachytene piRNA pathway in the mouse testis

Figure 5. Chronic rapamycin treatment affects the expression of mitochondrial and piRNA pathway genes. Samples were testis tissue (3 control, 3 rapamycin-treated males) and pachytene spermatocytes (pacSC) and round spermatids (rST) isolated from pooled samples (control, n=7 males; rapamycin, n=15). (a) Heatmap of differentially expressed genes. (b) Gene ontology analysis of genes that were downregulated in pachytene spermatocytes from rapamycin-treated mice versus control. (c) Quantitative RT-PCR analysis of piRNA pathway component transcripts in testis tissue. Error bars represent SD (*P < 0.05, Student’s t test). (d) Relative mRNA level of piRNA pathway genes in pachytene spermatocytes and round spermatid populations. Error bars represent SD (*P < 0.05, Student’s t test). (e, f) Western blot analysis of piRNA pathway associated proteins in testis (e), and isolated spermatocytes and round spermatids (f) from control (-) and rapamycin-treated (+) males. (g) Western blot analysis of OXPHOS subunits. β-Actin served as loading control. (h) Immunostaining of testis sections for MT-CO1 (green). Arrowheads mark accumulation of MT-CO1 at the periphery of nuclei in rapamycin-treated testis. Scale bar, 20μm.