Figure 2.

Downregulation of unc‐120 expression induces precocious appearance of muscle aging markers. (a–b) Relative quantity of transcripts measured in 7‐day‐old animals fed either control or (a) unc‐120 or (b) hlh‐1 RNAi bacteria. For each gene, results were normalized to their respective control. Bars are mean ± SEM (n = 6), Mann–Whitney test. (c–d) Relative quantity of (c) unc‐120 or (d) hlh‐1 transcripts in wild‐type young adults (YA) and 7‐day‐old animals. For each gene, results were normalized to the respective YA stage values. Bars are mean ± SEM (n = 6), Mann–Whitney test. (e) Quantification of animals with the indicated muscle mitochondria phenotypes, at days 2, 6, and 9 of adulthood animals expressing a mitochondria‐targeted GFP in muscle cells (see Experimental procedures section), fed control or unc‐120 RNAi bacteria. n = 52, 57, and 54 for control worms and n = 58, 63, and 70 for unc‐120 RNAi‐treated worms at days 2, 6, and 9, respectively. Data are presented as mean ± SEM, chi‐square test. (f) Number of autophagic vesicles per muscle cell at different days of adulthood in animals expressing a GFP marker of autophagic vesicles in body‐wall muscles (see Experimental procedures section), fed control or unc‐120 RNAi bacteria. Number of animals scored: n = 40, 48, 63, and 41 for control worms; n = 44, 50, 50, and 10 for unc‐120 RNAi‐treated worms at days 2, 7, 10, and 12, respectively. Bars are mean ± SEM, Kruskal–Wallis and Dunn's post hoc test. (g) Body bend frequency at different adult ages of animals fed control or unc‐120 RNAi bacteria. n = 37, 131, 92, and 66 for control worms and n = 34, 126, 94, and 70 for unc‐120 RNAi‐treated animals at YA, days 3, 7, and 10, respectively. Bars are mean ± SEM, Kruskal–Wallis and Dunn's post hoc test. (h) Survival curves of worms fed control or unc‐120 RNAi bacteria. The corresponding average lifespans were 16.9 ± 0.4 days (n = 137) and 14.1 ± 0.3 days (n = 121) for control and unc‐120 RNAi conditions, respectively