Figure 4.

Levels of modifications in tRNA during a time range of 24 h discriminated by the original and newly-synthesized tRNA pool. *The quantity of modification was normalized to its respective origin (e.g., new m⁷G was normalized to abundance of new tRNA to receive the number of m⁷G per new tRNA while original m⁷G was normalized to original tRNA). a Level of 7-methylguanosine (m⁷G) in new and original tRNAs over time. The constant level of original m⁷G is caused by a constant increase in pre-existing m⁷G, while post-methylated m⁷G increases (box). (error bars reflect the SE of n = 6) b 2′-O-methylcytidine (Cm) increases fast in newly synthesized tRNAs, while the level of pre-existing Cm drops (box). This drop is masked by substantial post-methylation of original tRNAs. (error bars reflect the SE of n = 6) c Pseudouridine quantities are lower in newly-synthesized tRNAs while d the number of inosine per respective tRNA is constant throughout the experiment (both n = 3)