Transcription-wide distribution of dihydrouridine (D) into mRNAs reveals its requirement for meiotic chromosome segregation. [Rho-Seq]

Here we have developed Rho-seq, an integrated pipeline detecting a range of modifications through differential modification-dependent Rhodamine labeling. Using Rho-seq, we report that the reduction of uridine to dihydrouridine by the Dus reductase family targets tRNAs in E. coli but expands to mRNAs is yeast. The modified mRNAs are enriched for cytoskeleton related encoded protein. We show that the a-tubulin encoding mRNA nda2 undergoes dihydrouridination, which affects its protein expression level. The absence of the modification onto the nda2 mRNA strongly impacts meiosis by inducing a metaphase delay or by completely preventing the formation of spindles during meiosis I and meiosis II, eventually resulting in low gamete viability. Collectively these data show that the codon specific reduction of uridine within mRNA is required for proper meiotic chromosome segregation and gamete viability. Overall design: Rho-seq in wild-type and strains were all genes encoding for dus enzymes are deleted in S.pombe and E.coli, in control condition (named noR or R-) or conditions where a chemical treatment makes the presence of dihydrouridine on RNA cause RT drop off during RNA-seq library preparation (a condition named R or R+).