Transcription-Wide Mapping of Dihydrouridine (D) Reveals that mRNA Dihydrouridylation is Essential for Meiotic Chromosome Segregation

Epitranscriptomic has emerged as a fundamental control of gene expression. Nevertheless, the determination of the transcriptome-wide occupancy of RNA modifications remains challenging. We have developed Rho-seq, an integrated pipeline detecting a range of modifications through differential modification-dependent Rhodamine labeling. Using Rho-seq, we confirm that the reduction of uridine to dihydrouridine targets tRNAs in E. coli. Unexpectedly, we find that the D modification expands to mRNAs in fission yeast.The modified mRNAs are enriched for cytoskeleton-related encoding proteins. We show that the α-tubulin encoding mRNA nda2 undergoes dihydrouridylation, which affects its protein expression level. The absence of the modification onto the nda2 mRNA  impacts meiosis by inducing a metaphase delay or by completely preventing the formation of spindles during meiosis I and meiosis II, resulting in low gamete viability. Collectively these data show that the codon-specific reduction of uridine within specific mRNA is required for proper meiotic chromosome segregation and gamete viability.