Epitranscriptomic regulation and genome stability of the fertilized egg and the preimplantation embryo.

Pseudouridine (Ψ) dynamics in the preimplantation embvryoPseudouridine (Ψ) is the most abundant post-transcriptional modification and is widespread in most RNA species. Several techniques have been developed to map this modification: Ψ-seq, Pseudo-seq, PSI-seq, CeU-seq, RBS-seq and BID-seq (Zhang, Dai, & He, 2023)Pseudouridine (Ψ) is condisered a key post-transcriptional modification in RNA, yet mapping of Ψ typically requires large amounts of input material. The lowest starting amount reported to date is 10 ng of polyA+ RNA using the BID-seq technique, which is still too much for mapping the Ψ in oocytes and embryos. The lowest starting amount reported to date is 10 ng of polyA+ RNA using the BID-seq technique, which is still too much for mapping the Ψ in oocytes and embryos. Recently, a sensitive picogram-scale MeRIP-seq (picoMeRIP-seq) method for m6A was demonstrated (Y. Li et al., 2024). During my postdoc period, I propose to use the picoMeRIP-seq methods to landscape the Ψ in mouse oocytes and preimplantation embryos. An overarching goal is to understand the role of Ψ during embryonic development in different species. In 2024 we have established a protocol for mapping of Pseudouridine in mRNA and other RNA-species. We are currently collecting oocytes and embryos to study the dynamics of Pseudouridine in the very early stage of life. Since such dynamics could also be key for cancerous growth, we also aim at obtaining funding for studying the role of Pseudouridine in cancer.