In animal development, the maternal-to-zygotic transition (MZT) is an early universal transition characterized by two major events: activation of zygotic transcription and degradation of maternally provided mRNAs. On the latter one, the post-transcriptional control plays a major role to regulate maternally deposited mRNAs that cannot be regulated at the transcriptional level. The clearance of maternal mRNA depends in microRNAs (miRNAs) and RNA-binding proteins (RBPs). miRNAs are small RNA molecules that, like RBPs, regulate gene expression, causing mRNA decay and translational repression. Non-coding RNA and small peptides of 10-35 amino acids also play an active role in gene expression regulation. High-throughput sequencing of RNA fragments protected by RBP (Clip and Par-clip) or ribosome, followed by RNAse treatment, allow the identification of RBP-RNA interactions and the measurement of gene translation efficiency. Global translational data allowed us to define: a) Translated genes, b) Non-translated genes (probable Non-coding), c) Putative small peptides and d) Translated genes poorly annotated. Therefore, the aims of my research are: a) to build a high-resolution map of RBP-RNA interactions to unravel the function of RBP in MZT, and b) to perform a ribosome profiling to define non-coding, small peptides and translational regulation during MZT.