Updated project metadata. We have identified eukaryotic translation initiation factor 4E family member 1B (Eif4e1b) as a regulator of maternal RNA translation, whose maternal deletion leads to 2-cell arrest phenotype in mouse embryos. eIF4E1b protein binds mRNA selectively in oocytes and controls their translation in early embryos. We aim to profile the global changes in protein expression in metaphase II (MII) eggs and zygotes collected from control or Eif4e1b knockout female mice. An encapsulated proteomic-sample processing protocol is used to perform this low-input mass spectrometry to quantify proteomic changes (Kulak et al. 2014/PMID 24497582).