Current models of early development assign major roles to stochastic processes and epigenetic regulation, whose influence is considered to outweigh the genetic differences that exist between individuals. However, epigenetic agents are ultimately encoded by genes. It follows that the variable endowment of oocytes in these genes’ products could influence, prime or even predetermine developmental trajectories and features of embryos. As model system we used inbred strains of mice (129/Sv, C57Bl/6, C3H/HeN, DBA/2J). We examined if and in how far the composition of oocytes is conserved after we observed large variability in developmental competence and embryo quality across the four strains. Using state-of-the-art proteomics (SILAC LC-MS/MS) combined with transcriptomics (RNA deep sequencing) we quantified 2012 protein groups and 15205 transcripts present simultaneously in oocytes of all four strains. Proteome and transcriptome expression levels had little correlation with each other, whereby the endowment of oocytes in proteins with known or putative function in embryo development could not be predicted from mRNA abundance. Our data show that depending on the oocyte donor strain, resultant embryos have different qualities that correlate with the abundance of catalytic proteins, highlighting the importance of proteomic quantifications in modern embryology. Thus, different strains of mice should not be used interchangeably when tackling questions about oogenesis and early development, and a variety of strains should be studied to yield results of sufficient general validity.