The reduced sperm count observed in Ago2 cKO mice implies that AGO2 has non-redundant functions in the male germ line. Because AGO2 is a key protein in the RNA interference (RNAi) pathway, we first postulated that AGO2 loss disrupts normal transcriptional and translational dynamics of target mRNAs relevant to sperm maturation. To address this hypothesis, we took advantage of the apparently normal spermatogenesis in Ago2 cKO mice, which allowed us to purify matched meiotic and post-meiotic germ cells from Ago2 cKO and wild type controls. We examined changes in the transcriptome and proteome of these two spermatogenic stages in Ago2 cKO relative to control mice using RNA-seq and quantitative mass spectrometry (MS). To further examine if the changes in mRNA and protein levels detected in Ago2 cKO germ cells was due to a loss of regulation by the canonical AGO2-miRNA pathway, we characterized AGO2 protein interactors by AGO2 immunoprecipitation-mass spectrometry (IP-MS) in cytoplasmic and nuclear fractions of post-meiotic cells