Adult wildtype mouse testis
MIWI RNA Immunoprecipitation (RIP)  assays were performed with standard RIP protocols. In brief, mouse round spermatids  were homogenized in lysis buffer [50 mM Tris-HCl (pH 7.4), 150 mM NaCl, 1% Triton X-100, 5 mM EDTA, 1 x Complete Mini, RNase inhibitor(Thermo) and proteinase Inhibitor cocktail (Roche)]. Primary antibody-coupled Protein A/G beads were added to the precleared tissue  and incubated for 4 hr at 4 C. After washed with washing buffer [50 mM Tris-HCl (pH 7.4), 500 mM NaCl, 0.1% Triton X-100, 5 mM EDTA, RNase inhibitor(Thermo) and proteinase inhibitor cocktail]. RNA libraries were prepared for sequencing using NEBNext Multiplex Small RNA Library Prep Set for Illumina protocols. Size selection for 10-50nt RNAs.