For small RNA-seq analysis of oocytes, at least 5 oocytes per animal were collected and incubated at 75°C for 3 min to release small RNAs. Small RNAs libraries were prepared using the NextFlex Small RNA-seq v3 kit (Amplicon) according to the manufacturer´s protocol with 3´ adapter ligation overnight at 16 °C, 25 cycles used for PCR amplification and gel purification used for size selection. For gel purification, libraries were separated on a 2,5% agarose gel using (1x) lithium borate (LB) buffer and visualized with ethidium bromide. The 140-170 bp fraction was cut off the gel and DNA was isolated using the MinElute Gel Extraction Kit (Qiagen). Final libraries were sequenced by 75 nt single-end reading using the Illumina NextSeq500/550 platform.