Small RNA-Seq of goat endometrium: sample 1 of day 16 of pregnancy
Total RNA was extracted using Trizol reagent (Invitrogen, Carlsbad, CA, USA) following the manufacturers instruction. RNA degradation and contamination were monitored on 1% agarose gels. RNA purity was checked using the NanoPhotometer spectrophotometer (IMPLEN, CA, USA) at 260 and 280 nm, and RNA integrity was assessed using the RNA Nano 6000 Assay Kit of the Agilent Bioanalyzer 2100 system (Agilent Technologies, CA, USA). Approximately 3 g of total RNA were used as input material for the small RNA library according to the protocol of NEBNext Multiplex Small RNA Library Prep Set for Illumina (NEB, USA). C16 library was constructed by mixing the three samples with equal concentration, performing the single-end sequencing (50 bp) on an Illumina Hiseq 2500 platform (Illumina, SanDiego, USA) according to the manufacturers recommended protocol, and P16 library was constructed in the same way as the C16 library.