Illumina HiSeq 4000 sequencing
Small RNA library preparation and sequencing was performed on an Illumina HiSeq 4000 at Fasteris SA (Plan-les-Ouates, Switzerland) using the Drosophila small RNA track based on the Illumina TruSeq protocol. Total RNAs from ovaries were size selected (18 to 30 nt) on denaturing PAGE. The small RNA fraction was then depleted from the 2S rRNA (30 nt) using a highly specific probe developed by Fasteris. 3' adapter sequence: TGGAATTCTCGGGTGCCAAG. Index: CAACTA