title: transcriptomic analysis of XX fugu gonad
design: After total RNA was extracted by Trizol reagent kit (Invitrogen, Carlsbad, CA,USA), the RNA  molecules in a size range of 1830nt were enriched by polyacrylamide gelelectrophoresis(PAGE). Then the 3 adapters were added and the 36-48nt RNAs were enriched. The 5 adapters were then ligated to the RNAs as well. The ligation products were reverse transcribed by PCR amplification and the 140-160bp size PCR products were enriched to generate a cDNA library and sequenced using Illumina HiSeq Xten by Gene Denovo  Biotechnology Co. (Guangzhou, China).