design: Juvenile or adult fish aged between 1-1.5 years were euthanized in 400ppm MS-222. The gonads were dissected into cold 1 X PBS, and thoroughly cleared of associated fat or viscera, then collected into Trizol and homogenized using a hand-held pellet pestle, and stored at 80C. Total RNA was extracted using Zymo Research Direct-zol RNA MicroPrep with DNAse treatment. LunaScript RT Supermix kit with 1g of RNA was used to synthesize cDNA. Diluted cDNA samples (50ng/L) were used for sequencing.