2.2 Sample collection and preparation
A healthy male M. japonicus from the off-shore area by Fujian Takifugu Breeding Station (Zhangzhou, Fujian, China) was selected to sequence and assemble the genome. A standard phenol/chloroform protocol (Sambrook et al., 1989) was used to extract high-quality genomic DNA (gDNA) from muscle tissue. Agarose gel electrophoresis and Qubit 2.0 Fluorimeter (Life Technologies, Carlsbad, CA, USA), were used to check the quality and quantity of the extracted DNA, respectively. Transcriptomic samples from seven tissues, including eyestalk, gills, hepatopancreas, hemocytes, intestines, muscle, and stomach, were collected for cDNA library preparation. Total RNA was extracted using the TRIzol Reagent (Invitrogen, Waltham, MA, USA) according to the manufacturer’s instructions and the quality of RNA was checked using an Agilent 2100 Bioanalyzer (Agilent Technologies, Santa Clara, CA, USA).