title: RNA-seq of A. japonicus_muscle_collected in June_1
design: The total RNA was extracted from muscle tissues of every sea cucumber individual using the Trizol Kit (Invitrogen, USA) according to the manufacturers instructions. RNA degradation and contamination was monitored on 1% agarose gels. The mRNA was purified from the total RNA and cut into fragments using the TruSeq RNA Sample Prep Kit (Illumina). Qualified RNA samples were prepared to build cDNA libraries. First strand cDNA was synthesized using random hexamer primer and M-MuLV Reverse Transcriptase. Second strand cDNA synthesis was subsequently performed using DNA Polymerase I and RNase H. After adenylation of 3 ends of DNA fragments, NEBNext Adaptor with hairpin loop structure were ligated to prepare for hybridization. After purification with AMPureXP beads, the ligated products with about 250-300 bp were amplified to generate high quality cDNA libraries, which were then sequenced.