2.1 Sample collection and genome sequencing
Fenneropenaeus chinensis shrimp were obtained from the conservation base of Haifeng Aquaculture Co., Ltd. (Weifang, Shandong Province, China). Muscle of a 7-months-old male shrimp was collected and frozen in liquid nitrogen immediately. Total genomic DNA was extracted and sequenced for genome survey and genome construction. Genome construction contains PacBio sequencing (Eid et al., 2009) and Hi-C assembly (Lieberman-Aiden et al., 2009). DNA sample used for genome survey and Hi-C assembly was sequenced by Illumina HiSeq platform (Illumina, San Diego, USA), and used for PacBio sequencing was sheared to 20 Kb and sequenced by PacBio Sequel platform (Pacific Biosciences, Menlo Park, USA).