2.2 DNA extraction and sequencing
High-quality genomic DNA was extracted from blood samples using a modified CTAB (Hexadecyl Trimethyl Ammonium Bromide) method. The quality and quantity of the extracted DNA were examined using a NanoDrop 2000 spectrophotometer (NanoDrop Technologies, Wilmington, DE, USA), Qubit ds DNA HS Assay Kit on a Qubit 3.0 Fluorometer (Life Technologies, Carlsbad, CA, USA), and electrophoresis on a 0.8% agarose gel.
A paired-end sequencing library with an insertion length of 250 bp was constructed using the VAHTS Universal DNA Library Prep Kit for MGI (Vazyme, Nanjing, China). The Agilent 2100 Bioanalyzer (Agilent Technologies, Santa Clara, CA) was used to validated the purity and size distribution. Then, the obtained library was sequenced with the paired-end, 150-bp mode using the MGI-SEQ2000 platform by Frasergen Bioinformatics Co., Ltd. (Wuhan, China).
Ten micrograms (ug) of C. sonnerati genomic DNA were used for 20 kb template library preparation using the BluePippin Size Selection system (Sage Science, USA) following the manufacturer’s protocol. The library was sequenced on the Pacfic Biosciences Sequel II platform.