2.2 | Nucleic acid isolation, library construction and sequencing
We firstly removed the intestines of adult individuals under an inverted microscope to prevent intestinal microorganism contamination. Then, total genomic DNA was isolated from them using a sodium-dodecyl sulphate/proteinase K digestion(Gasser et al., 2006) followed by phenol-chloroform extraction and ethanol precipitation. For PacBio sequencing, 20-Kb SMRTbell libraries were constructed using the SMRTbell Template Prep Kit 1.0 (Pacific Biosciences, USA) and the SMRTbell Damage Repair Kit (Pacific Biosciences), according to the manufacturer’ s instructions. The Pacbio sequencing was performed with 1 SMRT cell on the PacBio SMRTplatform. For genome resequencing, 100-bp pair-end libraries were constructed and sequenced a whole genome sequence (WGS) short reads on DNBSEQ-T1 platform. For RNA-seq, RNA was isolated separately from an adult female and a male individual ofB. schroederi using TRlzol reagent (Invitrogen, USA) according to the manufacturer’s instructions and RNA yields were estimated spectrophotometrically (NanoDrop 1000), and integrity was verified using a Bioanalyzer. A total of 22Gb raw fastq data of female and 27 Gb raw fastq data of male were obtained. All transcripts were used to assess the completeness of the genome assembly and assist genome annotation.