2.3 DNA extraction, Library construction and sequencing
DNA was extracted from available blocks with the TIANamp Micro DNA Kit
(DP316, Tiangen Biotech) following the manufacturer’s protocol. We
constructed DNA libraries according to the standard protocol through
end-repaired adapter added overnight, and by applying polymerase chain
reaction amplification to the extracted DNA. To measure the adapters
before sequencing, quality control was carried out using a bioanalyzer
(Agilent 2100, Agilent Technologies, Santa Clara, CA, USA) combined
with quantitative PCR. DNA sequencing was then performed with the
BGISEQ-100 platform.