Parasites and DNA extraction
Single tapeworms each of T. multiceps and T. pisiformis tapeworm were collected for DNA extraction and sequencing. T. multiceps was collected from a dog infected experimentally with Coenurus cerebralis from naturally infected sheep (Gansu Provincial Huangcheng Wool Sheep Breeding Farm). A single cysticercus of T. pisiformis was isolated from a naturally infected rabbit (at a slaughterhouse in Shandong Province) in our laboratory, and a cyst of the same species was collected from a rabbit in Henan Province. One T. hydatigena cyst was collected from the abdominal cavity of a sheep at a slaughterhouse in Qinghai Province. Other adult worms, T. asiatica, T. saginata and T. solium from patients were also used for genomic DNA extraction. Fragments from the tapeworms and a protoscolex from the cyst were washed with cold phosphate-buffered saline and frozen in liquid nitrogen. Genomic DNA was isolated using Genomic DNA Purification Kit (Puregene® DNA Purification System, Gentra Systems, Minneapolis, Minnesota, USA) according to the manufacturer's instructions.