PCR-SSCP OF RDNA FOR THE IDENTIFICATION OF TRICHINELLA ISOLATES FROM MAINLAND CHINA

A polymerase chain reaction (PCR)-based single strand conformation pol ymorphism (SSCP) analysis of the expansion segment 5 (domain IV) of th e large subunit of ribosomal DNA was employed to characterize seven is olates of Trichinella from China (A-G), including six of pig origin fr om regions in Dengxian (A), Tianjin (B), Harbin (D), Baoshan (E), Xiny e (F) and Xian (G), and one of canine origin from Changchun (C). Isola tes A, D, E, F and G were classified as Trichinella spiralis based on SSCP patterns, while the patterns for isolates B and C were consistent with those of Trichinella nativa or Trichinella T6. The results were supported by random amplified polymorphic DNA (RAPD) analysis using fi ve decamer primers and were in accordance with ecological information for the isolates. Single strand conformation polymorphism results also allowed the direct display of mutational sequence variation in the ex pansion segment among the five isolates of T. spiralis from China, ind icating its usefulness for studying population variation within that s pecies. (C) 1998 Academic Press Limited.