Abstract:Genetic variation and phylogenetic relationship of Trichinella isolates from China
LIU Li-na, CUI Jing, JIANG Peng, WANG Lei, LI Ling-zhao, ZHANG Xi, WANG Zhong-quan
(Department of Parasitology, Medical College, Zhengzhou University, Zhengzhou 450052, China)
ABSTRACT: Genetic variation and phylogenetic relationship of Trichinella isolates from China were studied by analysis of the mitochondrial cytochrome coxidase gene (COI) and mitochondrial small subunit ribosomal DNA (mtSSU) as molecular markers. The DNA fragments from the 7 Trichinella isolates from China were amplified by PCR-based methods. The genetic distances and sequence similarity were compared with the corresponding sequences of T. spiralis in GenBank by using the DNAMAN software. The phylogenetic trees were constructed by MEGA 4.0 with Neighbor-joining method. The results showed that the DNA fragments with 649bp(mtSSU)and 419bp(COΙ) from the 7 isolates were amplified, and some different with that of T. spiralis in GenBank. The mtSSU gene had four variable sites (248, 293, 537, and 539), COI gene had only two variable site (273 and 382), and all the type of genetic variations were conversion of C-T or T-C. Based on the phylogenetic tree, Nanyang and Yunnan isolates were close, while the phylogenetic relationship of Tibet, Xi’an and Guangxi isolates were closer. The results demonstrated that the genetic variation of the 7 T. spiralis isolates from China was small and their phylogenetic relationship was close.