ABSTRACT
Objective To investigate the genetic diversity and phylogenetic relationship of Sparganum isolates from snakes in Hunan Province. Methods The partial mitochondrial NADH dehydrogenase subunit 4 (pnad4) and NADH dehydrogenase subunit 5 (pnad5) genes were amplified using a PCR assay in 7 Sparganum isolates from snakes in Hunan Province and the amplification product was sequenced. The homology and genetic evolution were investigated using the software DNAMAN 7.0, MegAlign, DnaSP 5.0 and MEGA 5.0. Results The pnad4 and pnad5 gene sequences were approximately 578 bp and 484 bp in length in the 7 Sparganum isolates from Hunan Province, and the percentages of genetic variations were 0 to 2.8% and 0 to 0.8%, respectively. There were 4 haplotypes detected in both the pnad4 and pnad5 genes, with global haplotype diversities of 0.810 ± 0.016 and 0.905 ± 0.011, nucleotide diversities of 0.006 ± 0.005 and 0.004 ± 0.003, and mean nucleotide variations of 3.960 and 1.905, respectively. Phylogenetic analysis showed that all 7 Sparganum isolates from snakes in Hunan Province were clustered into the same branch with Spirometra erinaceieuropaei isolates from different regions/hosts in the world, which belonged to S. erinaceieuropaei, which were close to Diphyllobothrium latum and far from other tapeworms. Conclusion There is a low genetic variation in snake-derived S. erinaceieuropaei isolates from Hunan Province, and both pnad4 and pnad5 genes may be potential molecular genetic markers for identification of S. erinaceieuropaei.