Mitochondrial Genome of Spirometra theileri Compared with Other Spirometra Species

Abstract

This study was carried out to provide information on the taxonomic classification and analysis of mitochondrial genomes of <i>Spirometra theileri</i>. One strobila of <i>S. theileri</i> was collected from the intestine of an African leopard (<i>Panthera pardus</i>) in the Maswa Game Reserve, Tanzania. The complete mtDNA sequence of <i>S. theileri</i> was 13,685 bp encoding 36 genes including 12 protein genes, 22 tRNAs and 2 rRNAs with absence of <i>atp</i>8. Divergences of 12 protein-coding genes were as follow: 14.9% between <i>S. theileri</i> and <i>S. erinaceieuropaei</i>, 14.7% between <i>S. theileri</i> and <i>S. decipiens</i>, and 14.5% between <i>S. theileri</i> with <i>S. ranarum</i>. Divergences of 12 proteins of <i>S. theileri</i> and <i>S. erinaceieuropaei</i> ranged from 2.3% in <i>cox</i>1 to 15.7% in <i>nad</i>5, while <i>S. theileri</i> varied from <i>S. decipiens</i> and <i>S. ranarum</i> by 1.3% in <i>cox</i>1 to 15.7% in <i>nad</i>3. Phylogenetic relationship of <i>S. theileri</i> with eucestodes inferred using the maximum likelihood and Bayesian inferences exhibited identical tree topologies. A clade composed of <i>S. decipiens</i> and <i>S. ranarum</i> formed a sister species to <i>S. erinaceieuropaei</i>, and <i>S. theileri</i> formed a sister species to all species in this clade. Within the diphyllobothridean clade, <i>Dibothriocephalus, Diphyllobothrium</i> and <i>Spirometra</i> formed a monophyletic group, and sister genera were well supported.