Submitted to: American Association of Veterinary Parasitologists Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: July 11, 1994
Publication Date: N/A
The small ribosomal subunit gene (SSURNA) of S. neurona was amplified using universal primers, and sequenced. The gene was found to be 1806 nt in length, with a G/C content of 46%. Comparison of these sequences to partial sequences of seven other Sarcocystidae was performed by both parsimony and distance matrix analyses. Eimeria tenella and Cryptosporidia were included in the analyses as outgroup species. These analyses confirmed placement of S. neurona in the genus Sarcocystis, and suggested a close relationship to S. muris, S. gigantea and T. gondii. Molecular phylogeny agreed with previous findings based on phenotypic characters that those Sarcocystis spp which utilize the dog (Canis familiaris) as the primary host evolved from a common ancestor, whereas those species (including T. gondii) which utilize the cat (Felis domesticus) as the primary host evolved from another common ancestor. S. neurona is closely related to the group which utilizes the cat as the primary host, suggesting that molecular phylogeny provides clues which may direct the investigation into unknown coccidian life cycles.