IDENTIFICATION OF SYNAPOMORPHIC CHARACTERS IN THE GENUS SARCOCYSTIS BASED ON 18S RDNA SEQUENCE COMPARISON

In order to further investigate synapomorphic characters in the genus Sarcocystis, the small subunit ribosomal RUA gene sequences of Sarcocy stis capracanis and Sarcocystis moulei were determined and used to inf er the phylogenetic position of these two organisms within the cyst-fo rming coccidia. Phylogenies derived using distance, maximum parsimony and maximum likelihood methods demonstrated that S. capracanis groups with Sarcocystis tenella and Sarcocystis arieticanis as a clade that s hares the characteristic of using canids as their definitive host. S. moulei was shown to group with Sarcocystis gigantea and Sarcocystis fu siformis as a clade that shares the characteristic of using felids as their definitive host.