Taxonomy
The taxonomy of this genus and its relationship to other protozoal genera is currently under investigation.
Related genera include: Besnoitia, Caryospora, Cystoisospora, Frenkelia, Isospora, Hammondia, Hyaloklossia, Lankesterella, Neospora and Toxoplasma.
Sarcocystis is the largest genus within the family Sarcocystidae and consists of species which infecting a range of animals including mammals, birds and reptiles. Frenkelia, another genus within this family, consists of parasites that use rodents as intermediate hosts and birds of prey as definitive hosts.
It appears that Besnoitia, Hammondia, Neospora and Toxoplasma form a single clade. Within this clade Toxoplasma and Neospora appear to be sister clades. Isospora also appear to belong to this clade and this clade is a sister to Sarcocystis. Frenkelia appears to be very closely related to Sarcocystis.
Several molecular studies have suggested that Frenkelia is actually a species of Sarcocystis. This genus was distinguished from Sarcocystis on the basis of its tendency to encyst within the brain rather than within muscle. This distinction may not be taxonomically valid.
Within the genus a number of clades have been identified. These include one that contains S. dispersa, S. lacertae, S. mucosa, S. muris, S. neurona and S. rodentifelis. Frenkelia also groups with this clade.
Read more about this topic: Sarcocystis