Sarcocystis species in red deer revisited: with a re-description of two known species as Sarcocystis elongata n. sp. and Sarcocystis truncata n. sp. based on mitochondrial cox1 sequences.

In a previous investigation, five Sarcocystis species were described from Norwegian red deer and believed to be conspecific with species occurring in either reindeer or moose based on sarcocyst morphology and nucleotide sequences of the nuclear ribosomal DNA unit. The aim of the present study was to characterize numerous isolates of these sarcocyst types at the mitochondrial cytochrome c oxidase subunit I gene (cox1) in order to corroborate or refute previous species designations of Sarcocystis in red deer. The Sarcocystis tarandi- and Sarcocystis rangiferi-like taxa in red deer and reindeer, respectively, were thoroughly compared by sequencing 14-27 isolates of each type. Sequence comparisons revealed four distinct sequence types, which by phylogenetic analyses were placed in four monophyletic groups according to host origin, and they were therefore considered to represent four separate species. The two taxa of this type in red deer were named Sarcocystis elongata and Sarcocystis truncata, respectively. Sequencing of many isolates of Sarcocystis hjorti and Sarcocystis ovalis from red deer and moose confirmed that these species occur in both hosts. A revised description of the two new species is given and the current knowledge concerning all six Sarcocystis species in red deer is reviewed.