(Hasselmann, 1923) Wenyon, 1926: redescription, molecular characterization and deposition of life cycle stages specimens in the Smithsonian Museum.

Abstract

Currently, 7 namedspecies infect cattle:,,,,,and; other, unnamed species also infect cattle. Of these parasites of cattle, a complete life cycle description is known only for, the most pathogenic species in cattle. The life cycle ofwas completed experimentally in 1982, before related parasite species were structurally characterized, and before the advent of molecular diagnostics; to our knowledge, no archived frozen tissues from the cattle employed in the original descriptions remain for DNA characterization. Here, we isolated DNA from a paraffin-embedded kidney of a calf experimentally infected within 1980; we then sequenced portions of 18S rRNA, 28S rRNA, COX1 and Acetyl CoA genes and verified that each shares 99–100% similarity to other available isolates attributed tofrom naturally infected cattle. We also reevaluated histological sections of tissues of calves experimentally infected within the original description, exploiting improvements in photographic technology to render clearer morphological detail. Finally, we reviewed all available studies of the life cycle of, noting thatwas transmitted between bison () and cattle () and that the strain of parasite derived from bison appeared more pathogenic than the cattle strain. Based on these newfound molecular, morphological and physiological data, we thereby redescribedand deposited reference material in the Smithsonian Museum for posterity.