Intraerythrocytic schizogony of Theileria annulata

Patricia A Conrad, B. G. Kelly, C. G D Brown

Research output: Contribution to journalArticle

23 Citations (Scopus)

Abstract

The intraerythrocytic multiplication of two strains of Theileria annulata was studied with parasites maintained in stationary cultures and in the blood of infected cattle. In cultures established with blood from infected cattle 20–60 % of single T. annulata piroplasms divided into quadruplet forms by day 6 in vitro. Transmission electron microscopic studies of T. annulata in culture showed that piroplasms possess intracytoplasmic food vacuoles and cytostomes during a pre-division trophozoite stage. The onset of intraerythrocytic multiplication was marked by the appearance of rhoptries and electron-dense plaques beneath the parasite's plasmalemmal membrane. The plaques developed into short segments of subplasmalemmal double membranes which were closely associated with the rhoptries. It was concluded that multiplication of T. annulata in erythrocytes occurred by schizogony, as nuclear division preceded cytoplasmic division and the final separation of merozoites. The four merozoites produced by intraerythrocytic schizogony had the same ultrastructural features as the T. annulata merozoites produced by intralymphocytic schizogony. Clusters of four merozoites, identical to those observed in stationary cultures, were also seen in the erythrocytes of persistently infected cattle and appeared to represent the most significant dividing forms of T. annulata in vivo.

Original languageEnglish (US)
Pages (from-to)67-82
Number of pages16
JournalParasitology
Volume91
Issue number1
DOIs
StatePublished - 1985
Externally publishedYes

Fingerprint

Theileria annulata
schizogony
Merozoites
merozoites
Piroplasmida
cattle
Parasites
erythrocytes
Erythrocytes
electrons
Electrons
Cell Nucleus Division
parasites
Trophozoites
trophozoites
Cytokinesis
Membranes
blood
Vacuoles
vacuoles

ASJC Scopus subject areas

  • Parasitology
  • Infectious Diseases
  • Animal Science and Zoology

Cite this

Intraerythrocytic schizogony of Theileria annulata. / Conrad, Patricia A; Kelly, B. G.; Brown, C. G D.

In: Parasitology, Vol. 91, No. 1, 1985, p. 67-82.

Research output: Contribution to journalArticle

Conrad, Patricia A ; Kelly, B. G. ; Brown, C. G D. / Intraerythrocytic schizogony of Theileria annulata. In: Parasitology. 1985 ; Vol. 91, No. 1. pp. 67-82.
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