We previously reported that Neospora caninum can be induced to express BAG1, a bradyzoite antigen, within 3 days of culture under stress conditions. The main goals of the present experiment were to increase the expression of BAG1 in vitro (in part by extending cultures for 9 days), to observe parasitophorous vacuoles at various points of stage differentiation, and to test the ability of organisms produced in vitro to function like mature bradyzoites. Expression of BAG1 and of a tachyzoite antigen (NcSAG1) was monitored using a double-label immunofluorescence assay. For the purpose of this study, organisms expressing NcSAG1 were designated as tachyzoites, those expressing BAG1 were designated as bradyzoites, and those expressing both antigens were designated as intermediate zoites. The greatest percentage of intermediate zoites and bradyzoites (14%) occurred in bovine monocytes maintained for 9 days. These bradyzoites did not appear to be functionally mature; they did not induce patent infections in dogs, in contrast to bradyzoites that were produced in chronically infected mice. In vitro, large parasitophorous vacuoles contained either a pure population of tachyzoites or a mixture of tachyzoites and intermediate zoites, which is indicative of asynchronous stage conversion of organisms within a vacuole. Bradyzoites were first observed within small vacuoles on day 6, and bradyzoites never shared vacuoles with tachyzoites. This finding suggests that vacuoles containing bradyzoites may develop only if the cell is invaded by a zoite that has already begun bradyzoite differentiation. An alternative possibility is that cysts may develop if the establishing tachyzoite undergoes bradyzoite differentiation before multiplying. Cysts do not appear to arise from transformation of tachyzoites within large parasitophorous vacuoles.
Skip Nav Destination
Article navigation
December 2002
Research Article|
December 01 2002
NEOSPORA CANINUM IN VITRO: EVIDENCE THAT THE DESTINY OF A PARASITOPHOROUS VACUOLE DEPENDS ON THE PHENOTYPE OF THE PROGENITOR ZOITE
S. S. Tunev
;
S. S. Tunev
Department of Veterinary Pathobiology, College of Veterinary Medicine, University of Illinois, 2001 S. Lincoln Avenue, Urbana, Illinois 61802. mmmcalli@uiuc.edu
Search for other works by this author on:
M. M. McAllister
;
M. M. McAllister
Department of Veterinary Pathobiology, College of Veterinary Medicine, University of Illinois, 2001 S. Lincoln Avenue, Urbana, Illinois 61802. mmmcalli@uiuc.edu
* To whom correspondence should be addressed
Search for other works by this author on:
R. C. Anderson-Sprecher
;
R. C. Anderson-Sprecher
Department of Veterinary Pathobiology, College of Veterinary Medicine, University of Illinois, 2001 S. Lincoln Avenue, Urbana, Illinois 61802. mmmcalli@uiuc.edu
† Department of Statistics, University of Wyoming, Laramie, Wyoming 82071
Search for other works by this author on:
L. M. Weiss
L. M. Weiss
Department of Veterinary Pathobiology, College of Veterinary Medicine, University of Illinois, 2001 S. Lincoln Avenue, Urbana, Illinois 61802. mmmcalli@uiuc.edu
‡ Department of Pathology, Division of Parasitology and Tropical Medicine, Albert Einstein College of Medicine, Bronx, New York 10461
Search for other works by this author on:
J Parasitol (2002) 88 (6): 1095–1099.
Citation
S. S. Tunev, M. M. McAllister, R. C. Anderson-Sprecher, L. M. Weiss; NEOSPORA CANINUM IN VITRO: EVIDENCE THAT THE DESTINY OF A PARASITOPHOROUS VACUOLE DEPENDS ON THE PHENOTYPE OF THE PROGENITOR ZOITE. J Parasitol 1 December 2002; 88 (6): 1095–1099. doi: https://doi.org/10.1645/0022-3395(2002)088[1095:NCIVET]2.0.CO;2
Download citation file:
Sign in
Don't already have an account? Register
Client Account
You could not be signed in. Please check your email address / username and password and try again.
Sign in via your Institution
Sign in via your InstitutionCiting articles via
REVIEW OF PARASITES FOUND IN EXTINCT ANIMALS: WHAT CAN BE REVEALED
Paula Cascardo, Elisa Pucu, Daniela Leles
THE EFFICACY OF MARINE NATURAL PRODUCTS AGAINST PLASMODIUM FALCIPARUM
Yukihiro Goto, Rie Kamihira, Yoichi Nakao, Motohiro Nonaka, Ryo Takano, Xuenan Xuan, Kentaro Kato
MORPHOLOGICAL AND MOLECULAR CHARACTERIZATION OF THE PLAGUE VECTOR XENOPSYLLA BRASILIENSIS
Saeed Mohammadi, Heike Lutermann, Sasha Hoffmann, Arsalan Emami-Khoyi, Heather J. Webster, Dina Fagir, Nigel C. Bennett, Bettine Jansen van Vuuren
MOLECULAR INVESTIGATION AND PHYLOGENETIC ANALYSIS OF ANAPLASMOSIS IN DOGS
Hammad Nayyar Ghauri, Muhammad Ijaz, Arslan Ahmed, Muhammad Umair Aziz Muhammad Naveed, Yasir Nawab, Muhammad Umar Javed, Awais Ghaffar
GENETIC AND MORPHOLOGIC CHARACTERIZATION OF DIASCHISTORCHIS PANDUS (DIGENEA: PRONOCEPHALIDAE) TREMATODES EXTRACTED FROM HAWKSBILL TURTLES, ERETMOCHELYS IMBRICATA (TESTUDINES: CHELONIIDAE), IN GRENADA, WEST INDIES
Daniel M. Fitzpatrick, Monica A. Tetnowski, Thomas G. Rosser, Rhonda D. Pinckney, David P. Marancik, Brian P. Butler