Skip to main content
    • Aa
    • Aa

Sex determination and sex differentiation in coccidia: gametogony and oocyst production after monoclonal infection of cats with free-living and intermediate host stages of Isospora (Toxoplasma) gondii

  • A. W. C. A. Cornelissen (a1) and J. P. Overdulve (a1)

Clones of single oocysts, single sporocysts, single sporozoites, single proliferative parasites, single cysts and single cystozoites of Isospora (Toxoplasma) gondii (KB-strain) were made under visual control using a de Fonbrune micromanipulator. Cloning was successful in 28, 32, 21, 8, 54 and 7% of the trials, respectively. All clones were used for monoclonal infection in non-immune conventionally reared (CV) or specified pathogen-free (SPF) cats. Pre-patent and patent periods, sporulation percentages of excreted oocysts, mouse infectivity of sporulated oocysts, antibody response and immunity to reinfection of CV cats were determined. For these parameters almost no differences were observed between monoclonal infections and infections described with the non-cloned KB-strain. In all cats autopsied during the patent period, 5–8 days post-infection, macrogametes, microgametes and oocysts were found. Since meiosis occurs during sporulation and since all free-living and intermediate host stages proved to be bisexual, it is concluded that sex differentiation in I. (T) gondii is not determined by segregation of sex chromosomes or sex genes but is caused by some final host factor(s) that induce(s) differential gene expression in genetically identical cells.

Linked references
Hide All

This list contains references from the content that can be linked to their source. For a full set of references and notes please see the PDF or HTML where available.

E. D. Box (1977). Life cycles of two Isospora species in the canary (Serinus canarius Linnaeus). Journal of Protozoology 24, 5767.

H. D. Chapman (1978). Studies on excystation of different species of Eimeria in vitro. Zeitschrift für Parasitenkunde 56, 115–21.

A. W. C. A. Cornelissen & J. P. Overdulve (1981). Sex determination and sex differentiation in Isospora (Toxoplasma) gondii. Transactions of the Royal Society of Tropical Medicine and Hygiene 75, 594–6.

J. P. Dubey (1976). Reshedding of Toxoplasma gondii oocysts by chronically infected cats. Nature, London 262, 213–14.

J. P. Dubey & J. K. Frenkel (1972). Cyst-induced toxoplasmosis in cats. Journal of Protozoology 19, 155–72.

A. Haberkorn (1970). Die Entwicklung von Eimeria falciformis (Eimer 1870) in der weissen Maus (Mus niusculus). Zeitschrift für Parasitenkunde 34, 4967.

T. K. Jeffers (1975). Attenuation of Eimeria tenella through selection for precociousness. Journal of Parasitology 61, 1083–90.

E.-H. Lee & M. A. Fernando (1978). Immunogenicity of a single sporocyst of Eimeria maxima. Journal of Parasitology 64, 483–5.

E.-H. Lee , O. Remmler & M. A. Fernando (1977). Sexual differentiation in Eimeria tenella (Sporozoa: Coccidia). Journal of Parasitology 63, 155–6.

N. D. Levine (1978). Perkinsus gen.n. and other new taxa in the protozoan phylum Apicomplexa. Journal of Parasitology 64, 549.

P. L. Long (1959). A study of Eimeria maxima Tyzzer, 1929, a coccidium of the fowl (Gallus gallus). Annals of Tropical Medicine and Parasitology 53, 325–33.

E. R. Pfefferkorn & L. C. Pfefferkorn (1976). Toxoplasma gondii: Isolation and preliminary characterization of temperature-sensitive mutants. Experimental Parasitology 39, 365–76.

E. R. Pfefferkorn , L. C. Pfefferkorn & E. D. Colby (1977). Development of gametes and oocysts in cats fed cysts derived from cloned trophozoites of Toxoplasma gondii. Journal of Parasitology 63, 158–9.

L. C. Pfefferkorn & E. R. Pfefferkorn (1980). Toxoplasma gondii: genetic recombination between drug resistant mutants. Experimental Parasitology 50, 305–16.

W. Reyer (1937). Infektionsversuche mit Barrouxia schneideri an Lithobius forcicatus, insbesondere zur Frage der Sexualität der Coccidiensporozoiten. Zeit schrift für Parasitenkunde 9, 478522.

M. W. Shirley (1980). Maintenance of Eimeria maxima by serial passage of single sporocysts. Journal of Parasitology 66, 172–3.

Recommend this journal

Email your librarian or administrator to recommend adding this journal to your organisation's collection.

  • ISSN: 0031-1820
  • EISSN: 1469-8161
  • URL: /core/journals/parasitology
Please enter your name
Please enter a valid email address
Who would you like to send this to? *


Full text views

Total number of HTML views: 0
Total number of PDF views: 3 *
Loading metrics...

Abstract views

Total abstract views: 42 *
Loading metrics...

* Views captured on Cambridge Core between September 2016 - 23rd May 2017. This data will be updated every 24 hours.