Genetic rescue of a Toxoplasma gondii conditional cell cycle mutant

Michael W. White, Maria E. Jerome, Shipra Vaishnava, Michael Guerini, Michael Behnke, Boris Striepen

Research output: Contribution to journalArticle

26 Scopus citations

Abstract

Growth rate is a major pathogenesis factor in the parasite Toxoplasma gondii; however, how cell division is controlled in this protozoan is poorly understood. Herein, we show that cenfrosomal duplication is an indicator of S phase entry while centrosome migration marks mitotic entry. Using the pattern of centrosomal replication, we confirmed that mutant ts11C9 undergoes a bimodal cell cycle arrest that is characterized by two subpopulations containing either single or duplicated centrosomes which correlate with the bipartite genome distribution observed at the non-permissive temperature. Genetic rescue of ts11C9 was performed using a parental RH strain cDNA library, and the cDNA responsible for conferring temperature resistance (growth at 40°C) was recovered by recombination cloning. A single T. gondii gene encoding the protein homologue of XPMC2 was responsible for genetic rescue of the temperature-sensitive defect in ts11C9 parasites. This protein is a known suppressor of mitotic defects, and in tachyzoites, TgXPMC2-YFP localised to the parasite nucleus and nucleolus which is consistent with the expected subcellular localization of critical mitotic factors. Altogether, these results demonstrate that ts11C9 is a conditional mitotic mutant containing a single defect which influences two distinct control points in the T. gondii tachyzoite cell cycle.

Original languageEnglish (US)
Pages (from-to)1060-1071
Number of pages12
JournalMolecular Microbiology
Volume55
Issue number4
DOIs
StatePublished - Feb 1 2005

ASJC Scopus subject areas

  • Microbiology
  • Molecular Biology

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    White, M. W., Jerome, M. E., Vaishnava, S., Guerini, M., Behnke, M., & Striepen, B. (2005). Genetic rescue of a Toxoplasma gondii conditional cell cycle mutant. Molecular Microbiology, 55(4), 1060-1071. https://doi.org/10.1111/j.1365-2958.2004.04471.x