title: Toxoplasma gondii sequesters centromeres to a specific nuclear region throughout the cell cycle.
abstract: Members of the eukaryotic phylum Apicomplexa are the cause of important human diseases including malaria, toxoplasmosis, and cryptosporidiosis. These obligate intracellular parasites produce new invasive stages through a complex budding process. The budding cycle is remarkably flexible and can produce varied numbers of progeny to adapt to different host-cell niches. How this complex process is coordinated remains poorly understood. Using Toxoplasma gondii as a genetic model, we show that a key element to this coordination is the centrocone, a unique elaboration of the nuclear envelope that houses the mitotic spindle. Exploiting transgenic parasite lines expressing epitope-tagged centromeric H3 variant CenH3, we identify the centromeres of T. gondii chromosomes by hybridization of chromatin immunoprecipitations to genome-wide microarrays (ChIP-chip). We demonstrate that centromere attachment to the centrocone persists throughout the parasite cell cycle and that centromeres localize to a single apical region within the nucleus. Centromere sequestration provides a mechanism for the organization of the Toxoplasma nucleus and the maintenance of genome integrity.
authors.affiliation: Center for Tropical and Emerging Global Diseases and Department of Cellular Biology, University of Georgia, Athens, GA 30602, USA.
authors.forename: Carrie F
authors.initials: CF
authors.lastname: Brooks
authors.forename: Maria E
authors.initials: ME
authors.lastname: Francia
authors.forename: Mathieu
authors.initials: M
authors.lastname: Gissot
authors.forename: Matthew M
authors.initials: MM
authors.lastname: Croken
authors.forename: Kami
authors.initials: K
authors.lastname: Kim
authors.forename: Boris
authors.initials: B
authors.lastname: Striepen
mesh_terms: D002453:Cell Cycle / Q000187:drug effects; D002503:Centromere / Q000187:drug effects / Q000378:metabolism*; D047369:Chromatin Immunoprecipitation; D019457:Chromosome Breakage / Q000187:drug effects; D005047:Etoposide / Q000494:pharmacology; D005455:Fluorescent Antibody Technique; D006657:Histones / Q000378:metabolism; D006801:Humans; D008239:Lysine / Q000378:metabolism; D008745:Methylation / Q000187:drug effects; D008938:Mitosis / Q000187:drug effects; D020411:Oligonucleotide Array Sequence Analysis; D015203:Reproducibility of Results; D014122:Toxoplasma / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism*
chemical_list: D006657:Histones; D005047:Etoposide; D008239:Lysine