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  • The EMBO Journal (2002) 21, 1586 - 1596
  • doi:10.1093/emboj/21.7.1586

Levels of circumsporozoite protein in the Plasmodium oocyst determine sporozoite morphology

Vandana Thathy1,2, Hisashi Fujioka3, Soren Gantt1, Ruth Nussenzweig4, Victor Nussenzweig1 and Robert Ménard5

  1. Department of Pathology, Michael Heidelberger Division of Immunology, New York University School of Medicine, New York, NY 10016, USA
  2. Departments of Medicine and of Microbiology and Immunology, Albert Einstein College of Medicine, Bronx, NY 10461, USA
  3. Institute of Pathology, Case Western Reserve University, Cleveland, OH 44106, USA
  4. Department of Medical and Molecular Parasitology, New York University School of Medicine, New York, NY 10010, USA
  5. Unité de Biologie et Génétique du Paludisme, Institut Pasteur, 75724 Paris Cedex 15, France

Correspondence to:

Robert Ménard, E-mail: rmenard@pasteur.fr

Received 10 January 2002; Accepted 14 February 2002; Revised 14 February 2002

The sporozoite stage of the Plasmodium parasite is formed by budding from a multinucleate oocyst in the mosquito midgut. During their life, sporozoites must infect the salivary glands of the mosquito vector and the liver of the mammalian host; both events depend on the major sporozoite surface protein, the circumsporozoite protein (CS). We previously reported that Plasmodium berghei oocysts in which the CS gene is inactivated do not form sporozoites. Here, we analyzed the ultrastructure of P.berghei oocyst differentiation in the wild type, recombinants that do not produce or produce reduced amounts of CS, and corresponding complemented clones. The results indicate that CS is essential for establishing polarity in the oocyst. The amounts of CS protein correlate with the extent of development of the inner membranes and associated microtubules underneath the oocyst outer membrane, which normally demarcate focal budding sites. This is a first example of a protein controlling both morphogenesis and infectivity of a parasite stage.

  • Keywords:

    • budding,
    • cell division,
    • circumsporozoite protein,
    • Plasmodium berghei,
    • sporozoite