Giardia intestinalis is a pathogenic protozoan, which is the causative agent of giardiasis. The Giardia trophozoite presents a cytoskeleton formed by specialized microtubular structures such as the ventral disk, four pairs of flagella, the median body, and the funis that are involved in cell division and differentiation. Because trophozoite motility and adhesion to the host intestinal cells are important processes mediated by the parasite cytoskeleton, the fine regulation of these elements may be directly related to the mechanisms that underlie infection. The organization of Giardia cytoskeleton at the ultrastructural level has been analyzed by different classical microscopy methods, including negative stain and chemical fixation for scanning and transmission electron microscopy. In this chapter, we provide an overview of the G. intestinalis cytoskeleton, emphasizing its structural organization and proteins involved in the maintenance of the structures as well as their functional role. These structures have been recently analyzed in some detail using techniques such as electron microscopy tomography, cryoelectron microscopy, ultra-high resolution scanning electron microscopy (UHRSEM), and helium ion microscopy (HIM). In addition, genome survey and phylogenetic analysis as well as proteomic analysis have revealed the presence of several new and not yet well-characterized proteins.
Part of the book: Giardiasis