Author details

Thus, the current knowledge concerning mitosomes is still limited. There are a number of unanswered questions related to the biology of this organelle and its proteins as well as related

There is still controversy regarding the presence of a Golgi complex in G. intestinalis. This organelle is usually characterized by the presence of several stacked cisternae, which are often located around the nucleus and close to the endoplasmic reticulum. Until now, an organelle

Some groups proposed a similarity between the ESVs and the Golgi complex [47, 52, 63–65] supported by: (1) COPI and COPII association with the ESVs [47]; (2) the ESVs are sensitive for Brefeldin A, a drug known to inhibits the anterograde Golgi cisternae movement [63]; (3) the ESVs dependence of GTPases Sar1 and Arf1 for biogenesis and maturation, respectively [64]. However, the ESVs present some characteristics that do not fit with those presented by a classical Golgi: (1) the ESVs appear only during the encystation process; (2) no classical Golgi markers such as GM130, galactosyl transferases or the trans-Golgi network marker Rab6 are present in the parasite; (3) the ESVs do not present morphological characteristics that define this organelle as a Golgi, in accordance with parameters that have been well defined for many years. This is considered a strong argument for the absence of a typical Golgi in G. intestinalis [65]. Thus, it is hard to directly test if the ESVs are in fact similar to the Golgi complex or if this

The endomembrane system of Giardia is well adapted to changes that are encountered in the gut environment and outside the warm and nutritious body. The cysts ensure the efficacy of the parasite in host colonization. Despite the low complexity of organelles and machinery involved, G. intestinalis constitutes a model for the investigation of synthesis, transport and

There are several questions to be answered regarding the biology of Giardia—for example, the right pathway of endocytic and exocytic materials, the formation of the cyst wall, each protein segregation and polymerization in the formation of the cyst wall, the glycosylation phenomena of secreted proteins, the role of each nucleus in the whole process of the Giardia life cycle,

This work was supported by the Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq), Financiadora de Estudos e Projetos (FINEP), Fundação Carlos Chagas Filho

to the importance of mitosomes in the parasite life cycle.

that fits with these criteria has not been identified in G. intestinalis.

assembly of simple but highly effective biopolymers [43, 52].

8. Golgi complex

102 Current Topics in Giardiasis

organelle evolved independently.

9. Final remarks

among others.

Acknowledgements

Victor Midlej1,3,4\*, Wanderley de Souza1,3,4 and Marlene Benchimol1,2,3,4

\*Address all correspondence to: marlenebenchimol@gmail.com or vmidlej@hotmail.com


3 Instituto Nacional de Ciência e Tecnologia em Biologia Estrutural e Bioimagens-INBEB, Rio de Janeiro, Brazil

4 Centro Nacional de Bioimagens-CENABIO, Rio de Janeiro, Brazil

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**Provisional chapter**
