8. Golgi complex

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

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 organelle evolved independently.
