The molecular mechanisms of giardia encystation.

The protozoan parasite Giardia lamblia is transmitted as an environmentally resistant cyst. The encystation process is attracting attention not only from the viewpoint of disease transmission, but also as a model for differentiation. Here, Hugo Luján, Michael Mowatt and Theodore Nash discuss molecular events underlying this process, including the induction of expression and transport of cyst wall proteins and the induction of Golgi-like activity. They also propose that the signal for encystation derives from cholesterol deprivation in the lower small intestine.