Switching Plasmodium falciparum genes on and off for erythrocyte invasion.

Culture-adapted lines of the malaria parasite Plasmodium falciparum use alternative pathways for the invasion of erythrocytes. The expression of parasite ligands that are involved in the different pathways varies among parasite lines. Recently, several studies have attempted to characterize the use of different invasion pathways and the expression of specific invasion ligands in field isolates, opening the way to understand how invasion occurs in natural infections. In this review, these findings are discussed in the context of the most recent data on invasion by culture-adapted parasites to describe the current understanding of how wild parasites invade, how the variant expression of invasion ligands relates to switching between alternative invasion pathways and why so many different pathways are needed.