Pink or blue: sex determination in malaria gametocytes.

Sex determination in eukaryotes defines whether an organism develops as male or female and is shaped by genetic and environmental factors. In the malaria parasite Plasmodium, recent data suggest that sex determination is decided at two critical checkpoints. First, chromatin remodeling activates the master regulator AP2-G, triggering a transcriptional cascade that commits the parasites to sexual development and drives the expression of genes crucial for male and female gametocytes. Second, post-transcriptional processes - including the stabilization and suppression of transcript via RNA-binding proteins - guide the branching into male or female gametocytes through threshold-trait-dependent mechanisms. This review highlights recent advances in understanding the molecular mechanisms that regulate the two checkpoints of sex determination in malaria gametocytes.