The life cycle of the malaria parasite Plasmodium falciparum goes through three developmental stages (schizogony, gametogony and sporogony), each of which presents different environmental constraints that must be met by an adaptive response in the parasite. Here we show that thermoregulation, in which the transcription of select RNAs is upregulated at cooler temperatures, is crucial to the developmental transition that occurs during the transmission of P. falciparum from human to mosquito. Our findings offer new insight into how the malaria parasite senses and reacts to its environment.

1. Growth and Development Section, Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland 20892-0425, USA

Correspondence to: Thomas F. McCutchan e-mail: Email: tmccutchan@niaid.nih.gov