In vivo and in vitro gametocyte production of Plasmodium falciparum isolates from Northern Thailand

► Gametocytes were detected from 100% of patients with acute Plasmodium falciparum malaria. ► All isolated parasite samples maintained their ability to produce gametocytes following adaptation to in vitro culture. ► Sequence analyses of mRNA and genomic DNA of Pfg377, the expression of which occurs exclusively in gametocytes at the blood stage, revealed that not all clones present in an infection were producing gametocytes at the time of sampling.