Plasmodium falciparum blood stage parasites from infected DRAG mice expand in in vitro cultures. A) Giemsa staining of in vitro cultures showing presence of rings (r), trophozoites (t) and schizonts (s) (left and middle panels) and gametocytes (right panel). B) Anopheles stephensi mosquitoes were fed on the gametocyte cultures (four independent membrane feedings) or directly on an infected DRAG mouse (day 28 post-challenge). Oocysts in midgut and sporozoites in salivary glands were examined at days 7 and 14 post-feeding, respectively. Data represent frequency of infected mosquitoes among 25–35 mosquitoes analysed individually. C) Oocysts in midgut of mosquitoes fed on an infected DRAG mouse.