Anti-PfRH1 mAbs inhibit invasion before junction formation. (c,d) Snapshots taken from time-lapse live movie microscopy of invasion of W2mef by merozoites in the absence (c) or presence (d) of C49 mAb. Time-elapsed post schizont rupture is indicated in each snapshot in seconds (sec, white). A white dotted circle indicates a rupturing schizont. Green arrows point to merozoites. A red dotted circle around an erythrocyte is added to help follow the infection. Scale bars¼5 mM. (c) In the absence of mAb, the merozoite released from a mature schizont (white cycle) attaches, apically reorients and penetrates into an uninfected erythrocyte. Following successful invasion, deformation of infected erythrocytes occurs (echinocytosis) and by 2 min the erythrocytes recover back to its normal shape. (d) In the presence of C49, the merozoite released from a mature schizont attaches and apically reorients, but it is unable to penetrate the erythrocyte even after 3 min.

Gao X, Gunalan K, Yap SS, Preiser PR. Triggers of key calcium signals during erythrocyte invasion by Plasmodium falciparum. Nat Commun. 2013;4:2862.