In the initial 16 hours, zygote/ookinete development appeared to be normal. However, advanced retort-forms showed abnormal development as the protruding area swelled up leaving a bottleneck between the latter and the remnant zygote body. This bottleneck did not prevent the migration of the nucleus leading to ookinetes that were typically wider than WT ookinetes with a bulging area mostly in the anterior part of the cell. None of the mutant ookinetes were found to display the typical banana shape of WT ookinetes. Apart from the global shape abnormality, IMC1h-KO ookinetes appeared to possess a complete set of organelles and the assembly of the subpellicular microtubule and IMC appeared unaffected by the gene disruption. Ookinetes showed abnormal gliding behaviour.Ookinetes showed a 15-fold decrease in traversal of the midgut epithelium.

Normal numbers of ookinetes are produced. Mature ookinetes showed abnormal morphology. Ookinetes were wider, shorter and possessed a bulging area typically in the central part of the cell. Infectivity of ookinetes was reduced (ookinetes produced ~30-fold less oocysts in A. stephensi).

Ookinetes showed a 15-fold decrease in traversal of the midgut epithelium.The number of IMC1h-KO oocysts in infected mosquitoes was 20-fold lower than in mosquitoes infected with WT parasites. Mutant ookinetes that reached the basal epithelium developed into oocysts of normal size and morphology that gave rise to sporozoites.

Infectivity of ookinetes was reduced (ookinetes produced ~30-fold less oocysts in A. stephensi). Oocysts appeared to develop normally, forming large numbers of sporozoites. However, all sporozoites were of abnormal shape, typically possessing a bulging area near the middle of the sporozoite. No sporozoites were detected in salivary glands.

Mutant ookinetes that reached the basal epithelium developed into oocysts of normal size and morphology that gave rise to sporozoites.Sporozoites invaded salivary glands but midgut IMC1h-KO sporozoites were four times less invasive than WT sporozoites. All IMC1h-KO sporozoites obtained from both oocysts and salivary glands had an abnormal shape, with a protruding bulge of variable size at the posterior end containing the nucleus.IMC1h-KO sporozoites showed gliding motility defects.IMC1h-KO sporozoites are able to invade hepatocytes but are not able to progress through the dermis in vivo. IMC1h-KO sporozoites are able to transmigrate and invade hepatoma-cells in vitro but liver stages show developmental defects.

Oocysts appeared to develop normally, forming large numbers of sporozoites. However, all sporozoites were of abnormal shape, typically possessing a bulging area near the middle of the sporozoite. No sporozoites were detected in salivary glands.

IMC1h-KO sporozoites are able to invade hepatocytes but are not able to progress through the dermis in vivo. IMC1h-KO sporozoites are able to transmigrate and invade hepatoma-cells in vitro but liver stages show developmental defects.