Normal production of gametocytes. Normal fertilization rate and ookinete production. ookinete infectivity is decreased (200 fold reduction in oocyst production). Ookinetes penetrate the epithelial cells of the mosquito midgut but are affected in migration through the cytoplasm of the epithelial cell to the basal lamina.

Normal gametocyte and ookinete production. Surprisingly PPy s4/celtos parasites also established a low-level mosquito midgut infection.

Normal gametocyte and ookinete production. Surprisingly PPy s4/celtos parasites also established a low-level mosquito midgut infection.

The number of oocysts is decreased by ~200 fold compared to wild type as a result of decreased infectivity of ookinetes (see phenotype 'Fertilization and ookinete'). Oocysts produce normal numbers of sporozoites that are not affected in their infectivity to salivary glands.

Normal gametocyte and ookinete production. Surprisingly Py s4/celtos parasites also established a low-level mosquito midgut infection. Whereas the number of oocysts per midgut stayed stable between days 7 11 for Py WT, oocyst numbers for Py s4/celtos parasites declined throughout this period. The fraction of midguts infected with Py s4/celtos declined markedly from day 7 - 11, by which time oocysts were only occasionally observed and these exhibited defects in sporulation compared to Py WT oocysts. Combined, the data suggest that Py S4/CelTOS has an important role during oocyst survival and/or sporogenesis in addition to the previously reported role in ookinete traversal of the midgut epithelium.

Normal gametocyte and ookinete production. Surprisingly Py s4/celtos parasites also established a low-level mosquito midgut infection. Whereas the number of oocysts per midgut stayed stable between days 7 11 for Py WT, oocyst numbers for Py s4/celtos parasites declined throughout this period. The fraction of midguts infected with Py s4/celtos declined markedly from day 7 - 11, by which time oocysts were only occasionally observed and these exhibited defects in sporulation compared to Py WT oocysts. Combined, the data suggest that Py S4/CelTOS has an important role during oocyst survival and/or sporogenesis in addition to the previously reported role in ookinete traversal of the midgut epithelium.

The number of oocysts is decreased by ~200 fold compared to wildtype as a result of decreased infectivity of ookinetes (see phenotype 'Fertilization and ookinete'). Oocysts produce normal numbers of sporozoites that are not affected in their infectivity to salivary glands.Motility of sporozoites was normal. Infectivity of sporozoites as measured by infection of rats (Wistar) by intravenous inoculation of sporozoites was reduced (~1/20 to ~1/50 of wild type sporozoites). Infectivity to HepG2 cells in vitro was not affected (similar numbers of EEFs were formed). However, cell traversal (cell-passage) was strongly impaired (as measured by the 'cell wound assay').Infectivity of sporozoites to rats (Wistar) was restored in Kupffer cell-depleted rats.

No salivary gland sporozoites.

No salivary gland sporozoites.

Infectivity of sporozoites as measured by infection of rats (Wistar) by intravenous inoculation of sporozoites was reduced (~1/20 to ~1/50 of wildtype sporozoites). Infectivity to HepG2 cells in vitro was not affected (similar numbers of EEFs were formed). However, cell traversal (cell-passage) was strongly impaired (as measured by the 'cell wound assay').Infectivity of sporozoites to rats (Wistar) was restored in Kupffer cell-depleted rats.