Figure 6.

Mutations in Fatty Acid Elongation Disrupt Mosquito- and Liver-Stage Development

(A) Pathway map for elongation of fatty acids (FAE) in the Plasmodium endoplasmic reticulum. See Table S4 for gene IDs, enzyme functions, and reactions. Blood-stage screen data suggested KCR to be essential, but we here correct the phenotype to dispensable, since a genotyped ΔKCR parasite shows comparable blood-stage growth to control parasites (Figure S5A).

(B) Schematic representation of developmental blocks for single KOs and ΔKCR sporozoites derived from a ΔKCR × WT genetic cross. Green, phenotype not significantly different from WT. Red, block in life-cycle progression, except for liver stage, where red indicates phenotype significantly different from WT (>2-day delay in pre-patent period).

(C) Size of cultured liver stages (48 hpi) of 250 EEFs. Median and interquartile ranges in red. ^∗p < 0.05 by Kruskal-Wallis test.

(D) Relative maturation of EEFs measured as conversion of infected host cells to detached cells at 48 hpi. Error bars show standard deviations from 3 biological replicates (for ELO-A) or 8 biological replicates (all other mutants). The results were statistically evaluated by a one-way analysis of variance (ANOVA) test with Dunnet’s multiple comparisons (^∗∗∗p ≤ 0.001).

(E) The number of mice with blood infection after injection of 5,000 sporozoites and the mean delay (range) in pre-patency compared to mice infected with WT sporozoites. ^∗, gene KO parasites with a significantly “slow” blood-stage phenotype (Bushell et al., 2017). See Figure S5E for plots showing the course of blood-stage infections after sporozoite injection.