Fig. 4: Daily rhythms in motility-associated genes and infection efficiency.
From: Parasite and vector circadian clocks mediate efficient malaria transmission
a, The most significant biological functions with a cycling expression profile in DD and LD. Sporozoite schematics. ER, endoplasmic reticulum. b, Rhythmic expression profile of transcripts. c, The percentage of mosquitos that ingested blood within cups at ZT4 (daytime) and ZT16 (nighttime) (n = 9/10 cups per timepoint, n = 6–16 mosquitos per cup, Mann–Whitney test, **P < 0.005, two-tailed). Data are presented as mean ± s.e.m. d, Quantification of haemoglobin in mosquito midguts, as a proxy of blood ingested after mosquito access to a bloodmeal for 30 min (n = 67–68 midguts per group; four independent experiments with two replicates per timepoint; Mann–Whitney test, ***P = 0.0081, two-tailed). Data are presented as mean ± s.e.m. e, Quantification of haemoglobin (normalized to daytime median) in each engorged mosquito midgut, as a proxy of blood ingested, after a 30-min bloodmeal (n = 33–50 engorged midguts per group; four independent experiments; Mann–Whitney test, **P = 0.0082, two-tailed). For both d and e, each data point represents quantified haemoglobin from one mosquito midgut. Data are presented as median, and error bars represent 95% confidence intervals. f, Quantification by qPCR of parasite liver load in infected mice upon intradermal injection of sporozoites at ZT4 (daytime) and ZT16 (nighttime) in matched or mismatched schedules. The 18S expression was normalized against Hprt (n = 10–23 mice per group, three independent experiments, error bars represent ±s.e.m., two-tailed t-test, **P = 0.0024, two-way ANOVA shows significance for host timing, ***P = 0.003, Benjamini–Hochberg (FDR) method to correct for multiple comparisons). g, Parasite load in non-synchronized Hepa 1-6 cells upon infection with sporozoites at daytime or nighttime, assessed by qPCR normalized against Gapdh (n = 9 wells, error bars represent ±s.e.m. from four independent experiments; n.s., non-significant, Mann–Whitney test, two-tailed). h, Hepa 1-6 cells expressing luciferase under Bmal1 promoter were cultured and entrained with temperature (n = 12 wells, error bars represent ±s.e.m. from one representative experiment). RLU, relative light units. i, Hepa 1-6 wild-type cells were entrained with temperature and infected with matching day versus night sporozoites. Parasite load was assessed by qPCR normalized against Gapdh (n = 9 wells, error bars represent ±s.e.m., two independent experiments, **P = 0.0056, Mann–Whitney test, two-tailed).
