Effect of ISP3 deletion on the parasite life cycle and on the localisation of ISP1. D) Altered localisation of ISP1 in Δisp3 merozoites. Scale bar  =  5 m. E) ISP1-GFP localisation during each stage of zygote differentiation to ookinete in Δisp3 line. Stage of development (I–VI) is indicated to the left of each row. A Cy3-conjugated antibody to P28 defines the surface of the zygote/ookinete, nuclei were detected using Hoechst dye, and the cells were displayed by differential interference contrast (DIC). Merge is the composite of Hoechst, GFP and P28. Scale bar  =  5 m. F) Localisation of ISP1-GFP in Δisp3 gut and salivary gland sporozoites. Scale bar  =  5 m. G) Relative expression of isp1 and isp3 in Δisp3 parasites compared to wild-type controls using the ΔΔCt method. The level of isp1 mRNA is significantly increased in non-activated gametocytes (P<0.001). Bars represent the mean of 3 biological replicates ± SEM. Schizonts  =  Sch; non-activated gametocytes  =  NA; activated gametocytes  =  AG; ookinetes  =  Ook. ***  =  P<0.001. Poulin B, Patzewitz EM, Brady D, Silvie O, Wright MH, Ferguson DJ, Wall RJ, Whipple S, Guttery DS, Tate EW, Wickstead B, Holder AA, Tewari R. Unique apicomplexan IMC sub-compartment proteins are early markers for apical polarity in the malaria parasite. Biol Open. 2013 2(11):1160-70.. PMID: 24244852