Figure 7.

IGF2 acts on FPECs via IGF2R in vivo

(A) Representative double immunostaining for IGF2R (red) and CD31 (green) in Igf2r^ECKO mutant and control Lz at E16 (DAPI, blue; scale bars, 25 μm).

(B) Flow cytometry analysis showing that the majority (>80%) of Igf2r^ECKO mutant feto-placental endothelial cells (FPECs) express YFP (n = 6–14 per genotype).

(C) Fetal and placental growth kinetics in Igf2r^ECKO (Igf2r^fl/+; Tek^+/Cre) mutants compared with Igf2r^fl/+ controls (n = 8–28 conceptuses from n = 3–8 L for each developmental stage).

(D) Proportion and total numbers of FPEC/Lz measured by flow cytometry (n = 6–14 per group).

(E) Representative CD31 staining in E16 Lz (scale bars, 100 μm).

(F) Lz growth kinetics: Igf2r^ECKO (n = 8–16 conceptuses per group).

(G) IGF2 levels (ng/mL) in plasma at E16 (n = 9 per group).

(H) Model summarizing the proposed actions of fetus-, endothelial-, and trophoblast-derived IGF2. For all graphs, data are presented as averages or individual values and error bars represent SD in (B), (D), and (G), or 95% CI in (C) and (F). N.S.— not significant; ^∗p < 0.05; ^∗∗p < 0.01; ^∗∗∗p < 0.001 calculated by two-way ANOVA tests in (B) and (D), mixed effects model in (C) and (F) and Mann-Whitney tests in (G). See also Figure S7 and Video S1.