Fig. 2

Cell Proliferation and Survival in the Axial Vessels Do Not Appear to Be Affected by Gain or Loss of Function of Ifng1-2 Signaling

(A–C) ifng1-2 overexpression increases HSC number without affecting cell division. HSCs (itga2b:EGFP⁺kdrl:HRAS-mCherry⁺, green⁺red⁺) that exit the G0 phase, labeled by PCNA immunostaining (blue), in control embryos not harboring the Tg(hsp:ifng1-2-V5) transgene (A), and Tg(hsp:ifng1-2-V5) embryos (B) are indicated by white circles. PCNA HSCs are marked with white arrowheads. (C) Percentage of PCNA⁺HSCs per total HSCs in the dorsal aorta. Values represent means ± SEM, n = 9 embryos per group, n.s., not significant (p > 0.05).

(D–M) Ifng1-2 and Crfb17 knockdown has no effect on apoptosis. Apoptotic cells (green, white arrowheads) visualized by Tg(Tbp:GAL4;UAS:secA5-YFP) expression (D–I) and TUNEL assay (J–M) in the axial vessels of MOCK-injected (D, G, and J), crfb17 MO-injected (E and L), and Ifng1-2 MO-injected (H and K) embryos at 52–54 hpf. Numbers of Tbp:GAL4;UAS:secA5-YFP⁺ cells (F and I) and TUNEL⁺kdrl:HRAS-mCherry⁺ cells per 500 µm dorsal aorta length (M) are shown as means ± SEM, n = 11–25 embryos, n.s. p > 0.05. All images are lateral views, dorsal up and anterior to the left.