Fig. 3.

Mitochondrial-derived ROS production in endothelial cells is required for haemogenic endothelium induction and the specification of HSPCs. (A) Schematic showing the region of 16 hpf embryos which was analysed by fluorescence microscopy in B and C. (B) Fluorescence microscopy images of total cellular ROS detection in kdrl:GFP⁺ or cx41.8^tq/tq;kdrl:GFP⁺ embryos. White arrowheads denote the presence of ROS in endothelial cells. Numbers indicate the ratio of embryos with the respective phenotype. (C) Fluorescence microscopy images of mitochondrial-derived ROS detection in kdrl:GFP⁺ or cx41.8^tq/tq;kdrl:GFP⁺ embryos. White arrowheads denote mitochondrial-derived ROS in endothelial cells. Numbers indicate the ratio of embryos with the respective phenotype. (D) Quantification of aortic runx1 signal (in situ hybridisation) at 28 hpf in WT control embryos and those treated with MitoTEMPO, NAC, GSH, heptanol or CBX. (E) Quantification of aortic gata2b signal (in situ hybridisation) at 23 hpf in cx41.8^tq/tq control embryos and cx41.8^tq/tq embryos treated with H₂0₂ or menadione. (F) Quantification of aortic runx1 signal (in situ hybridisation) at 28 hpf in cx41.8^tq/tq control embryos and cx41.8^tq/tq embryos supplemented with H₂0₂ and menadione. Statistical significance was calculated using a Chi-squared test. *P<0.05, **P<0.01, ***P<0.001, ****P<0.0001. Scale bars: 25 μm (B and C). Created in BioRender by Petzold, T., 2025. https://BioRender.com/n88jg67. This figure was sublicensed under CC-BY 4.0 terms.