Fig. 1: Deletion of HSP60 by Tie2-Cre in mice resulted in reduced numbers of yolk sac erythrocytes and anemia.

a Whole-mount immunofluorescence staining was used to examine the expression of HSP60 in control and HSP60^CKO yolk sac erythrocytes at E8.5. Data are representative of at least three independent experiments. Scale bar, 20 μm. b Morphology of control and HSP60^CKO yolk sacs and embryos isolated at E9.5 and E10.5, indicating that red blood cells (red arrows) can be easily observed in control yolk sac vitelline vessels and embryo dorsal aorta at both stages, whereas HSP60^CKO yolk sacs and embryos appear extremely pale. Scale bar, 0.5 mm. c Embryos with yolk sacs at E8.5 were stained with benzidine, which stains all hemoglobin-containing cells blue. d Whole-mount GATA1 immunofluorescence staining was used to calculate the numbers of erythrocytes in the whole yolk sacs at E8.5 and E9.0, respectively. Each picture was stitched with 3–4 individual images captured on the same yolk sac. Scale bar, 0.5 mm. e Numbers of GATA1 positive cells were calculated in control and HSP60^CKO yolk sacs at E8.5 and E9.0, respectively. n = 4 mice per group. All data represent mean ± SEM. Significance was determined using a 2-tailed, unpaired Student’s t test. *p < 0.05 versus control