Hematopoietic cell transplantation rescues survival of the minimum lethal dose. (A) Kaplan-Meier survival curves of adult zebrafish receiving a dose of 40 Gy with (red line) or without (blue line) transplantation of 1 × 106 WKM. All irradiated animals not receiving transplants died by 14 days. By contrast, more than 70% of animals that received a transplant survived for at least 30 days. (B-G) Animals receiving transplants of transgenic β-actineGFP WKM cells that survived 30 days showed robust reconstitution of hematolymphoid tissues by donor-derived cells, including the kidney (B-C), thymus (D-E), and spleen (F-G). Sections stained for GFP are serial sections following those stained with hematoxylin and eosin and are separated by 4 to 12 μm. Dashed yellow lines demarcate glomeruli; red chevrons, erythrocytes; and green chevrons, leukocytes. T indicates renal tubules; and L, liver. Scale bar equals 20 μm. (H) Transplantation of double-transgenic β-actineGFP × GATA-1dsRED WKM allows visualization of multilineage hematopoietic reconstitution in living recipients. Still image from the Supplemental Video (see the Supplemental Video link at the top of the online article on the Blood website) shows a closeup (× 100) view of the capillary network in the tail of an HCT recipient at 30 days after transplantation. Arrows denote donor-derived leukocytes and arrowheads show donor-derived erythrocytes. Asterisk denotes regions of skin autofluorescence.
