Generation of foxn1 / Casper Mutant Zebrafish for Allograft and Xenograft of Normal and Malignant Cells

Cell transplantation into immunodeficient recipients is a widely-used approach to study stem cell and cancer biology; however, studying cell states post transplantation in vivo is inconvenient in mammals. Here, we generated a zebrafish foxn1/Casper mutant that is transparent and immunodeficient with deficient T cells. By employing the mutant for hematopoietic stem cell transplantation (HSCT), we could achieve nonconditioned transplantation. Meanwhile, we found that fetal HSCs from 3 days post fertilization produce a better transplant outcome in adult recipients, compared to adult HSCs. Furthermore, adult HSCs from the newly generated Tg (runx1:en-GFP) line have higher engraftment efficiency than that from the Tg (CD41:GFP) line. In addition to HSCT, foxn1/Casper mutant is feasible to allogeneic leukemia and muscle cell transplantation, as well as xenogenic medaka HSCT. Collectively, foxn1/Casper mutant permits the nonconditioned engraftment of multiple cell types with superiority in imaging and characterization of transplanted cells at single cell resolution in vivo.