Transparent Adult Zebrafish as a Tool for In Vivo Transplantation Analysis

Abstract

The zebrafish is a useful model for understanding normal and cancer stem cells, but analysis has been limited to embryogenesis due to the opacity of the adult fish. To address this, we have created a transparent adult zebrafish in which we transplanted either hematopoietic stem/progenitor cells or tumor cells. In a hematopoiesis radiation recovery assay, transplantation of GFP-labeled marrow cells allowed for striking in vivo visual assessment of engraftment from 2 hr-5 weeks posttransplant. Using FACS analysis, both transparent and wild-type fish had equal engraftment, but this could only be visualized in the transparent recipient. In a tumor engraftment model, transplantation of RAS-melanoma cells allowed for visualization of tumor engraftment, proliferation, and distant metastases in as little as 5 days, which is not seen in wild-type recipients until 3 to 4 weeks. This transparent adult zebrafish serves as the ideal combination of both sensitivity and resolution for in vivo stem cell analyses.

How to make a teleost adenohypophysis: Molecular pathways of pituitary development in zebrafish

“…Here, one major advantage of the zebrafish system will be the high accessibility of the animals for both experimental manipulations and live imaging. The latter is further potentiated by the generation of A c c e p t e d M a n u s c r i p t 25 mutant strains that are even largely transparent during adulthood (White et al, 2008), and by the employment of transgenic reporter lines for live imaging on the cellular, subcellular and possibly even the molecular level.…”

Catch of the day: zebrafish as a human cancer model

“…The ability to perform large-scale genetic screens in zebrafish resulted in identification of several mutant (Her et al, 2003;Beis and Stainier, 2006;Wan et al, 2006;Kari et al, 2007;White et al, 2008). This would allow direct visualization of tumor progression and distant metastases using standard brightfield and fluorescence microscopy.…”

“…When crossed with the p53-deficient zebrafish line, the overexpression of BRAF V600E led to formation of highly invasive melanomas that had molecular characteristics similar to those of humans including mitogen-activated protein kinase activation (Patton et al, 2005). Recently, White et al (2008) transplanted BRAF V600E ; p53 melanoma cells into irradiated transparent adult casper mutant fish. The authors were able to monitor tumor progression and invasion into the distant tissues in the same animal for up to 1 month after transplantation using brightfield or fluorescent microscopy.…”

“…The embryos develop externally and are transparent up to 1 month of age (Spitsbergen, 2007;Stoletov et al, 2007). Adult, casper mutant (roy À/À ;nacre À/À ) animals are also available that remain transparent throughout life and are amenable to in vivo transplantation studies (Figure 1) (White et al, 2008). The remarkable transparency of zebrafish tissues allows direct imaging of cancer progression including cell invasion, intravasation, extravasation and angiogenesis (Stoletov et al, 2007;White et al, 2008).…”

“…Adult, casper mutant (roy À/À ;nacre À/À ) animals are also available that remain transparent throughout life and are amenable to in vivo transplantation studies (Figure 1) (White et al, 2008). The remarkable transparency of zebrafish tissues allows direct imaging of cancer progression including cell invasion, intravasation, extravasation and angiogenesis (Stoletov et al, 2007;White et al, 2008). A complete sequence of the zebrafish genome is available and many human cancer genes are conserved structurally and functionally in zebrafish (http://www.ncbi.nlm.nih.gov/genome/guide/zebrafish).…”