Long-term hematopoietic stem cells (HSCs) have the ability to give rise to all of the blood cell types in an animal over its entire lifetime. Short-term HSCs, on the other hand, are only capable of self-renewing immediately following a destructive event. For these reasons, long term HSCs are the more valuable population when considering blood transplants. Zebrafish have long been recognized as a model system for studying developmental biology, but the first successful HSC transplants were reported just a few years ago. This early research looked only at short-term HSC repopulation, leaving long term repopulation (LTR) assays significantly underdeveloped. Recent work by HSCI Executive Committee chair Leonard Zon offers a reliable LTR assay to the field. Zon's team first identified the location of a set of genes responsible for immune-resistance in zebrafish DNA, allowing researchers to match donors and recipients based on their immuno-compatibility and reducing the potential for transplant rejection. Additionally, the team developed the specific conditions necessary for successful long-term repopulation studies, including a method for delivering precise numbers of donor cells and a statistical model to predict the long-term repopulation potential for any cell in the marrow. The work will advance all future zebrafish HSC experiments, which model human diseases such as bone marrow failure and hematopoietic cancers.

De Jong, J.; Burns, C.; Chen, A.; Pugach, E.; Mayhall, E.; Smith, A.; Feldman, H,; Zhou, Y,; Zon, L. (2011) Characterization of Immune-Matched Transplantation in Zebrafish. Blood. Feb 23. [Epub ahead of print]