Submitted February 4, 2009
Accepted April 17, 2009
Zebrafish kidney stromal cell lines support multilineage hematopoiesis
David L Stachura, Jason R Reyes, Petr Bartunek, Barry H. Paw, Leonard I. Zon, and David Traver*
University of California at San Diego Division of Biological Sciences, Section of Cell and Developmental Biology, La Jolla, CA, United States
Institute of Molecular Genetics AS CR v.v.i., Prague, Czech Republic
Division of Hematology, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, United States
Children's Hospital Boston, Department of Medicine, Boston, MA, United States
* Corresponding author; email: dtraver{at}ucsd.edu.
Studies of zebrafish hematopoiesis have been largely performed using mutagenesis approaches and retrospective analyses based upon gene expression patterns in whole embryos. We previously developed transplantation assays to test the repopulation potentials of candidate hematopoietic progenitor cells. We have been impaired, however, in determining cellular differentiation potentials by a lack of short-term functional assays. To enable more precise analyses of hematopoietic progenitor cells, we have created zebrafish kidney stromal (ZKS) cell lines. Culture of adult whole kidney marrow with ZKS cells results in the maintenance and expansion of hematopoietic precursor cells. Hematopoietic growth is dependent upon ZKS cells, and we show that ZKS cells express many growth factors and ligands previously demonstrated to be important in maintaining mammalian hematopoietic cells. In the absence of exogenous growth factors, ZKS cells maintain early hematopoietic precursors and support differentiation of lymphoid and myeloid cells. With the addition of zebrafish erythropoietin, ZKS cells also support the differentiation of erythroid precursors. These conditions have enabled the ability to ascertain more precisely the points at which hematopoietic mutants are defective. The development of robust in vitro assays now provide the means to track defined, functional outcomes for prospectively isolated blood cell subsets in the zebrafish.
