title: Mapping hematopoiesis in a fully regenerative vertebrate: the axolotl.
abstract: Hematopoietic stem cell (HSC)-derived cells are involved in wound healing responses throughout the body. Unfortunately for mammals, wound repair typically results in scarring and nonfunctional reparation. Among vertebrates, none display such an extensive ability for adult regeneration as urodele amphibians, including 1 of the more popular models: the axolotl. However, a lack of knowledge of axolotl hematopoiesis hinders the use of this animal for the study of hematopoietic cells in scar-free wound healing and tissue regeneration. We used white and cytomegalovirus:green fluorescent protein(+) transgenic white axolotl strains to map sites of hematopoiesis and develop hematopoietic cell transplant methodology. We also established a fluorescence-activated cell sorter enrichment technique for major blood lineages and colony-forming unit assays for hematopoietic progenitors. The liver and spleen are both active sites of hematopoiesis in adult axolotls and contain transplantable HSCs capable of long-term multilineage blood reconstitution. As in zebrafish, use of the white axolotl mutant allows direct visualization of homing, engraftment, and hematopoiesis in real time. Donor-derived hematopoiesis occurred for >2 years in recipients generating stable hematopoietic chimeras. Organ segregation, made possible by embryonic microsurgeries wherein halves of 2 differently colored embryos were joined, indicate that the spleen is the definitive site of adult hematopoiesis.
authors.affiliation: Program in Stem Cell Biology and Regenerative Medicine, University of Florida, Gainesville, FL; Department of Molecular Genetics and Microbiology, University of Florida, Gainesville, FL;
authors.forename: David
authors.initials: D
authors.lastname: Lopez
authors.affiliation: Program in Stem Cell Biology and Regenerative Medicine, University of Florida, Gainesville, FL; Department of Molecular Genetics and Microbiology, University of Florida, Gainesville, FL;
authors.forename: Li
authors.initials: L
authors.lastname: Lin
authors.affiliation: Department of Biology, Northeastern University, Boston, MA;
authors.forename: James R
authors.initials: JR
authors.lastname: Monaghan
authors.affiliation: Program in Stem Cell Biology and Regenerative Medicine, University of Florida, Gainesville, FL; Division of Hematology and Oncology, Department of Medicine, University of Florida, Gainesville, FL;
authors.forename: Christopher R
authors.initials: CR
authors.lastname: Cogle
authors.affiliation: Department of Neurosurgery, University of Florida, Gainesville, FL; and.
authors.forename: Frank J
authors.initials: FJ
authors.lastname: Bova
authors.affiliation: Department of Biology, University of Florida, Gainesville, FL.
authors.forename: Malcolm
authors.initials: M
authors.lastname: Maden
authors.affiliation: Program in Stem Cell Biology and Regenerative Medicine, University of Florida, Gainesville, FL; Department of Molecular Genetics and Microbiology, University of Florida, Gainesville, FL;
authors.forename: Edward W
authors.initials: EW
authors.lastname: Scott
mesh_terms: D000558:Ambystoma mexicanum; D000818:Animals; D030801:Animals, Genetically Modified; D006085:Graft Survival / Q000502:physiology; D006410:Hematopoiesis / Q000502:physiology*; D018380:Hematopoietic Stem Cell Transplantation; D006412:Hematopoietic Stem Cells / Q000166:cytology* / Q000378:metabolism*; D012038:Regeneration / Q000502:physiology*