title: Intra-hematopoietic cell fusion as a source of somatic variation in the hematopoietic system.
abstract: Cell fusion plays a well-recognized, physiological role during development. Bone-marrow-derived hematopoietic cells have been shown to fuse with non-hematopoietic cells in a wide variety of tissues. Some organs appear to resolve the changes in ploidy status, generating functional and mitotically-competent events. However, cell fusion exclusively involving hematopoietic cells has not been reported. Indeed, genomic copy number variation in highly replicative hematopoietic cells is widely considered a hallmark of malignant transformation. Here we show that cell fusion occurs between cells of the hematopoietic system under injury as well as non-injury conditions. Experiments reveal the acquisition of genetic markers in fusion products, their tractable maintenance during hematopoietic differentiation and long-term persistence after serial transplantation. Fusion events were identified in clonogenic progenitors as well as differentiated myeloid and lymphoid cells. These observations provide a new experimental model for the study of non-pathogenic somatic diversity in the hematopoietic system.
authors.affiliation: Department of Pediatrics, Papé Family Pediatric Research Institute, Oregon Health and Science University, Portland, OR 97239-3098,  USA.
authors.forename: Amy M
authors.initials: AM
authors.lastname: Skinner
authors.forename: Markus
authors.initials: M
authors.lastname: Grompe
authors.forename: Peter
authors.initials: P
authors.lastname: Kurre
mesh_terms: D000818:Animals; D002454:Cell Differentiation; D002459:Cell Fusion; D002478:Cells, Cultured; D056915:DNA Copy Number Variations; D005260:Female; D014644:Genetic Variation; D018380:Hematopoietic Stem Cell Transplantation; D006412:Hematopoietic Stem Cells / Q000166:cytology*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL