title: Bimolecular fluorescence complementation analysis of eukaryotic fusion products.
abstract: BACKGROUND
  Cell fusion is known to underlie key developmental processes in humans and is postulated to contribute to tissue maintenance and even carcinogenesis. The mechanistic details of cell fusion, especially between different cell types, have been difficult to characterize because of the dynamic nature of the process and inadequate means to track fusion products over time. Here we introduce an inducible system for detecting and tracking live cell fusion products in vitro and potentially in vivo. This system is based on BiFC (bimolecular fluorescence complementation) analysis. In this approach, two proteins that can interact with each other are joined to fragments of a fluorescent protein and are expressed in separate cells. The interaction of said proteins after cell fusion produces a fluorescent signal, enabling the identification and tracking of fusion products over time.
  
  
  RESULTS
  Long-term tracking of fused p53-deficient cells revealed that hybrid cells were capable of proliferation. In some cases, proliferation was preceded by nuclear fusion and division was asymmetric (69%+/-2% of proliferating hybrids), suggesting chromosomal instability. In addition, asymmetric division following proliferation could give rise to progeny indistinguishable from unfused counterparts.
  
  
  CONCLUSIONS
  These results support the possibility that the chromosomal instability characteristic of tumour cells may be incurred as a consequence of cell fusion and suggest that the role of cell fusion in carcinogenesis may have been masked to this point for lack of an inducible method to track cell fusion. In sum, the BiFC-based approach described here allows for comprehensive studies of the mechanism and biological impact of cell fusion in nature.
authors.affiliation: Department of Biomedical Engineering, University of Wisconsin-Madison, Madison, WI 53706, USA.
authors.forename: Ho-Pi
authors.initials: HP
authors.lastname: Lin
authors.forename: Claudius
authors.initials: C
authors.lastname: Vincenz
authors.forename: Kevin W
authors.initials: KW
authors.lastname: Eliceiri
authors.forename: Tom K
authors.initials: TK
authors.lastname: Kerppola
authors.forename: Brenda M
authors.initials: BM
authors.lastname: Ogle
mesh_terms: D000818:Animals; D019556:COS Cells; D002455:Cell Division; D002459:Cell Fusion; D049109:Cell Proliferation; D002522:Chlorocebus aethiops; D043171:Chromosomal Instability; D005453:Fluorescence; D006822:Hybrid Cells / Q000166:cytology / Q000502:physiology*; D008163:Luminescent Measurements / Q000379:methods*; D008164:Luminescent Proteins / Q000378:metabolism; D008856:Microscopy, Fluorescence / Q000379:methods*; D011485:Protein Binding; D011993:Recombinant Fusion Proteins / Q000378:metabolism
chemical_list: D008164:Luminescent Proteins; D011993:Recombinant Fusion Proteins