Chronological analysis with Fluorescent Timer reveals unique features of newly generated β cells

  1. Manami Hara5
  1. 1Department of Metabolism and Endocrinology,
  2. 2Center for Molecular Diabetology, Juntendo University Graduate School of Medicine, Tokyo, Japan,
  3. 3Department of Metabolic Medicine, Osaka University Graduate School of Medicine, Osaka, Japan,
  4. 4Diabetes Center, University of California San Francisco, San Francisco, California, USA,
  5. 5Department of Medicine, University of Chicago, Chicago, Illinois, USA
  1. 6Corresponding Author: Takeshi Miyatsuka, E-mail: miyatsuka-takeshi{at}


While numerous studies have uncovered the molecular mechanisms regulating pancreas development, it remains to be clarified how β cells arise from progenitors, and how recently specified β cells are different from pre-existing β cells. To address these questions, we developed a mouse model in which the insulin 1 promoter drives DsRed-E5 “Timer” fluorescence that shifts its spectrum over time. In the transgenic embryos, green-fluorescent β-cells were readily detected by FACS and could be distinguished from mature β cells only until postnatal day 0, suggesting that β cell neogenesis occurs exclusively during embryogenesis. Transcriptome analysis with green-fluorescent cells sorted by FACS demonstrated that newly differentiated β cells highly expressed progenitor markers, such as Sox9, Neurog3, and Pax4, showing the progenitor-like features of newborn β cells. Flow cytometric analysis of cell cycle dynamics showed that green-fluorescent cells were mostly quiescent, and differentiated β cells were mitotically active. Thus, the precise temporal resolution of this model enables us to dissect the unique features of newly specified insulin-producing cells, which could enhance our understanding of β cell neogenesis for future cell therapy.

  • Received August 25, 2013.
  • Accepted May 6, 2014.

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