Following the Cycle: Finally, a Transgenic Mouse to Sort Live Replicating Cells

Department of Genetics and Institute for Diabetes, Obesity & Metabolism, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA. Electronic address: .
Developmental Cell (Impact Factor: 9.71). 10/2012; 23(4):676-7. DOI: 10.1016/j.devcel.2012.10.006
Source: PubMed
Studies of the mammalian cell cycle in vivo have been hampered by the lack of pure populations of proliferating cells. In this issue of Developmental Cell, Klochendler and colleagues (2012) develop a novel transgenic mouse that expresses Cyclin B1-GFP ubiquitously. By sorting and analyzing proliferating hepatocytes, they provide evidence for their transient dedifferentiation.

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    Full-text · Article · Oct 2012 · Developmental Cell
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    [Show abstract] [Hide abstract] ABSTRACT: The molecular analysis of mammalian cellular proliferation in vivo is limited in most organ systems by the low turnover and/or the asynchronous nature of cell cycle progression. A notable exception is the partial hepatectomy model, in which quiescent hepatocytes reenter the cell cycle and progress in a synchronous fashion. Here we have exploited this model to identify regulatory networks operative in the mammalian cell cycle. We performed microarray-based expression profiling on livers 0-40 h post-hepatectomy corresponding to G0, G1, and S phases. Differentially expressed genes were identified using the statistical analysis program PaGE (Patterns from Gene Expression), which was highly accurate as confirmed by quantitative reverse transcription-PCR of randomly selected targets. A shift in the transcriptional program from genes involved in lipid and hormone biosynthesis in the quiescent liver to those contributing to cytoskeleton assembly and DNA synthesis in the proliferating liver was demonstrated by biological theme analysis. In a novel approach, we employed computational pathway analysis tools to identify specific regulatory networks operative at various stages of the cell cycle. This allowed us to identify a large cluster of genes controlling mitotic spindle assembly and checkpoint control at the 40-h time point as regulated at the mRNA level in vivo.
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