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  • The EMBO Journal (1997) 16, 7432 - 7443
  • doi:10.1093/emboj/16.24.7432

Defective adipocyte differentiation in mice lacking the C/EBPbold beta and/or C/EBPdelta gene

Takashi Tanaka1, Nobuaki Yoshida2, Tadamitsu Kishimoto3 and Shizuo Akira1

  1. Department of Biochemistry, Hyogo College of Medicine, 1-1 Mukogawa-cho, Nishinomiya, Hyogo 663 Japan
  2. Research Institute, Osaka Medical Center for Maternal and Child Health, 840 Murodo-cho, Izumi, Osaka 590-02 Japan
  3. Osaka University Medical School, Department of Medicine III, 2-2 Yamada-oka, Suita, Osaka 565, Japan

Received 14 August 1997; Revised 25 September 1997

To investigate the role of C/EBP family members during adipocyte differentiation in vivo, we have generated mice lacking the C/EBPbeta and/or C/EBPdelta by gene targeting. Approximately 85% of C/EBPbeta(-/-)dotdelta(-/-) mice died at the early neonatal stage. By 20 h after birth, brown adipose tissue of the interscapular region in wild-type mice contained many lipid droplets, whereas C/EBPbeta(-/-)dotdelta(-/-) mice did not accumulate droplets. In addition, the epidydimal fat pad weight of surviving adult C/EBPbeta(-/-)dotdelta(-/-) mice was significantly reduced compared with wild-type mice. However, these adipose tissues in C/EBPbeta(-/-)dotdelta(-/-) mice exhibit normal expression of C/EBPalpha and PPARgamma, despite impaired adipogenesis. These results demonstrated that C/EBPbeta and C/EBPdelta have a synergistic role in terminal adipocyte differentiation in vivo. The induction of C/EBPalpha and PPARgamma does not always require C/EBPbeta and C/EBPdelta, but co-expression of C/EBPalpha and PPARgamma is not sufficient for complete adipocyte differentiation in the absence of C/EBPbeta and C/EBPdelta.

  • Keywords:

    • adipogenesis,
    • C,
    • EBP family,
    • PPARgamma,
    • transcription factor