Paracrine action of FGF4 during periimplantation development maintains trophectoderm and primitive endoderm

Authors

  • Sarah N. Goldin,

    1. Department of Genetics and Development, College of Physicians and Surgeons of Columbia University, New York, New York
    Search for more papers by this author
  • Virginia E. Papaioannou

    Corresponding author
    1. Department of Genetics and Development, College of Physicians and Surgeons of Columbia University, New York, New York
    • Department of Genetics and Development, College of Physicians and Surgeons of Columbia University, 701 West 168th Street, New York, NY 10032
    Search for more papers by this author

Abstract

Summary: FGF4, a member of the fibroblast growth factor (FGF) family, is absolutely required for periimplantation mouse development, although its precise role at this stage remains unknown. The nature of the defect leading to postimplantation lethality of embryos lacking zygotic FGF4 is unclear and little is known about downstream targets of FGF4-initiated signaling within the various cellular compartments of the blastocyst. Here we report that postimplantation lethality of Fgf4−/− embryos is unlikely to reflect strictly mitogenic requirements for FGF4. Rather, our results suggest that FGF4 is required to maintain trophectoderm and primitive endoderm identity at embryonic day 4.5. This result is consistent with the reported in vitro activity of FGF4 in maintaining trophoblast stem cells and with the requirement for receptor tyrosine kinase signaling in primitive endoderm formation. Thus, postimplantation lethality of Fgf4−/− embryos likely results from the failure of proper differentiation and function of extraembryonic cell types. genesis 36:40–47, 2003. © 2003 Wiley-Liss, Inc.

Ancillary